VOL. 17, NO. 5 – 2020

GEOSCIENCE & TECHNOLOGY EXPLAINED

geoexpro.com

EXPLORATION GEO PHYSICS CSEM: Back from Underexplored the Brink African Source Rocks

ENERGY TRANSITION Hydrogen and CCS in Future Energy

GEO TOURISM Sailing Through a Subduction Zone

INDUSTRY ISSUES Tackling the Local Content Gap

GEOExPro October 2020 1

Previous issues: www.geoexpro.com Contents Vol. 17 No. 5

This edition of GEO ExPro focuses on Africa; GEOSCIENCE & TECHNOLOGY EXPLAINED Non-Seismic Geophysics; Carbon Capture, Storage and Utilisation; and the Energy Transition.

26 The Irrawaddy River valley – a 5 Editorial stunning mix of beautiful scenery and ancient and modern culture. 6 Regional Update: A Bleak Year 8 Licensing Update: Norway Surprises Lon Abbott and Terri Cook 10 A Minute to Read

30 14 Cover Story: Exploration: Imaging the subsurface with Enhanced Underexplored African Source Rocks Full Tensor Gravity Gradiometry. 20 Seismic Foldout: Kwanza Shelf – New 3D Seismic Imaging 26 GEO Tourism: Sailing Through a

AustinBridgeporth Subduction Zone 30 Technology Explained: Egypt’s Buried 48 Secrets The role of the geoscientist is an important one in the future 32 Energy Transition: Hydrogen and CCS energy transition. in Future Energy 36 Hot Spot: The Hotspot That Keeps On Giving CMG 38 GEO Physics: CSEM – Back From the 52 Brink CO2 is an unwanted gas but its effect can be mitigated by using it for 42 Seismic Foldout: Offshore Somalia . Could Reveal an Oily Surprise 48 Energy Transition: Geoscience in a Low Carbon Future

52 Energy Transition: Ruminations on CO₂ 56 The Onshore Kwanza Basin in 56 Exploration: Tantalising Opportunities Angola is underexplored and in Angola offers tantalising potential. 60 Industry Issues: Tackling the Local

canstockphoto Content Gap 64 Seismic Foldout: Gabon – Staying 8 Ahead of the Herd 70 Exploration: A Global Exploration 72 11 75 Hotspot 30 72 GEO Media: Geological Tours of North 26 74 60 36 6 America’s Wonders 42 64 14 56 74 Exploration Update 20 12 70 76 FlowBack 74

GEOExPro September 2020 3

Editorial

Aiming for Net Zero GEOSCIENCE & TECHNOLOGY EXPLAINED Many companies involved in www.geoexpro.com the oil industry are at pains to explain how they are going to go GeoPublishing Ltd green. , BP and Shell have Shutterstock 15 Palace Place Mansion all announced plans to reach Kensington Court London W8 5BB, UK net zero by 2050, while says +44 20 7937 2224 it will cut its greenhouse gas emissions by 80% in the same Managing Director timescale. On the other side of Tore Karlsson the Atlantic, ExxonMobil and Editor in Chief Chevron have not set long- Jane Whaley term greenhouse gas emissions [email protected] reduction targets, but they have Editorial enquiries committed to reductions in GeoPublishing methane emissions and cuts in fl aring and are involved in projects to develop low emissions Jane Whaley energy solutions. +44 7812 137161 But, as ExxonMobil’s Chairman wrote in the company’s 2020 Energy and Carbon [email protected] Summary: “Energy is essential. Accessible and aff ordable supplies of energy support our www.geoexpro.com ability to meet the basic requirements of life and fuel society’s progress around the world”. Sales and Marketing Director And therein lies the core of the issue: how to reduce emissions, transition to a low carbon Kirsti Karlsson environment – and still manage to increase access to energy and electricity in the many parts +44 79 0991 5513 of the world that are only just beginning to appreciate the benefi ts that those of us living in [email protected] the more developed countries have been enjoying for decades. Th ere is an interesting picture on the last page of our cover story that illustrates this admirably. Would digging holes in a sandy river bed to grab a saucepan-full of fresh water be a thing of the past if these people had access to electric pumps? Subscription To make that a possibility, it appears that all scenarios for the energy transition indicate GeoPublishing Ltd that fossil fuels, particularly gas, will be around for some time, as will be the inevitable CO₂ +44 20 7937 2224 emissions. In this edition we discuss how CO₂ can usefully be employed in enhanced oil 15 Palace Place Mansion recovery, rather than just pumping it into the atmosphere. We also look at Kensington Court London W8 5BB, UK the idea of hydrogen as an energy source, which has been gaining ground [email protected] recently, but most techniques for making hydrogen require electricity, so carbon capture and storage is needed if the power source is not green. GEO ExPro is pub lished bimonthly Reducing emissions is an important goal but it must be approached for a base subscrip tion rate of GBP 60 a year (6 issues). globally. It is no use if one country or company claims to have reduced We encourage readers to alert us its carbon footprint if the polluting industry or process has simply to news for possible publication shifted elsewhere where there are less stringent environmental controls. and to submit articles for publication. Jane Whaley Achieving net zero is a complex issue. Editor in Chief Cover Photograph: Main Image: Mike Rego Inset: OFG Multiphysics

UNDEREXPLORED AFRICAN SOURCE ROCKS Layout: Mach 3 Solutions Ltd Villagers carrying fruit to market along a road climbing the fl ank of the Print: Stephens & George, UK Makonde Plateau in southern Tanzania. This escarpment represents the westernmost onshore extent of the sediments that make up the Rovuma issn 1744-8743 Basin. The sandstones and shales here are currently interpreted to be Lower Cretaceous in age and require examination for source potential, since these sediments are the basin margin equivalents of those hosting the supergiant gas discoveries of the Rovuma Basin. Inset: CSEM is a proven technology that should be routinely considered to help solve certain classes of E&P challenges, especially when seismic data alone cannot provide a satisfactory answer.

© 2020 GeoPublishing Limited. Copyright or similar rights in all material in this publication, including graphics and other media, is owned by GeoPublishing Limited, unless otherwise stated. You are allowed to print extracts for your personal use only. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means electronic, mechanical, photographic, recorded or otherwise without the prior written permission of GeoPublishing Limited. Requests to republish material from this publication for distribution should be sent to the Editor in Chief. GeoPublishing Limited does not guarantee the accuracy of the information contained in this publication nor does it accept responsibility for errors or omissions or their consequences. Opinions expressed by contributors to this publication are not necessarily those of GeoPublishing Limited.

GEOExPro October 2020 5 Regional Update

A Bleak Year ABBREVIATIONS 2020 is the bleakest year in a decade for African oil and gas exploration. Numbers (US and scientifi c community) Expectations were high at the start of this year for some keenly anticipated oil and gas exploration M: thousand = 1 x 103 wells on the African continent. However, most of these high-impact wells have now been delayed MM: million = 1 x 106 or deferred due to the twin impact of the oil price crash and the Covid-19 pandemic. B: billion = 1 x 109 Only 20 exploration wells have been drilled in Africa so far this year, and overall well T: trillion = 1 x 1012 activity has dropped about 72% from last year. Th is means the continent will struggle even to replicate 2018, which had the lowest number of African exploration wells (52) drilled in the past decade. Across Africa barely 270 wells have been drilled in the past fi ve years, which is Liquids approximately equivalent to the total well count from 2014 alone. barrel = bbl = 159 litre Th e search for new volumes through exploratory drilling has seen around 41.5 Bboe boe: barrels of oil equivalent discovered in Africa over the past nine years. Gas dominates over liquids, with around 73% of bopd: barrels (bbls) of oil per day bcpd: bbls of condensate per day the cumulative discovered resource during this period. Last year was the most successful since bwpd: bbls of water per day 2015 with about 3 Bboe of new volumes discovered. UK supermajor BP’s Orca gas discovery in Mauritania was not only the deepest but also the largest discovery in Africa in 2019, and the fi fth-largest in the past nine years. In addition, 2019 expanded Africa’s exploration potential Gas with Total’s basin-opening Brulpadda discovery in Block 11B/12B in South Africa. Brulpadda MMscfg: million ft3 gas not only de-risked the additional prospects available within the block, but also ignited hopes in MMscmg: million m3 gas South Africa that it would be able to reduce its overall gas imports. Tcfg: trillion cubic feet of gas Discovered resources and year-on-year well activity change. Ma: Million years ago

LNG Liquifi ed Natural Gas (LNG) is natural gas (primarily methane) cooled to a temperature of approximately -260 oC.

NGL Natural gas liquids (NGL) include propane, butane, pentane, hexane and heptane, but not methane and Rystad Energy ECube, Rystad Energy research and analysis ethane.

Reserves and resources Th is year has not turned out as anticipated, however, and the continent is yet to announce P1 reserves: a major discovery. Th e only notable success is Eni’s twin discoveries from the Greater Nooros Quantity of hydrocarbons believed Area in the Mediterranean Sea off Egypt, with cumulative resources of about 4 Tcfg. Total recoverable with a 90% probability spudded its fi rst African well of the year in late August with the Luiperd prospect in South Africa, which will test the extension of the Brulpadda play. A whole host of licensing rounds were scheduled to be held this year in African countries, P2 reserves: including Algeria, Senegal, South Sudan, Sierra Leone, Ghana, Congo, Angola, Egypt, Sudan, Quantity of hydrocarbons believed Uganda, Somalia, Liberia, Mozambique and Nigeria. Now most of these rounds are either recoverable with a 50% probability suspended until further notice or delayed, and the Nigerian marginal fi eld round is the only one that has been able to attract signifi cant interest. Some countries like Somalia and Liberia, P3 reserves: which are hosting their fi rst-ever rounds, have already started accepting bids for off ered Quantity of hydrocarbons believed blocks but have pushed back the deadline to the second quarter of 2021. recoverable with a 10% probability We also expect that the highly anticipated wells of 2020 that may be spudded by the end of this year will be completed in 2021. Th is could include the likes of Total’s Venus prospect off Namibia, considered to be largest prospect in the ultra-deep waters in Block 2913B. Similarly, Oilfi eld glossary: the result of Total’s Ondjaba well in Angola’s Block 48 may also be deferred to early 2021. www.glossary.oilfi eld.slb.com Th ese wells hold signifi cant importance, as Namibia looks to register its fi rst success since the Kudu fi eld was found in 1974 and Angola searches for new volumes to reverse the decline in the country’s hydrocarbon production. Aatisha Mahajan, Rystad Energy

6 GEOExPro October 2020 GEOExPro October 2020 7 Licensing Update Norway Surprises Quaternary Known for being a country with some of the greenest credentials 2.6 and policies in the world, Norway surprised many observers in Neogene Tertiary June by announcing plans for a licensing round that signalled a 23

major expansion of the availability of areas for oil exploration in the Cenozoic Norwegian sector of the Arctic Sea. Paleogene In preparation for the country’s 25th licensing round, which is 66* scheduled for 2021, the Ministry of and Energy sought public consultation on the proposal, which includes eight areas in Cretaceous the Arctic Barents Sea covering 125 blocks, as well as 11 blocks in the Norwegian Sea. It has already made an assessment of the petroleum South Atlantic starts South opening Atlantic Alpine orogeny Alpine potential of these areas, and after the inputs from the consultation period, which ended in August 2020, have been assessed, the 25th 145 licensing round is likely to be announced during the autumn of 2020. orogeny Laramide Th e deadline for applications is expected in the new year, with award Jurassic

announcements expected in the second quarter of 2021. Mesozoic

Th e announcement brought condemnation from environmental groups, breakup Pangaea especially since about half of the suggested blocks lie in the northern part 201*

of the Barents Sea between 73°N and 74°N, potentially some of the most Norwegian-Greenland Sea starts opening northerly off shore oil exploration in the world. Others are close to the Triassic North Sea rifting Svalbard zone and will therefore probably be disputed by . Over the years Norway has been vocal in its commitments to tackling 252* global warming and reducing its use of fossil fuels. Th e country’s sovereign wealth fund, derived from the profi ts from its petroleum resources, Permian recently said that it would divest itself of any stakes in companies that are solely dedicated to oil and gas exploration and production.

Central Atlantic starts opening Atlantic Central 299 Norway has a system with two forms of licence round. Numbered Phanerozoic Carboniferous rounds, held every two years, are based on less well-known areas on the

Norwegian shelf, where there is greater risk but a higher chance of large rifting discoveries, while the annual allocations in predefi ned areas (APA), are Extinction Events Big Five The * announced every year and comprise the mature parts of the shelf, with known geology and good infrastructure. When the consultation period 359* was announced the Norwegian Minister of Petroleum and Energy, Tina Devonian Bru, stated that “Regular access to new exploration areas is crucial to OF PANGAEA FORMATION maintaining activity on the Norwegian continental shelf. We need new discoveries to uphold employment and value creation”. Paleozoic 419 Silurian 443* Ordovician Variscan orogeny Variscan

486

Caledonia orogeny Caledonia Cambrian

The Great Unconformity 541

Proposed new blocks Licensed areas Areas not available for drilling Precambrian

Pre-defi ned area for drilling Neoproterozoic

8 GEOExPro October 2020 GEOExPro October 2020 9 A Minute to Read… News from around the world

New Way and New Name PetroMarker has over the summer gone through a rebranding process and changed Allton the company name to Allton. As part of the whole energy transition shift occurring in the oil and gas industry it was a suitable time to change the company name and technology focus. Electromagnetics (EM) have primarily been used for frontier exploration, regional studies and drill or drop decisions. Allton will focus the technology development not only to improve frontier and near-fi eld exploration services; there will also be a strong technology commitment to deliver EM services for 4D oil and gas monitoring. Th e implementation and use of 4D EM technology in oil and gas production will in many cases increase the recovery rate of existing and new fi elds, improving the economics and reducing the carbon footprint. Th e increased focus on off shore CO₂ storage such as the Northern Lights project in Norway will require a secure and reliable measurement, monitoring and verifi cation tool. Allton’s EM technology will be that tool, which can deliver on these promises to make sure that the CO₂ is stored safely. OPEC Turns 60

September 14, 2020 marked the 60th anniversary of the founding of one of the most infl uential global organisations ever:OPEC (Organization of the Petroleum Exporting Countries). Until its formation, the was determined by the major Anglo-American oil companies, including the forerunners of Exxon, Mobil, Chevron, Shell and BP. Owning large swathes of concessions across the developing world, these companies eff ectively controlled the exploration, production, distribution and sale of oil in the non-Communist countries through informal (and possibly not legal) agreements between themselves to limit production and thus control prices. At a conference in Baghdad in September 1960 the leaders of Iran, Iraq, Kuwait,

Saudi Arabia and Venezuela agreed to form an intergovernmental organisation, the OPEC aims of which were to “co-ordinate and unify petroleum policies among Member The Iraqi delegation to the OPEC founding Countries, in order to secure fair and stable prices for petroleum producers; an conference. effi cient, economic and regular supply of petroleum to consuming nations; and a fair return on capital to those investing in the industry”. Th ese countries were later joined by Qatar, Indonesia, Libya, United Arab Emirates, Algeria, Nigeria, Ecuador, Equatorial Guinea, Gabon, Angola and Congo, although some of the members have since left the organisation, and there are 13 member states at present (see GEO ExPro Vol. 7, No. 5 for more on the history of OPEC). OPEC came to prominence in October 1973, when, with oil at about $2 a barrel, the cartel increased its prices unilaterally, at the same time reducing production. Oil prices rose and shortages were felt in oil-consuming countries, while the global economy went into recession. From this point onwards, OPEC took a central role in the oil economy, with the biggest-producing member, , often acting as a swing producer in eff orts to control the market. However, as more and more prolifi c non-OPEC regions, like Alaska, the North Sea and deepwater Brazil, were opened up, the cartel eff ectively controlled a reducing percentage of the market. With the rise of shale oil production in the US – encouraged by oil prices that peaked at $147.50 for – OPEC fi nally lost the consensus that had operated between the member states, which ultimately resulted in the dramatic price drops seen between 2014 and 2016. In the last few years it has joined forces with a number of other countries, notably Russia, forming ‘OPEC+’ in eff orts to manage global oil production and raise prices, but with limited success. In the changing world of the mid-20th century, with many countries being released by colonial powers to form independent states, OPEC certainly had an important role to play. With a transformed petroleum landscape where diff erent powers hold infl uence, plus the emerging energy transition which also tilts the global power balance, OPEC now accounts for about 25% of all oil produced globally; still a signifi cant amount, and the organisation remains important, particularly for many of the member states for whom oil is their primary source of revenue.

10 GEOExPro October 2020 New Material for Carbon Capture

Scientists from ExxonMobil, University of California, Berkeley and Lawrence Berkeley National Laboratory have discovered a new material that could capture more than 90% of CO₂ emitted from industrial sources, such as natural gas- fired power plants. Results of the research were published in July in the international peer-reviewed journal, Science. Laboratory tests indicate the patent-pending materials, known as tetraamine-functionalised metal organic frameworks, capture CO₂ emissions up to six times more effectively than conventional carbon capture technology. By manipulating the structure of the metal’s organic framework material, the team of scientists and students demonstrated the ability to condense a surface area the size of a football field into just one gram of mass that acts as a sponge for CO₂. The materials have much greater capacity for capturing CO₂ and can be regenerated for repeated use by using low-temperature steam, requiring less energy for the overall carbon capture process. This means that the material has the potential to reduce the cost of the technology and eventually support commercial applications. Since 2000, ExxonMobil has invested approximately $10 bn in projects to research, develop and deploy lower- emission energy solutions and is working with more than 80 universities, five energy centres and multiple private sector partners around the world to explore next-generation energy technologies. New Cloud Collaboration

Schlumberger, IBM and Red Hat have joined in a major Virtual PROSPEX 2020 collaboration aimed to accelerate digital transformation across the oil and gas industry. The joint initiative will provide Join the Petroleum Society of Great Britain (PESGB) for global access to ’s leading exploration and #PROSPEX2020 – delivered as a fully virtual event! production cloud-based applications by leveraging IBM’s Enjoy keynotes from the Norwegian Petroleum Directorate, hybrid cloud technology, built on the Red Hat OpenShift Westwood Global Energy and the event partner, Oil & Gas container platform, which will allow the deployment of Authority; as well as presentations from companies with applications in Schlumberger’s DELFI* cognitive E&P exciting prospects and investment opportunities across the environment across any infrastructure, from traditional data two-day conference. You will also hear from leading experts as centres to multiple clouds, including private and public. This they consider how the future may look for the industry in the new way of hosting will offer the possibility of using multiple aftermath of this turbulent year. cloud providers and will address critical issues for customers, This first-ever virtualPROSPEX will deliver a much facilitating in-country deployments in compliance with local more diverse event and promote a broader set of investment regulations and data residency requirements. opportunities to a worldwide audience for the first time. The DELFI environment incorporates cutting-edge data You can immerse yourself on the dedicated PROSPEX event analytics and artificial intelligence, drawing upon multiple platform and connect with the event sponsors, exhibitors data sources, automating workflows, and facilitating seamless and fellow attendees through open discussion boards, ‘chat’ collaboration for domain teams. dialogue and private messaging. There will also be a virtual Collaborative development will initially focus on two exhibition to help facilitate those all-important business key areas: the private, hybrid or multi-cloud deployment of negotiations and lots of additional networking opportunities DELFI, enabled by Red Hat OpenShift, to significantly expand to get involved with! access for customers; and delivery of the first hybrid cloud Registration Rates: PESGB Members: £145.00 + VAT; Non- implementation of the industry’s open data platform (OSDU™). Members: £190.00 + VAT. The companies believe that a hybrid cloud foundation Find out more about PROSPEX 2020, including exhibitor built on open source offers the flexibility, acceleration and and sponsor opportunities, and book your place at the innovation that the digital transformation of the oil and gas PROSPEX website. industry requires.

GEOExPro October 2020 11 A Minute to Read… News from around the world

WiNG for Turkey Leading designer and manufacturer of innovative seismic equipment and reservoir monitoring instruments, Sercel, recently announced that it had completed its fi rst delivery ofWiNG NT, its next- generation wireless land nodal acquisition system. Th e purchaser was the Turkish Petroleum International Company and the system will be used for upcoming seismic acquisition projects in diffi cult-to- access mountainous areas of Turkey. WiNG is a fully integrated nodal land acquisition system designed with a single data collection platform to manage operations more easily and effi ciently. It integrates Sercel’s most sensitive broadband sensor Sercel ever, QuietSeis®, to acquire high precision seismic data. Th e node has been designed to minimise storage and transportation costs and, although weighing less that a kilogramme, it can record seismic data for up to 50 days. Th e data is delivered via the Data Completion Manager, a unique central software platform that signifi cantly improves and automates the assignment of data collected in the fi eld, while allowing for remote quality control and monitoring. Onshore Argentina Explorers Package

Despite having an exploration history that goes back to the 1880s, the Neuquén and Cuyo Basins in the Mendoza province of Argentina still have signifi cant conventional and unconventional potential. To address this, global multi-client geoscience provider Searcher recently announced the expansion of its Argentina data library with the Onshore Mendoza Explorers Package, which includes seismic and well data specifi cally aimed at explorers in these two basins. Th e package includes vintage 2D and 3D data to which Searcher has applied its proprietary post-stack reprocessing method to rectify navigation, metadata, amplitude, phase, and time, thus creating a contiguous database that can be easily loaded into any interpretation software. Th e dataset comprises about 40,000 km of 2D and 10,000 km2 of 3D seismic. Also included in the package is the Mendoza Well Atlas, which consists of 50 wells for which Searcher’s G&G team, Discover Geoscience, has undertaken a post-drill well analysis of the key exploration and discovery wells across the basins. Th e resulting well atlas covers both conventional and unconventional plays. Th e data is accessed via a simple web interface, allowing screening and downloading from anywhere in the world. Th e presence of the Vaca Muerta world class source rock in the Neuquén and Cuyo Basins, as well as proven prolifi c reservoirs with many traps still undrilled, makes this is a very exciting province in which to explore. Delivering Greater Understanding with AI

AI interpretation delivers through the power of people, science and technology. Software specialist has combined over Geoteric Geoteric 30 years of geological experience with an in-depth knowledge of AI to develop two new technologies that will help deliver greater understanding of subsurface geology. Th e fi rst is the new Collaborative AI software that, while being closely aligned to traditional interpretation techniques, can improve interpretation and effi ciently extract faults from seismic data at the click of a button. It complements existing Geoteric workfl ows and can be run directly from in-house laptops and PCs. Th e second isGeoteric StratumTM, a new cloud-based AI software that delivers simple usability and greater detail for fault identifi cation, reservoir compartmentalisation and well trajectory planning. By adding an extra dimension of analysis, the software achieves outstanding results through an intuitive workfl ow, giving the user access to critical information that will inform their exploration and development decisions. Delivery through the cloud allows for scalable compute power appropriate to each task undertaken.

12 GEOExPro October 2020 GEOExPro October 2020 13 Cover Story: Exploration Underexplored African Source Rocks The source possibilities off ered by the Cretaceous and Upper Jurassic in coastal East Africa are promising – but seriously underexplored. NICK CAMERON, GeoInsight Ltd; MIKE REGO, Rego Exploration Ltd

Coastal and off shore East Africa youngest Middle Jurassic and embraces (mid-Aptian). Older Middle Jurassic hosts a variety of long recognised and all but the inception of the separation of and earlier source records are excluded: well described source rocks (Boote Madagascar from Africa by way of the information on them is available from and Matchette-Downes, 2009) but Davie Fracture Zone (DFZ). Emphasis is Boote and Matchette-Downes (2009). considerable additional potential may placed on the Rovuma Delta stradding International Chronostratigraphic be available from Cretaceous and Upper the Tanzania–Mozambique border as Chart age attributions are used (Cohen Jurassic sources. Th ough this interval this is where recent super-giant gas et al., 2013 updated). remains poorly sampled for source discoveries lie and where there is most rocks and no certain oil-to-source tie uncertainty over the hydrocarbon The Mozambique Basin exists, the aggregated indications for the source(s). Loegering and Milkov (2017) suggested development of eff ective sources within Elsewhere, limited East African that both the light oil in the Inhassoro it are suffi cient for this interval to be coastal onshore and nearshore success Field and the gases in Sasol’s fi elds considered as potentially mainstream in terms of commercial hydrocarbon onshore southern Mozambique had as any of the currently recognised ones. discoveries can largely be attributed Cretaceous sources. A weakness in Until an unequivocal oil-to-source tie is to the dearth of published regional this conclusion was that, apart from established, debate regarding the source fi eldwork over the last 30 years, the Palmeira and Sunray wells in the of some discoveries in this region will combined with the lack of wells drilled far south (Coster et al., 1989), quality continue. Successful outcomes to the on other than sparse 2D seismic sources of this age remain to be found ongoing bid rounds in off shore Somalia coverage of variable quality. Th is and an older, presumably richer, source and Mozambique are likely to be lack of exploration success cannot could be more possible (Boote et al., assisted by progress on this debate. therefore be used as a reliable indicator 2017). Reconstructions by Mueller and of the region’s remaining yet-to-be- Jokat (2019) imply that an older source Tectonic Background discovered hydrocarbon potential or is unlikely, as they position ocean Th e investigated succession occupies the distribution and quality of both crust or highly extended continental the pre-Tertiary portion of the Indian mainstream and novel source rocks. crust beneath the region of the fi elds. Ocean drift sequence, which began Figure 2 illustrates the Cretaceous Reeves (2020) shows the Bouvet Plume with the tectonism and transgressions and Upper Jurassic source records and associated magmatism tracking that ended Middle Jurassic carbonate and interpretations deemed credible southwards from 184 Ma following platform deposition above the from the Mozambique Basin, while its fi rst impact in the Beira region, break-up unconformity (Figure 1) Figure 4 shows those from the Somali down the eastern side of what is now during the Bathonian and Bajocian Basin. Both use the drift confi guration the onshore Mozambique Basin and stages (Kapilima, 2003). It includes the released by Reeves (2018) for 120 Ma clearing the present coastline at the

The Makonde escarpment in Tanzania.

14 GEOExPro October 2020 Mike Rego Mike Rego

Figure 1: The Cretaceous to Upper Jurassic potential source interval and its relationship to East Africa’s established play stratigraphy and sources. (BUU: break-up unconformity; RG: regression; TG: transgression). Regressions during the transit of Madagascar occurred at the base of the Cretaceous and within the Aptian. end of the Lower Jurassic. In a personal communication, Colin Reeves (2020) wrote: “there’s hardly a room big enough for the elephant that was the Bouvet Plume so it’s hardly meaningful to pin it down too precisely. My ‘star’ [see Figure 2] is nominally 1,000 km in diameter, but its eff ects were experienced far away”. Figure 2: Confi rmed and interpreted Cretaceous and Upper Jurassic Reeves (2020; 2018) also requires the existence of a sources in the Mozambique Basin. The pale-yellow shaded area is continental fragment beneath the same portion of onshore southern Madagascar’s position at 136 Ma. The two active centres for the Mozambique to ‘best fi t’ the pre-break-up confi guration of Bouvet Plume are positioned using Reeves (2020). Numbers refer to DSDP coreholes. Locations are approximate. Mozambique with Antarctica. Th is fragment, once part of Antarctica, which he names Limpopia, could theoretically host pre-plume sources, but it is diffi cult to envisage how Upper Jurassic sources could be regionally signifi cant in a Limpopian source of this age could survive to contribute southern Mozambique and also in northern South Africa. to Sasol’s fi elds because of the high heat fl ow, hydrothermal Strong support for off shore, Southern Ocean-positioned, circulation and uplift tectonics commonly associated with source intervals of this age is provided by records of large plume heads. It is reasonable therefore to concur with Cretaceous and Upper Jurassic sources at DSDP sites (see Loegering and Milkov and to predict that Cretaceous and Figure 2). Other established examples are the mid-Cretaceous

GEOExPro October 2020 15 Mike Rego Cover Story: Exploration Mike Rego

Figure 3: Vista looking eastwards towards the coast from the crest of the Makonde Plateau escarpment along the valley of the Lukuledi River, along with road-side detail of the escarpment viewed from the west. The shale/ sandstone interbeds are currently interpreted to be Lower Cretaceous in age. Little of this region, which during Lower Cretaceous times was occupied by the Rovuma delta head, has been comprehensively ground mapped.

sources of the offshore south coast basins of South Africa simplest explanation to explain the offshore gas discoveries and the likely Upper Jurassic-sourced oil of the Durban is to link it to a Cretaceous, lean, terrestrial kerogen source Basin (Singh and McLachlan, 2003). Setoyama and Kanungo rock”. Johnstone (2016) suggested Lower Cretaceous might (2020) in their review of the Southern Ocean’s DSDP/ODP be the source as his modelling indicated older sources were results say: “probable high primary productivity in the Early fully matured before the young, gas-bearing structures were Cretaceous in the Southern Ocean”. formed, although contributions from older sources cannot be Using Spectrum’s ‘top soft kick/base hard kick’ seismic discounted. interpretation methodology, Intawong et al. (2019) argued for Older Cretaceous, primarily gas-prone sources are the development of both post- and pre-Turonian oil-prone known from the onshore Rovuma Delta in Mozambique sources in the offshore Angoche Basin (central northern (Edwards, 2005; Hancox et al., 2002) and from the Rufiji Mozambique), finding evidence for spatially associated oil Delta in the Songo Songo Field (e.g Kagya, 2000; Ntomola slicks. and Abrahamsen, 1987). Associated condensates may have originated from a humic marine shale or lacustrine source Southern Somali Basin (Jarvie, 2003). Barremian mixed Type II–III affinity organic Source attributions are complicated in this basin by the matter is identified by Einvit-Heitmann et al. (2016) from the presence of established Middle Jurassic and earlier sources, onshore Mandawa Basin to the south between the Rovuma the complexity of the geology associated with the transit of and Rufiji deltas. Madagascar, and uncertainty offshore relating to younger Released seismic reveals the base Cretaceous surface Tertiary thermal and tectonic events (Sayers, 2017). A further offshore forms a strong unconformity (Sansom, 2018) complication is that the main gas source was not encountered overlain by multiple, eastward-flowing progrades, some in the Rovuma Basin gas discovery wells. Mkuu (2018), of which became the gas field reservoirs. Google Earth however, describes Cenomanian TOCs from the deepwater observations for the region between the Mandawa Basin Zeta-1 well in the Rufiji Basin of just over 3%, associated with and the Rovuma River indicate the basal Cretaceous surface amorphous organic matter at the base of the analysed section. onshore is cutting back westwards across the Jurassic to Pyrolysis records were not included and it is unclear whether overlie Precambrian basement. Little is known about the these kerogens are oil- or gas-prone. Vitrinite reflectance facies of the ensuing thick older Cretaceous cover, but the

values were 1.2–1.6% Ro. Deep section penetrations relief, as currently expressed in the strongly upstanding everywhere are apparently age-limited, with company press escarpment of the Makonde Plateau (Figure 3), suggests releases suggesting the oldest encountered section is no older that this delta head area was a further source of Type than Valanginian. III kerogens of the type encountered just to the south in Basin modelling allows source predictions but as usual northern Mozambique. The overall Somali Basin’s dip in complex settings, multiple possibilities arise (Rego et al., configuration allows Makonde Plateau region sediments to 2019). Fortunately, modern, better quality seismic is exposing be drawn offshore during lowstands or flooding events to the tectonic complexities and volcanicity associated with be incorporated into the overall reservoir succession. This the DFZ (e.g. Sauter et al., 2018), suggesting as the most is analogous to the Indonesian Kutei Basin; here mangrove- likely case the solution that yields the youngest modelled associated kerogens have been drawn down to mature in and, therefore, the least perturbed kitchen. Preferred here is deepwater settings, subsequently expelling hydrocarbons the opinion of Van Itterbeeck et al. (2019) who writes: “the with burial (Ito and Taguchi, 1990).

16 GEOExPro October 2020 Equally little is known about the overall source content of the Lower Cretaceous and Upper Jurassic section of the onshore Rufiji Delta, which had a long and complex Mike Rego history with multiple river mouths. Inland, the source of the Mambakofi-1 gas discovery is rumoured to be the Upper Jurassic (Figure 4). Methane associated with a hot spring further east is of thermal origin with a probable marine source derivation (Kraml et al., 2014). Thick bituminous Lower Cretaceous sandstones were intersected in the nearby Wingayongo borehole (Mbede and Dualeh, 1997), though both bitumen and methane could be products from an older Jurassic, marine source. Oil seeps are present, but too biodegraded to ascertain their source origin (Mpanju and Phelp, 1994).

Northern Somali Basin and Conjugate Margins Effective Cretaceous and Upper Jurassic sources are absent from the coastal zone further north due to the thickness of overlying Lamu Delta sediments until mid-Somalia, where Rodriquez et al. (2019) found seismic indications of oil-prone Cretaceous and Upper Jurassic sources developed in deep water. Further north and north-west Middle East petroleum systems predominate. A deep water seismic profile from offshore Tanzania (Cope, 2000) displays bedding-parallel amplitudes in the interval below the Upper Cretaceous resembling those attributed by Spectrum to source horizons in Somalia. The location of this Figure 4: Confirmed and interpreted Cretaceous and Upper Jurassic line is unknown, but the basin covers the region of the new sources in the Somali Basin. The pale-yellow areas identify Madagascar’s positions at 160 Ma and 136 Ma. Locations are approximate. Tanzanian deepwater gas finds. Should this source prediction 

GEOExPro October 2020 17 Cover Story: Exploration in Somalia result in success, it will rapidly define new areas hybrid petroleum systems, such as the oil seeps found along of Cretaceous and Upper Jurassic source potential. Most the Tanzanian coast from the mouth of the Rovuma River exciting for the region’s oil potential would be the opening of a northwards as far as the Songo Songo Field. This could also new, younger Cretaceous, oil-prone source section should the explain the condensates at Songo Songo. Angoche predictions from the post-Turonian succession be The East Africa-wide spread of potential Lower Cretaceous found to be correct. and Upper Jurassic source possibilities was unexpected. Given the concept that oil-prone source rock deposition Unexpectedly Widespread can be enhanced by the nutrients supplied to sea life from Cretaceous and Upper Jurassic sources are recorded in ash falls during major volcanic episodes (Parker, 2020), the Antarctica, Sri Lanka, and the Seychelles, indicating source explanation may lie in the widespread volcanicity during this rocks of this age to be regionally developed along both time, including large-scale volcanism in the Lower Cretaceous margins during the Cretaceous and Upper Jurassic where and Upper Jurassic during the opening of the Mozambique conditions allow them to accumulate. Collectively, these and Somali basins and along the DFZ (Sauter et al., 2018) and records could outline a northern continuation towards the magmatism augmented in the Mozambique Basin by Africa’s Middle East of the Lower Cretaceous region of “probable high passage northwards across the Bouvet Plume. A DSDP well on primary productivity” in the Southern Ocean (Setoyama and the Mozambique Ridge suggests source rocks associated with Kanungo, 2020). volcanic sediments (Girdley, 1974) – encouraging for Comoros Figures 2 and 4 indicate that most of the gas records exploration as the entire country is underlain by Lower attributed to the Cretaceous and Upper Jurassic are associated Cretaceous ocean crust. with the interaction zone along the DFZ between Africa and Madagascar. Two explanations are possible. The first is that More Investigation Needed Lower Cretaceous and Upper Jurassic gas-prone sources A limitation for this projected source interval is that it will are concentrated here because of hinterland uplift, which lie, except when fully developed and mature, in the nearshore delivered abundant gas-prone kerogens via rejuvenated rivers, and onshore Mozambique and Rufiji basins, and possibly diluting the oil-prone kerogens that would otherwise have additionally the Rovuma Basin, currently deepwater settings, accumulated in a predominantly oil-prone basin (Figure 5). although hydrocarbons may have moved up-dip into shallower The second possibility is that older sourced hydrocarbons waters. This deepwater region may be the true location of the survived the events associated with the transit of Madagascar, Cretaceous charge into Sasol’s fields. Such migration could enabling them to expel gas by pressure release as the pay- also explain the oil shows within the Cretaceous section bearing, delta front collapse structures formed (Rego et al., penetrated by the Ironclad-1 well in the Mozambique portion 2019). This is considered less likely because of the risk of of the Rovuma Basin (Law, 2011). losing earlier generated hydrocarbons to tectonism as the Much remains to be accomplished before the extent DFZ developed. In less active tectonic settings onshore, and quality of the Cretaceous and Upper Jurassic source older established sources could be involved giving rise to systems can be conclusively documented. Particularly important is establishing Figure 5: Villagers collecting fresh water from sandpits dug in the Lukuledi River. The abundance of sand originates from the Makonde Plateau. the source quality of onshore outcrops as this will allow their geochemistry to be related to the rapidly progressing

Mike Rego Mike understanding of the offshore sedimentary fabric. This work has begun in the Tanzanian Mandawa Basin (Einvik- Heitmann, 2016) but large areas of older Cretaceous and Upper Jurassic outcrops remain devoid of source-quality records, while equivalent published records for the offshore wells barely exist.

References and an extended version of this article available online.

18 GEOExPro October 2020 The Kwanza Shelf is witnessing a resurgence in exploration interest with new insights indicating that the potential of this misunderstood hydrocarbon system has been previously underestimated. Historic exploration on the Kwanza Shelf has seen 23 exploration wells drilled, 18 of which were Kwanza Shelf: spudded prior to 1993. Only two exploration wells were drilled on 3D data, with the remainder based on 2D data of various 1980s vintages. Analyses of well results demonstrate that the key elements of a petroleum system are present, with successful reservoirs in both the pre- and New 3D Seismic Imaging post-salt. However, historical wells were unlikely to be optimally positioned due to a limited understanding of the 3D structure obtained from vintage 2D seismic data. Reveals Pre- and Post-Salt Plays In partnership with Agência Nacional de Petróleo, Gás e Biocombustíveis (ANPG), PGS has acquired a new multisensor GeoStreamer survey over the Kwanza Shelf. This new data provides enhanced subsurface illumination through broadband acquisition and the use of modern processing work ows tailored to the unique imaging challenges of shallow water and salt presence. This new broadband 3D multiclient dataset will equip explorers with the tools to identify and unlock the pre- and post-salt plays in this underexplored area of the Angolan o shore. Figure 1: This full-stack PSDM strike line from the Kwanza Shelf survey demonstrates excellent pre- and post-salt resolution. Post-rift stacked turbidite channel and fan systems are well imaged with increased high frequency content revealing detailed depositional features. Complex structures related to halokinesis are unveiled with clear imaging of pre-salt rift basins and basement highs illustrating the prospective potential of the Kwanza Shelf.

20 GEOExPro October 2020 GEOExPro October 2020 22 high where lacustrine carbonates PGS Unlocking Prospectivity on were trapped in a four-way dip- closed structure. Denden-1 found an excellent dolomitised coquina the Kwanza Shelf reservoir exhibiting porosities of up to 15%, proving the pre-salt carbonate play on the shelf. Pre-salt sandstone New data shows that the evolution of the Kwanza Shelf demonstrates key elements of a plays have also been targeted across proli c hydrocarbon system, ready for the 2021 licence round. the shelf. e Flamingo-1 well (1982) encountered oil shows in Cuvo GEORGINA KATZAROS and AVRIL BURRELL, PGS; JEAN AFONSO COLSOUL and NAIRE Formation sandstones con rming the JUDITH RICARDO CAHUMBA QUENGUE, ANPG existence of a good quality pre-salt reservoir sandstone on the shelf. e Kwanza Shelf area has been overlooked in recent is proli c source rock was deposited in sequences exploration cycles with the industry focused on the of  uviatile-lacustrine shales in deep lakes with anoxic Post-rift Transformation Phase: Figure 3: Right: KPSDM dip line with full-stack impedance shown with a 3D seabed surface drape o shore deepwater and ultra-deepwater basin trends. bottom waters and charges both pre- and post-salt Developing Petroleum System above. Left: Seabed surface map view. DHIs in the shallow section show a clear correlation to faults Operators looking to replicate the success of the traps. e syn-rift ended with the widespread deposition Elements. e post-rift shifts from which extend down to the salt weld, indicating a possible hydrocarbon migration route from a Brazilian conjugate margin pre-salt play have made of carbonates and the Loeme Formation salt, which restricted evaporitic facies to open potential syn-rift source rock to post-rift reservoirs. Where faults extend to seabed, pockmarks are also visible following these fault lines. These features are evidence that a working petroleum system a number of successful hydrocarbon discoveries in forms the primary pre-/syn-rift seal (Brown eld and marine deposition resulting in four could be active on the Kwanza Shelf. the equivalent deepwater Kwanza margin. e most Charpentier, 2006). main reservoir units: Albian Pinda notable of these is the Orca  eld, drilled in 2014, which ree main syn-rift/pre-salt reservoir rocks have Formation shelf carbonates; Late Cretaceous Iabe Formation discovered 75m of net oil pay in sag-phase and syn-rift been identi ed. ese are the pre-rift Lucula Formation progradational shallow marine sandstones; Palaeocene/ to su cient depths for hydrocarbon maturation. e reservoirs. is  eld is estimated to be the largest alluvial sandstones, the syn-rift Red Cuvo Formation Eocene Landana Formation sandstones; and Oligocene/ majority of historical wells drilled on the shelf did not drill pre-salt discovery made within the Kwanza Basin to alluvial sandstones and the Grey Cuvo Formation (Chela Miocene Quifangondo Formation sandstones. the pre-salt and of those which did, almost all encountered date. Formation equivalent)  uvial to lacustrine sandstones In the post-salt Albian section, large carbonate rafts are basement after targeting poorly imaged pre-salt highs. With a working petroleum system already proven in and limestones. well imaged and are likely sealed by regional shales. ese e new broadband data images the pre-salt sediments the deepwater pre-salt of the Kwanza Basin, and a licence e Denden-1 well (1983) was one of the earliest wells provide numerous untested leads analogous to the producing and basement structures with improved clarity, de-risking round opening up the underexplored shelf in 2021, a new to make an oil discovery within Grey Cuvo Formation  elds of the Sendji carbonate play in the Lower Congo Basin. exploration of the pre-salt plays in this area. GeoStreamer 3D survey provides an unparalleled insight pre-salt carbonates. e well drilled a tilted fault block Tertiary Landana and Quifangondo Formation The importance of the connection between syn-rift into the prospectivity of the basin, with Figure 2: Top: Full-stack KPSDM seismic dip line. Bottom: Full-stack impedance highlighting sandstones provide promising reservoir targets in stacked source rocks and post-rift reservoirs is illustrated in signi cant untapped potential in the DHIs. This gure highlights post-rift DHIs sitting above a salt weld, indicated by the turbidite and channel sandstones, trapped in structural and Figure 2. This seismic section and trace integration shows pre- and post-rift plays being unveiled. pink dots. Mini-basin touchdown has created a possible pathway for hydrocarbons to stratigraphic traps and sealed by overlying Tertiary shales. a series of post-rift direct hydrocarbon indicators (DHIs) migrate, indicated by the orange arrow, from a syn-rift source into post-rift reservoirs. This clearly located above a syn-rift graben where the post-rift connection may be key for understanding prospectivity across the Kwanza Shelf. Promising Petroleum Systems Overcoming the Challenges of Historical Data mini basin has touched down on a salt weld. This suggests e Kwanza Basin is located o shore e absence of adequate seismic data on the shelf has posed a potential pre-salt source could migrate from the syn- to PGS Angola and forms part of the larger signi cant challenges to exploration, with the imaging of post-rift through the salt weld and reveals the importance West African Aptian salt basin. It complex salt and pre-salt basins being historically poor. of understanding these potential hydrocarbon migration was initiated during Late Jurassic to Mapping of pre-salt grabens and their associated source and pathways. DHIs seen across the survey can be correlated Early Cretaceous rifting of the proto- reservoir potential requires high quality 3D seismic data. to the occurrence of faults, and where these reach the Atlantic and is the conjugate margin is is key in understanding the distribution of petroleum seabed pockmarks are also observed (Figure 3). Shallow to the proli c hydrocarbon-bearing systems and is vital for accurate modelling of hydrocarbon amplitude anomaly DHIs and numerous pockmarks Santos and Campos Basins, o shore migration pathways. e 3D GeoStreamer data acquisition demonstrate that a working petroleum system is active on Brazil. In broad terms, the petroleum on the shelf reveals considerable uplift from vintage data, the Kwanza Shelf. systems of Angola can be split into two greatly improving the understanding of depositional systems main systems: pre- and syn-rift; and and reducing the risks associated with charge, hydrocarbon New Data for 2021 Round post-rift. migration and trap integrity. e shallow water Kwanza Shelf is an exciting underexplored Specialist PGS imaging technologies, including Separated area that can now be evaluated in detail using new Pre- and Syn-rift: Building a Wave eld Imaging (SWIM), Full Wave eld Inversion (FWI) Kwanza survey seismic data. e new data presents Foundation for Hydrocarbon and Q-Velocity Model Building, have been applied to deliver multiple undrilled opportunities and enables improved Potential. e pre-/syn-rift is enhanced resolution imaging of the subsurface. ese understanding of the geological fundamentals, key to characterised by an extensional techniques resolve detailed features in shallow water, which unlocking the prospectivity of the shallow water shelf for the phase which formed a series of horst is not achievable with traditional re ection seismic imaging. upcoming 2021 licence round. and grabens perpendicular to the coastline where mixed  uvial, alluvial Enhanced Imaging Reveals Prospectivity References: and lacustrine facies were deposited. Figure 1 (foldout on previous page) shows a full-stack seismic Brown eld, M. E. and Charpentier, R. R. (2006). Geology is included deposition of the main section from the Kwanza Shelf survey which highlights and Total Petroleum Systems of the West-Central Coastal syn-rift/pre-salt source rock: the previously unseen syn-rift basins where key Bucomazi Province (7203), West Africa. U.S. Geological Survey Bulletin Barremian-aged Bucomazi Formation. Formation source rocks are probably deposited and buried 2207-B.

GEOExPro October 2020 23 24 GEOExPro October 2020 Delivering your product to an audience we know. Technical & geoscience product marketing services in oil, gas & energy.

Find out more at mpmpr.com

Digital & Social Media Management Geo-Product Marketing General Marketing & Admin

GEOExPro October 2020 25 GEO Tourism Sailing Through a Subduction Zone

Floating down the Irrawaddy River is a wonderful way to appreciate both the geological and man- made wonders of Myanmar. LON ABBOTT and TERRI COOK

Highly oblique convergence where the Indian and Eurasian has occurred since the Mesozoic. Th roughout the Early and plates meet has blessed Myanmar with an unusual Middle Cenozoic, today’s central lowlands were home to the geography that underpins the region’s rich history. Th ere Popa volcanic arc and its accompanying forearc and back-arc is no better way to experience this beautiful setting and basins. Th ese were part of an east-dipping subduction zone the country’s spectacular monuments than by fl oating that carried Indian plate oceanic lithosphere beneath Eurasia’s down the Irrawaddy River from the old imperial capital of continental lithosphere. Mandalay to Bagan’s extraordinary temple complex and the Th e margin’s strike-slip component of motion was, until kaleidoscopic splendour of Shwedagon Pagoda in Yangon. the Middle Miocene, distributed across several dextral strike- From its headwaters in the easternmost Himalaya, the slip faults located in today’s eastern Myanmar and Th ailand. Irrawaddy River fl ows 2,200 km to its vast delta on the shores But during the Late Miocene, tectonic adjustments associated of the Andaman Sea. It is along this central artery, which links with the extrusion of South East Asia eastward, out of India’s the cultural centres of Mandalay and Bagan with Yangon, path, focused most of that dextral motion onto the 1,500 modern Myanmar’s largest city, that the region’s culture and km-long Sagaing Fault, which passes through Mandalay. commerce has fl owed since well before its inhabitants were Today it is one of the world’s longest and most active strike- fi rst united under the rule of the Bagan Empire in 1044 C.E. slip faults, accommodating more than half of the right-lateral plate motion between India and Eurasia. Transtension Complex Tectonic Story associated with the fault’s birth fragmented the former arc Th e Irrawaddy is a product of the complex and rapidly complex into a series of north-north-west to south-south-east evolving tectonic confi guration in the borderland between trending, en-echelon sub-basins drained by the newly born the Indian and Eurasian plates, where oblique convergence Irrawaddy River. Shortly after, the stress fi eld at this dynamic

Sunset from the U Bein Bridge in Amarapura.

26 GEOExPro October 2020 Lon Abbott and Terri Cook plate boundary changed again, shifting to transpression. Th is motion inverted the recently formed basins and built folds that form the long, linear hills that parallel the fault, putting the fi nishing touches on the

diverse landscape that today hosts more than Lon Abbott and Terri Cook a hundred ethnic groups as well as thousands of monuments honouring the region’s unparalleled history. We were drawn to visit by tales of Myanmar’s extraordinary Buddhist temples and elaborate pagodas built over many centuries by the Bamar people, the majority ethnic group that has long thrived on the fl at, arable land of the 200 km-wide lowlands known as the Central Myanmar Basin. We started our journey in Mandalay, which hosts many monuments due to its long tenure as the seat of government, and from there sailed down the Irrawaddy to Bagan, where thousands of temples from the Bagan Empire The Irrawaddy River fl ows past one of the many temples on Sagaing Hill near Mandalay. are strewn across the semi-arid plain. Bagan serves as a convenient base to explore not only If you time your visit right, you can also watch the sunset temples but also the former subduction zone’s volcanic arc from the famous U Bein Bridge in nearby Amarapura, which and accretionary wedge; the latter forms the stunning Indo- became the Konbaung Dynasty’s capital in 1783. Th e two Myanmar Ranges that fl ank the Irrawaddy River on the west. cities vied as the region’s capital for the next 74 years until Th ese ranges are home to the Chin ethnic group, many of King Mindon shifted the seat of power to modern Mandalay whose members still practise their traditional lifeways in in 1857. Th e palace was relocated, leaving comparatively little remote hill villages. We completed our Irrawaddy adventure to see at Amarapura except the 1.2 km-long bridge, which is by visiting two especially important Buddhist pilgrimage said to be the world’s oldest and longest one made of teak. sites near Yangon: the world’s largest pagoda, Shwedagon, King Mindon undertook the expensive and arduous and Kyaiktiyo, where a golden boulder remains precariously relocation of his capital city to the base of Mandalay Hill perched on the edge of a cliff , defying the area’s numerous to fulfi l a prophecy that a thriving Buddhist city would be violent earthquakes to knock it down. founded at that spot on the 2400th anniversary of Buddhism’s founding. Today you can tour the royal grounds, ascend Mandalay: Seat of Royalty to the hill’s temple-festooned summit, and visit nearby Th e capital of successive kingdoms that fl ourished along the Kuthodaw Pagoda. Th is claims to be the world’s largest book Irrawaddy River after the fall of the Bagan Empire remained because each of its 729 whitewashed kyauksa gu (stone- within a 20-km radius of modern Mandalay from 1313 C.E. inscription caves) surrounding the central golden stupa until 1885, when the British annexed what they called Burma contains a page of the Tripitaka, the holy canon of Th eravada into the British Empire and moved the capital to Yangon. Buddhism. Today Mandalay, the country’s second city, stands at the While in Mandalay, it is also worth taking a ferry 11 km southern end of an impressively linear 180 km-long reach up the Irrawaddy to Mingun to see the unfi nished hulk of of the Irrawaddy, whose arrow-straight course follows the what would have been the world’s largest stupa as well as Sagaing Fault. the 90-tonne Mingun Bell that was meant to hang in it. Th e Mandalay’s long tenure as the seat of royalty has endowed stupa was begun by King Bodawpaya in 1790, but was left it with an embarrassment of riches, all easily explored on unfi nished when an astrologer foretold that he would die day trips from the city centre. A great place to start is to take as soon as it was completed. Th e massive structure is riven the ferry south across the Myitnge River, a major Irrawaddy by huge cracks formed during the powerful Amarapura tributary, and hop into a horse cart for a leisurely tour of Inwa. earthquake of 1839. Th is rural area was the Kingdom of Ava’s capital city on and Th e long, linear Sagaing Hill rises 240m directly across off for 360 years, starting in 1365 C.E. Repeated destruction the Irrawaddy from Mandalay. Th is large pressure ridge, of the city by earthquakes, eight of which are recorded in developed by transpression along its namesake fault, is an the kingdom’s history books, played an important role in its important religious centre that is adorned with pagodas shifting fortunes. One Inwa highlight is the Bagaya monastery, and monasteries from base to summit. Th e best view of which was originally built in 1593 but burned down in 1821. Sagaing Hill is from the Bagan ferry as it departs Mandalay. Th e reconstructed teak monastery is still used as a place of Immediately downstream of the city’s two bridges, the river prayer for Buddhist monks and other devout locals. bends west, leaving the Sagaing Fault behind it.

GEOExPro October 2020 27 GEO Tourism

Bagan: Plain of 10,000 Temples As the ferry drifts down the Irrawaddy to Bagan, it crosses a remnant of the Miocene tectonic configuration: the old back-arc basin that lay east of the Popa volcanic arc. The pancake-flat Lon Abbott and Terri Cook topography, however, offers no hint of its tectonic Lon Abbott and Terri Cook origin. The highlight of the eight-hour trip is a stop in the pottery-making village of Yandabo and a demonstration of traditional pot throwing and firing. Soon after departing the village, the ferry reaches the confluence with the Chindwin River and a short distance downstream, hills begin to appear in the distance, signalling that you are now crossing the axis of the Popa volcanic arc. The hazy outline of Popa volcano, a 1,518m-high Quaternary cone, is visible 60 km to the south. Geologists disagree whether this Pleistocene volcano, which lies on the Miocene Popa Arc trend, indicates ongoing subduction or is instead associated with Bagan’s temples are especially striking just before sunset. local extension. As the boat continues westward, the river crosses into the forearc basin before docking at Nyaung-U, Bagan’s main town. A worthwhile day trip is to Popa volcano, the largest This UNESCO World Heritage Site was the seat of the feature in the Popa volcanic arc, about 50 km south-east Bagan Empire from 1044–1287 C.E. During those years, of Bagan. We spent a delightful day hiking through the devout kings and noblemen constructed more than 10,000 rainforest, ascending 600m from the Mount Popa Resort to shrines, from the 66m-high Thatbyinnnyu Temple, built by the summit and sharing the trail with Myanmarese school King Sithu I in 1150 C.E., to small personal shrines funded groups and a team of mountain bikers from Yangon. We also by royal officials and wealthy merchants. Reserve at least two toured the Taung Kalat, a precipitous volcanic plug crowned days with a guide to explore some of the many highlights, by a Buddhist monastery that is reached by walking (barefoot, which range from neglected ruins to carefully maintained as always in Buddhist shrines) up 777 stairs. shrines still visited by thousands of believers each year. Another highlight is Shwezigon, a miniature version of Crest of the Indo-Burman Ranges Yangon’s gold-leafed Shwedagon Pagoda, as well as sunset Bagan, sitting as it does in the forearc basin, is the staging area viewing of the temples aflame in the last orange rays of the for a trip up into the Indo-Myanmar Ranges, the homeland day. One of our favourite sites was the 1113 C.E. Mayazedi of the Chin people and the subduction zone’s accretionary Quadrilingual Stone. Housed in the Mayazedi Pagoda, it has wedge, which was uplifted during the Miocene. One not-to- the same text inscribed in four different languages: Pali, Pyu, be-missed sight there is Mount Victoria, the tallest peak in the Mon, and Myanmar, and its significance for translating Pali southern Indo-Myanmar Ranges at 3,063m. Tour agencies in and Pyu is comparable to that of Egypt’s famous Rosetta Stone. Bagan can arrange a three-day excursion that allows enough time to make the two to three-hour round-trip The Buddhist monastery and temple complex of Taung Kalat is perched atop a volcanic plug at Mt. Popa. hike through blooming rhododendron trees to the mist-shrouded summit. While there, we shared the mountain with several enthusiastic groups of shutter-snapping Myanmarese Luis Valiente Luis students who had come to see a wild side of Myanmar that was utterly foreign to them. Our trip also included visits to remote villages, where we saw older Chin women with faces scarred by elaborate tattoos and people still living in ways that have barely changed since pre-colonial times. Our friendly Chin driver, who knew the roads and people intimately, took us to a remarkable, out-of-the-way museum of Chin culture in the hill town of Mindat. There the proprietor showed us the accoutrements of Chin warriors, played a song on a traditional nose flute, and toured us through his extensive collection of artefacts spanning the Indo-

28 GEOExPro October 2020 Myanmar Range’s human history and even pre-history, including mammoth teeth discovered in the region.

Yangon: Two Extraordinary Pagodas One can take a boat all the way from Bagan to Yangon, but since this takes several days, we chose a one-hour Lon Abbott and Terri Cook flight instead and settled into our hotel, whose rooftop restaurant had up-close views of 112m-tall Shwedagon Pagoda’s gleaming golden stupa. Located just a few blocks from the hotel, Myanmar’s most sacred Buddhist site enshrines a variety of Buddha relicts. Thousands of devout pilgrims dressed in their finest attire circumambulate the stupa every day, praying in their favourite spots along the route. Accustomed though we were to the colourful and ornate nature of Myanmar’s shrines, Shwedagon’s exuberant architecture, adorned with gold, glass tiles, mirrors, and A Chin couple from Kyar Hto village in the Indo-Myanmar range. flashing LED lights, was a sensory overload. The pagoda’s central stupa has so much gold leaf (at least an estimated nine tonnes) that during British rule it was said that Shwedagon possessed more gold than the Bank of England! As if that was not enough, the spire is encrusted with 5,500 diamonds and 2,300 rubies. Milling with the throngs of Buddhist pilgrims, slowly circling clockwise around the Lon Abbott and Terri Cook sparkling pagoda, is an unforgettable experience. We rounded out our trip by travelling 200 km east of Yangon, crossing the Sagaing Fault en route, to Kyaiktiyo (Golden Rock) Pagoda, a small (7.3m) pagoda built atop a massive granite boulder perched at the brink of a cliff. The people of Myanmar are acutely aware of earthquake hazard, so the improbability of this boulder precariously perched at the edge of the abyss is not lost on them. Legend holds that the rock is held in place by a strand of Buddha’s hair, which makes it a major pilgrimage site; another fascinating opportunity to explore the stunning mix of beautiful scenery and ancient and modern culture that characterises the Irrawaddy corridor. Kyaiktiyo, the Golden Rock pagoda, sits atop a precariously perched boulder.

GEOExPro October 2020 29 Technology Explained

MARK DAVIES, and GARY BARNES, Egypt’s Buried Secrets AustinBridgeporth The fi rst outing of the world’s most sophisticated airborne gravity gradiometer has already yielded fascinating insights into the unexplored Egyptian subsurface.

In today’s rich smörgåsbord of ocean and after declassifi cation were the survey area is three quarters the exploration technology, we rarely get modifi ed to acquire data in the more size of Florida; and thirdly, acquisition to witness a signifi cant leap forward dynamic airborne environment. With was to take no more than ten weeks. in instrumentation advancement. the exception of some minor upgrades Quite the challenge for the fi rst sortie Nonetheless, this is exactly what and construction of a partial tensor into for the Lockheed Martin achieved in system (rather than a truly full tensor instrument; a challenge the eFTG developing their newest state-of-the-art system), little has changed over a overcame, surpassing all expectations. gravity imaging system, aptly called quarter of a century. Th e Ganope Petroleum Company the ‘Enhanced’ Full Tensor Gravity However, in August 2020, after manages and supervises all upstream Gradiometer (or eFTG for short). fi ve years of development and testing, and downstream oil and gas activities Some explorationists will be forgiven the eFTG instrument was exclusively in Egypt between latitudes 28° and for thinking that gravity imaging has released to AustinBridgeporth and 22°N. Th e Western Desert is a vast been around ‘almost’ as long as some mobilised to acquire data over an kaleidoscope of rolling terrain and of the ancient antiquities discovered underexplored region of the Egyptian sand dunes punctuated by rugged by Howard Carter et al. So, what could Western Desert (Figure 1). Th is new ridges and a large north–south possibly have changed so radically to instrument, with a reported fourfold trending valley (Figure 1). Exploration revolutionise our world of exploration, improvement in signal to noise ratio in this remote landscape dates back and more importantly, when do we on its closest competitor (i.e. the over 50 years, but little has been get to see evidence that warrants such Lockheed Martin built FTG; note no undertaken of late, primarily because superlatives. Th e answer is: a lot has ‘e’), was tasked with acquiring gravity three wells were drilled into shallow changed and the data is available now! gradiometry data for a TGS-led multi- basement, condemning the area to client programme, specifi cally designed the ‘not prospective’ bin. Th is analysis A Challenging Environment to unlock the treasures that exist was reinforced by several incorrect Lockheed Martin are the only beneath 120,000 km2 of the Western publications showing a shallow basement manufacturer to have successfully built Desert. On the face of it, a routine to extend over much of Ganope’s and commercialised full and partial survey until you factor in fi rstly, that Western Desert area. A particular blow tensor gravity gradiometers. Based on acquisition would take place in summer was the West Kom Ombo (WKO) well, 1970s cold war technology, they were where the temperatures exceed 45°C, sited to detect the western extent of the originally designed to operate in the generating fi erce turbulence; secondly, Kom Ombo Basin, a proven hydrocarbon Figure 1: Horus-1 eFTG survey area over the Western Dessert and the subsequent discovery of new basin with production to the east. Th e rift basins. eFTG multi-client survey was to be the fi rst high resolution dataset to be fl own over this frontier area.

How Did eFTG Perform? Fast-tracked processing results are already available and the survey is expected to complete by the end of September. Although AustinBridgeporth and TGS have only just started preliminary processing and interpretation, the results are already exceeding expectations. Th e team have identifi ed pan-African and Arabian shield trends, and the uplift from the legacy gravity data to the eFTG data is quite remarkable even when looking at imagery on an 8-km line spacing (Figure 2). Th e images will only get better as we move from 8-km to 2-km line spacing

AustinBridgeporth and the processing is refi ned.

30 GEOExPro October 2020 But what about the all-important with turbulence whilst prospectivity of the upper Western eFTG noise is more linear. Desert? The three wells would never Figure 3b gives the ratio have been sited had eFTG data been of these trends and shows available at that time, as they are located the noise improvement on positive high anomalies indicative of factor of the eFTG over this shallow basement. Even WKO, thought range of turbulence. The to sit in the basin proper, was drilled minimum of this ratio for into a shallow structure. However, what data acquired in reasonable is far more exciting is the discovery of conditions is approximately a previously unknown rifted section three and close to the beneath a carbonate/marl platform. theoretical prediction The rift is about 75 km to the east of based on just the scaled- the Qusur-1 and Bulaq-1 wells, which up size of the instrument. are located in the modern-day valley, More unexpected, however, assumed to be the surface manifestation is the significant relative of the subsurface rifted section. improvement of the eFTG Three wells, three mistakes, data for higher levels of and three decades of exploration turbulence, where the noise abandonment for the Ganope Western ratio approaches a factor Desert region. of 8. However, FTG data would rarely be collected eFTG in the Exploration Toolkit in levels of turbulence AustinBridgeporth It is clear that the eFTG is adding greater than 0.9 ms-2 due Figure 2: Legacy terrain corrected (TC) gravity vs, Horus-1 eFTG value to the exploration workflow at to the known deterioration TC gravity data. The eFTG highlights poor well locations and discovers new rift basins (R1,2,3). every stage, from regional mapping of the data quality. The and de-risking acreage to enabling more modest increase in noise with accurate design and implementation turbulence seen in the eFTG data has, need to be nine-times tighter to reduce of future seismic surveys. The data is however, allowed data to be collected the noise to the same level as seen in the also providing constraint to processing in much higher levels of turbulence, eFTG. Since survey cost increases with and interpretation of seismic data that leading to exceptional productivity rates the line kilometres flown, the eFTG is is rendered opaque by the presence in excess of 1,000 km (accepted) per therefore capable of imaging targets of salts, carbonates and volcanics. flight. that would have been prohibitively Future 3D seismic surveys are already Over typical survey turbulence levels, expensive to survey with the previous being planned with well siting, hazard the noise offered by the eFTG is three instrumentation. Simply put, Horus-1 detection and reservoir mapping all to five times lower than the FTG – and and the eFTG instrument have exceeded derived from the acquired eFTG data. a three-times reduction in noise is all expectations. In isolation, the imagery is equivalent to a nine-times increase in impressive, especially given the efficiency. Consider an anomaly whose References available online. regional survey's wide line spacing. gravity signal amplitude places it at As we move to a 2-km footprint, more the detection threshold of eFTG noise. The Authors would like to thank Ganope details will emerge from the geological To see this anomaly within FTG noise and TGS for allowing publication of understanding. However, away from levels, the survey line spacing would Horus-1 survey data. the unfolding geological story, what Figure 3: (a) Noise level versus turbulence level for FTG (dots) and eFTG (stars); (b) Ratio of FTG and has truly impressed the team is the eFTG noise levels over a range of turbulence. Dashed ends of lines represent sections of extrapolation. advancement in performance of Lockheed’s latest system. a) b) Now that eFTG has been in airborne operation for the first time, it is possible to draw realistic comparisons between it and older FTG instruments under actual survey conditions. Figure 3a shows the noise levels for several survey lines from FTG and eFTG surveys, both acquired in a range of turbulence levels. The solid lines represent visually fitted trend curves and suggest that FTG noise varies roughly quadratically AustinBridgeporth AustinBridgeporth

GEOExPro October 2020 31 Energy Transition Hydrogen and CCS in Future

Energy CORIN TAYLOR, DNV GL What is the role of hydrogen together with carbon capture and storage in enabling a net zero carbon energy system?

Hydrogen as a clean energy source and carrier has rapidly but increasingly with reference to the associated carbon moved centre stage in recent years. It is estimated to comprise footprint. Most of the hydrogen made today is used in the 75% of all mass in the universe and has the highest chemical petroleum refi ning process or as one of the main chemical energy content, by mass, of all gaseous and liquid fuels. It is ingredients in fertilisers. abundant everywhere on Earth and there are a number of At the moment, the most common method of making ways in which hydrogen can be both produced and used with hydrogen is by using natural gas and a technique called a low carbon footprint, with few detrimental environmental steam methane reformation. Th is combines methane from consequences such as pollution or climate warming gas with water at very high temperatures (approximately emissions. 900°C) to produce a mix of carbon monoxide, carbon dioxide However, on Earth hydrogen occurs naturally only as a and hydrogen. By controlling the amount of air, water and compound, predominantly in water, but also in hydrocarbons, methane in the reaction, it is possible to change the amount so in order to be used it needs to be released from its bonds of energy required and the waste gases produced. Hydrogen with other chemical elements like oxygen and carbon. Th is produced in this manner has a carbon footprint of about requires energy – and how to do that safely, in a cost-eff ective 10–12 kg CO₂e per kilogram of hydrogen, unless carbon way that does not increase CO₂ and other emissions, is the capture and storage (CCS) is used to dispose of the CO₂. crux of the issue. Another method of obtaining hydrogen is to use electricity to split water into hydrogen and oxygen through electrolysis, Yellow, Blue and Green the water typically heated to between 20° and 100°C. Th is Hydrogen can be produced in a variety of ways and from a technique is capable of producing hydrogen at a range of number of sources, dependent partly on the fi nal application, scales and uses, from small electric car refuelling stations to

A visualisation of a coal power plant equipped with a CO₂ capture facility. DNV GL DNV

32 GEOExPro October 2020 DNV GL

Main hydrogen production options. major offshore electrolysis projects. is used for hydrogen produced through Obviously, the most important factor electrolysis that has the same level of Explaining Acronyms from the point of view of CO₂ emissions emissions. The phrase ‘blue’ hydrogen A greenhouse gas (GHG) is any in this case is how the electricity used describes hydrogen produced from gas in the atmosphere which in the procedure is made; only if the fossil fuels when CCS is used, although absorbs and re‐emits heat, electricity has a carbon footprint of not applicable when the CO₂ is used and thereby keeps the planet’s less than 250 kg CO₂e/MWh (roughly for enhanced oil recovery, and ‘yellow’ atmosphere warmer than it half the emission intensity of a modern (sometimes ‘grey’) is used for hydrogen otherwise would be. The main combined cycle natural gas-fired power produced from fossil fuels when CO₂ is GHGs in the Earth’s atmosphere plant) is hydrogen from electrolysis released into the atmosphere. are water vapour, carbon dioxide less emissions-intensive than hydrogen (CO₂), methane (CH₄), nitrous production from natural gas. And How Different Sectors Use Hydrogen oxide (N₂O) and ozone. in order to be genuinely low carbon, Blue hydrogen is currently estimated Carbon dioxide equivalent hydrogen from electrolysis needs to use to be the cheapest option for producing (CO₂e) is a term for describing renewable or nuclear electricity. hydrogen gas in a low-carbon way – but different greenhouse gases in a Coal can also be used as a hydrogen what are the sectors in which this can common unit. For any quantity source using a process called be useful towards zero carbon? The and type of greenhouse gas, CO₂e gasification, by which a syngas is answer is that it has potential in all signifies the amount of CO₂ which created using coal and water at high areas. would have the equivalent global temperatures (>750°C). The coal is In manufacturing, for example, in warming impact. A quantity of used to provide the heat needed for order to reach net zero, every furnace GHG can be expressed as CO₂e the reaction to work, but this process and kiln will need to switch to clean by multiplying the amount of obviously produces large quantities of electricity, hydrogen or bio sources and the GHG by its global warming

CO₂, so CCS is again needed to reduce the CO₂ emitted will need to be captured potential (GWP) e.g. if 1 kg of its carbon footprint. from all industrial facilities. To achieve methane is emitted, this can Hydrogen can also be made this, hydrogen could replace gas in be expressed as 25 kg of CO₂e through heating biomass and mixing industrial processes requiring heating (1 kg CH₄ * 25 = 25 kg CO₂e). it with steam and oxygen to produce and as feedstock, and several projects are CO₂e is a very useful term for a hydrogen without combustion. If the underway to investigate the possibilities. number of reasons as it allows heat source is ‘green’ and the process One such is HYBRIT, a Swedish initiative ‘bundles’ of greenhouse gases to produces emissions of less than investigating using hydrogen produced be expressed as a single number; 8 kg CO₂e/kgH₂ then the resultant by electrolysis of water using fossil-free and it also allows different hydrogen is also ‘green’; the same term electricity instead of coking coal in the bundles of GHGs to be easily compared (in terms of their total Blue hydrogen will pave the way. global warming impact). However, when comparing CO₂e totals it is

DNV GL important to know that the same GHGs are included in the totals being compared, in order to be sure that like‐for‐like comparisons can be made. Ecometrica.com

GEOExPro October 2020 33 Energy Transition

forward. China is actively investigating the use of hydrogen-

DNV GL fuelled buses and there is also research in progress as to the viability of using hydrogen as a fuel for ships.

Investment Required For the examples above to be green, however, the source electricity must be carbon net zero. In the future, solar and wind will be providing increasing amounts of power, but hydrogen also has a part to play; for example, when there is excess of power from renewables, the extra can be used to produce hydrogen, which can in turn provide power when the intermittent sources are unavailable. DNV GL predicts that oil demand has already peaked and gas demand will do so in the early 2030s, but by 2050 half of the world’s energy will still be sourced from hydrocarbons, particularly gas. Since fossil fuels are therefore expected to HyStreet: An experiment in using hydrogen in the home. remain in the energy mix for many years to come, increased use of CCS in power supply, directly on industrial emissions, and to steel-making process, which is one of the highest CO₂-emitting decarbonise hydrogen production is vital to decrease emissions. industries, accounting for up to 7% of global emissions. The International Energy Agency Sustainable Development In many cases, however, the process to convert existing Scenario 2050 suggests that 2.8 billion tonnes of CO₂ will need industrial technologies to enable them to be powered by to be captured per annum, which would require 1,800 CCS hydrogen is difficult, so the most appropriate route to reduce plants worldwide, each capturing 1.5 million tonnes per annum. emissions in the short term is to use CCS. That is an ambitious and expensive proposition; how could Buildings account for about a third of global final energy such a major investment be paid for? It will need some assistance use and one fifth of GHG emissions, but few are heated – after all, wind and solar have benefitted from at least 15 years or cooled in a low carbon way. Many homes use natural of price support, with different mechanisms used in different gas for heating and cooking, and it is possible to blend up countries. Carbon pricing will play a part, although that will to 20% hydrogen into the domestic input without having need some intergovernmental cooperation to avoid polluting to alter appliances – or 100% hydrogen if the appliances operations just moving from a high to a low carbon pricing zone. are changed. In the north of England the H21 project is The cost of wind and solar technologies is falling fast, investigating ways to convert the gas supply of a number driven by economies of scale, technological progress, of cities from natural gas to hydrogen, which will require including bigger turbines and floating operations, and reduced replacing all gas appliances in commercial and residential cost of capital as investors see that these technologies can building; a major undertaking, but one which was done work and embrace them as no longer risky. Hydrogen and in the previous century to avail of natural, rather than CCS are where wind and solar were 15 years ago, and there synthetic gas. The hydrogen would be supplied from is no reason why they should not make similar progress. reforming natural gas, so CCS will be needed to deal with Introducing financial mechanisms to support deployment is the resultant CO₂. key to the development of this sector. Due to its combustibility, there are some questions over the safety of hydrogen in the home. To analyse these References available online. issues DNV GL has built a small street of terraced houses Solar Hydrogen Station: The station is the first of its kind using solar to establish if it is technically possible, safe and convenient energy from a solar PV array to make renewable hydrogen on-site and to replace natural gas with hydrogen in residential and is the second of three UK stations to be deployed as part of the pan- commercial buildings and gas appliances. Among other European HyFive Project. things, the company is checking what happens if there is a ITM hydrogen gas leak either inside or outside the home, using some 75 sensors fitted in the house to detect and measure hydrogen concentrations at various heights in every room. While battery electric vehicles are now a familiar sight on our roads, hydrogen fuel cell electric vehicles are less common. Battery-powered vehicles are cheaper to fuel than hydrogen equivalents (at present), but take longer to charge and have a shorter range, so it is expected that there will be greater uptake for hydrogen-fuelled systems in the heavy truck and bus sectors. Since heavy goods vehicles account for 16% of transport CO₂ emissions in the UK, even though they represent only 2% of vehicles, this would be an important step

34 GEOExPro October 2020 GEOExPro October 2020 35 Hot Spot Brought to you in association with NVentures. The Hotspot That Keeps On Giving ROG HARDY and PETER ELLIOTT, More success in Guyana–Suriname – and patterns are emerging. NVentures Ltd

Building on the sterling success at Kwaskwasi-1 in Suriname announced an astounding 18 discoveries and only two dry Block 58 (GEO ExPro Vol. 17, No. 4) Apache are looking to go holes. In this clastic channel-fan stratigraphic trap complex four for four – and extend this exciting trend to the south- some wells designated exploratory might turn out to be east with Keskesi East-1. Along trend to the north-west on linked, but all seven appraisal wells have been successful, so the Guyana Stabroek Block, ExxonMobil have reported their this is an extraordinary feat of AVO calibration – 27 of 29 18th discovery with the Redtail well, logging 70m light oil in wells have logged pay in this emerging basin. sands with the usual high permeability, while appraisal well Th e successful wells have from 18m to 93m net pay from Yellowtail-2 found a new zone logging 21m pay. In addition, multiple zones in the Upper Cretaceous, averaging 51m. Th e Shell are re-entering the action by acquiring the Suriname oil is low-sulphur with APIs in the low 30°s, except Haimara- interests of Kosmos. 1 on the south-east end of the trend, which encountered gas condensate. No fl ow rates are noted, but Hess cites Trends by the Numbers permeabilities ranging up to 4 Darcys and porosities While operators are understandably keeping logs and seismic commonly over 30%. Th e group also made the Ranger close to their chest, numerous press releases allow us to discovery in carbonates, which has now been successfully characterise developments since the original Liza-1 discovery delineated. in May 2015. Here are some takeaways: Estimates of recoverable hydrocarbons discovered is now On the Stabroek Block the ExxonMobil group, which over 8 Bboe, increasing with E&A drilling from an initial includes Hess and CNOOC, have drilled 29 exploration 1.4 Bboe. Given these factors, Hess touts a world-beating and appraisal wells plus Liza development wells in between breakeven oil price of $25/bo for Liza Phase 2, or $7boe 1,150 and 2,200m of water about 180 km off shore in benign development costs, resulting in payback in fi ve years for each sea conditions. TDs have ranged from 4,225m to 6,450m, development at a $45/bo price. Th e Liza Phase 1 development averaging about 5,450m. Excluding a few wells that had went online last December, just 55 months after discovery extensive coring and logging, we estimate it takes 20 to – unheard of for a province-opening deepwater FPSO 100 days to reach TD, averaging about 50 days, although development. Th e group hopes to reach 750,000 bopd with Hess reports that development wells are taking less than 30 fi ve to six FPSOs by 2026, which would be another a world- days, and now cost less than $60 million. ExxonMobil have class performance. NVentures

Discovered fi elds and prospects (purple) off shore Guyana and Suriname. Black triangles represent ‘wells to watch’ due to be drilled in the near future.

36 GEOExPro October 2020 Apache’s high-profile success along trend on adjacent Block 58 in Suriname is in similar water depth, but TDs are a little deeper, from 6,300m to 6,645m, taking an average of 82 days to reach TD. Pay zones are presumably correlative to Stabroek in the Upper Cretaceous, somewhat evenly distributed in the Campanian and Santonian, but deeper and containing light volatile oil and gas condensate. API gravities range from 34° to 43° and gas–oil ratios from 967 to 1,178. The 278m net pay in the Kwaskwasi-1 is high for the trend, and the three wells average 160m of pay, compared to the 51m for Stabroek. At the end of the day it will be really interesting to see which block will have the best returns. Apache is logging more pay, but the zones are somewhat deeper and under higher pressure, so the wells are taking more time to drill, hence presumably more expensive. Furthermore, can Apache and Total reach the Stabroek initial development phases. Turonian on Block 58 to test that play?

Upcoming Action Both wells drilling now – ExxonMobil’s Tanager-1 (on a new block, Kaieteur) and Apache’s Keskesi-1 – can potentially extend the trend in both directions. An upcoming well by could further extend the trend to the south-east in Suriname. Also, BHP recently spudded Broadside-1 in Trinidadian Block TTDAA 3, outboard of their recent gas success in that country, targeting deeper oil zones that may be part of the same petroleum system as on Stabroek. ExxonMobil’s Ranger discovery is midway between Broadside and Keskesi. The main challenge for exploration teams in a number of companies is to now prioritise their prospect Cumulative wells drilled in the Stabroek Block, Guyana and recoverable inventories with this growing database. resource growth (Bboe) between 2015 and 2020.

GEOExPro October 2020 37 GEO Physics CSEM: Back from the Brink Controlled Source ElectroMagnetic is a proven technique that has a strong future, especially when seismic data alone cannot provide a satisfactory answer. RICHARD COOPER and LUCY MACGREGOR, OFG Multiphysics

Past, Present and Future the crust and mantle and were deployed a few years, both emgs and OHM IPO’d Controlled Source ElectroMagnetic around the globe. Exxon was the fi rst oil for stellar valuations (approximately (CSEM) methods have been company to see the promise of CSEM US$1.5 billion and US$300 million commercially available to the upstream methods for hydrocarbon exploration respectively) and AGO was sold oil and gas industry for approximately and fi led a patent for the use of this to Schlumberger (WesternGeco). 20 years. Despite a promising start, the technology in oil and gas in 1981. Meanwhile PGS acquired the University method has never been widely used and November 2000 marks the start of Edinburgh spin-out MTEM, along its popularity has waxed and waned in of the modern era of CSEM. Statoil with its marine electromagnetic (EM) lockstep with the ups and downs of the (now ) funded a survey in technology, and developed this into a oil industry. For this the CSEM industry Angola, employing receivers from new CSEM system in which both the itself must bear some responsibility. Scripps (now under the direction of source and receivers are towed behind Th ere are, however, signs of renewed Professor Steve Constable) and using the survey vessel in a confi guration interest in CSEM methods even in an active CSEM source developed by similar to a standard seismic these diffi cult times. As CSEM usage the team at Cambridge University acquisition. Th is innovation, one of increases again it is important to in the UK, led by Professor Martin the most signifi cant since Chip Cox’s understand the lessons from the past to Sinha and Dr Lucy MacGregor. Also original surveys of the 1970s and 80s, ensure a more sustainable future for the onboard were geoscientists from Statoil, allows rapid and effi cient acquisition of technology and to prevent a repeat of including Dr Svein Ellingsrud. Th is high quality marine CSEM data. wasted eff ort and money. survey attempted to ‘locate’ a known hydrocarbon reservoir, which it duly What Went Wrong? Looking at the Past did, leading to a rapid expansion of the Th is activity should have been the Th e origins of marine CSEM can be industry. start of a golden age of marine CSEM traced back to the Scripps Institution Almost immediately following the – but alas not. Within a few years, in California, where Professor Chip Angolan project the Norwegian team Schlumberger had shut down their Cox and his team developed the fi rst founded emgs, the Cambridge team CSEM business, emgs saw its market marine source and receiver systems in formed Off shore Hydrocarbon Mapping capitalisation collapse, and OHM’s the 1970s. Th ese tools were developed (OHM) and Scripps collaborated with acquisition capability was sold off to investigate volcanic fl uid systems in AOA geophysics to form AGO. Within to emgs, whilst OHM’s analysis and

Figure 1: CSEM brings most value when closely integrated with seismic. This example from the Barents Sea (courtesy PGS) demonstrates the improved resistivity resolution that can be achieved by conditioning EM inversion with seismic structure. Multiphysics workfl ows can then be applied to determine rock and fl uid properties. CSEM

38 GEOExPro October 2020 CSEM

Figure 2: Three approaches to marine CSEM acquisition are now available. Left: Seafloor deployed receivers and a deep-towed EM source is the ‘classic’ approach to acquiring data. Centre: The towed streamer EM system allows rapid acquisition of data since both source and receivers are towed behind the survey vessel. It is applicable in water depths less than about 500m. Right: The vertical dipole system uses seafloor deployed receivers and stationary transmission stations. Figure redrawn from MacGregor and Tomlinson, 2014, Interpretation, 2, AH13–AH32.

interpretation capabilities were merged The marine seismic acquisition What Have We Learnt? with Rock Solid Images. business is now a shadow of its CSEM is not a universal tool. If you can What went wrong? A number of former self. To a large extent the answer your exploration and production factors caused the erratic commercial CSEM industry has been affected by questions using seismic, then it is performance of CSEM in upstream oil exactly the same challenges of low probably not necessary to consider and gas. It appears that CSEM was “over service demand seen by the seismic adding CSEM into the interpretation promised and underdelivered”– never industry. There have only ever been mix. However, we all know of many a good recipe for success. The method a small number of CSEM acquisition cases when seismic data alone is was sold as a magic bullet, even as a contractors to the oil and gas industry incapable of resolving interpretation replacement for seismic (hence the initial and a variety of acquisition strategies risk associated with lithology or huge valuations). In addition, CSEM have been applied (Figure 2), each with hydrocarbon charge. In such cases, applications to reservoir mapping were at pros and cons which must be weighed the addition of CSEM data using the start of their development. Expertise up when designing an acquisition carefully constructed multiphysics resided in only a few commercial campaign. The remaining contractors workflows may substantially reduce this organisations and universities and little include: interpretation risk. or no commercial software was available • emgs: Though their vessels are The importance of pre-survey for processing and interpreting CSEM cold-stacked, emgs retains the modelling cannot be overstated. data. Patent wars also played a part. world’s largest fleet of seafloor CSEM data are under-sampled The major players embarked on a series deployed CSEM receivers and owns both horizontally and vertically, of tit-for-tat patent wars, which proved a sophisticated source technology and the technique works best when enormously costly and confused and and also algorithms for inversion and focused to map the target of interest. distracted clients – enriching no one but interpretation. It is important to understand the the patent attorneys. • Allton (formerly Petromarker). Allton background geology so we can However, perhaps the biggest promotes an alternative seabed nodal determine, ahead of the survey, mistake was an unwillingness to accept system, using vertical source and whether we will be able to detect and that CSEM works best when integrated receivers. interpret the resistivity features of with seismic. In the early days of CSEM • Ocean Floor Geophysics. OFG has interest and how to optimise the survey adoption, data were often analysed a long track-record in providing parameters. in isolation, leading to ambiguous a basket of subsea geophysical Processing, interpretation and the results. On survey after survey, careful measurements including towed, integration of seismic data all matter. analysis has highlighted the value of nodal and AUV-mounted marine EM The CSEM industry has developed the close integration of CSEM and for mapping hydrates and seafloor sophisticated products such as seismic (Figure 1). This has not been massive sulphides. In 2020, OFG anisotropic 3D inversion and seismic/ well communicated by the providers of acquired the rights to the PGS towed- CSEM joint-inversion which have CSEM data. streamer CSEM acquisition system, dramatically improved the quality and related interpretation tools. and value of the information obtained The Present On the client side, CSEM surveys are from CSEM data. These work best Yet despite these both self-created under consideration in a number of when combined with information and existential challenges, the CSEM areas including Australia’s North West from seismic data over the same area. industry remains intact: the lights are Shelf, South East Asia, Southern Africa, It is important to realise that success still on, even if dimmer than we would the Mediterranean and the Gulf of requires a commitment to doing a like. What is the present state of play? Mexico. proper analysis.

GEOExPro October 2020 39 GEO Physics

Future Outlook characteristics of the reservoir and its seismic in much the same way as a Let’s go back to first principles. When a surroundings. petrophysicist would combine sonic well is drilled and logged, we investigate When it comes to surface remote and resistivity data from well logs. the borehole using a variety of different sensing methods, the tool of choice CSEM-derived resistivity data is physical measurements including both is an acoustic method: seismic. “just another attribute” and can be acoustic and electrical tools (Figure 3). However, we now have an option to used with seismic attributes (such Indeed, the sonic and resistivity logs acquire CSEM data which, if properly as AVO and impedance attributes) are two of the most important tools acquired and processed, yields a to constrain an interpretation of the a petrophysicist will look to in order complementary resistivity section. saturation and pay of a target horizon. to understand the lithology and fluid This can be interpreted alongside The caveats remain; there is no magic Figure 3: Well log analysis is inherently a multiphysics process. Measurements of a range of physical properties are bullet, and interpretation integrated in and rock physics workflows in order to interpret the lithology and fluid properties of the uncertainties will always subsurface. The advent of EM methods allows a similar multiphysics approach to be applied to geophysical data, exist (Figure 3). leading to more robust interpretations of the subsurface. Further details of the example shown can be found in Alvarez et al., 2017, Interpretation, 5, SE43–SE60. We need to move away from the phrase “I don’t believe in CSEM”. CSEM is not a belief system or a religion, it is a scientific method built upon Maxwell’s equations, which underpin most of the technology we use in our modern world. Like any tool, it can be misused, but the CSEM industry is now capable of delivering robust resistivity data for a range of oilfield applications. CSEM data is real data; it is different from and complementary to seismic data and can add significant value. Looking to the future, CSEM is a proven technology that should be routinely considered to help solve certain classes of exploration and production challenges, especially when seismic data alone cannot provide a satisfactory answer. In areas where seismic data already exists, CSEM data can be added to provide additional information that helps define the presence and quality of hydrocarbons. In such areas, CSEM and legacy seismic data may be more cost effective than new seismic data acquisition, and may offer a lower environmental footprint. Here’s to another 20 CCSM: Data courtesy PGS years of CSEM!

40 GEOExPro October 2020 The licence round has been announced, the petroleum law rati ed, and geoscientists are pouring over the seismic. Are we nally set to see the undoubted exploration opportunities of one of the Why Exploration world’s last true hydrocarbon frontiers nally realised? The seismic below is a dip line from southern o shore Somalia showing fold and thrust belt with mainly Cretaceous deltaic and deepwater sediments involved in the thrusting. Good quality, Late Cretaceous reservoirs are expected, with the sands having been derived from the erosion of quartz- O shore Somalia Could rich Precambrian hinterlands to the west.

The thrusts seem to have a common detachment surface which may be the organic rich shale of Cenomanian–Turonian age. This may act as both a decollement surface and a source of oil to the Reveal an Oily Surprise overlying structural closures.

Seismic line through Tertiary fold belt showing large high amplitude fold and thrust structures.

Campanian/Santonian R R R

S S Turonian/Cenomanian

Albian – Aptian – Barremian S

Seismic attribute display of the same line: (Far – Near) * Far. The black colours indicate an increase in amplitude with o set (AVO) response.

42 GEOExPro October 2020 GEOExPro October 2020 44 A Reputable Publication | Quality Stories | Distributed Globally | Accessed Worldwide was a long narrow basin orientated Somalia undrilled reef play TGS One of the Last True north–south; a shape not conducive to oceanic circulatory patterns RICHARD HEDLEY, that result in upwelling currents. Hydrocarbon Frontiers TGS A second reason could be related Retain brand awareness to the presence of the Davie Ridge O shore Somalia has all the ingredients for nding big volumes of oil and gas, with reservoirs, Transform.  is long linear feature is source rocks and seals and multiple play-types including large fold-belt structures and an underwater high that parallels the during these challenging times! enormous reef closures. continental slope o shore Tanzania and Kenya which will have strongly in uenced oceanic currents in these In recent years the Government of Somalia has Southern and Central Somalia areas. Most of the wells o shore made signi cant and sustained progress towards  e seismic data reveals several large fold and thrust Kenya and Tanzania are drilled on Succeed in your business & marketing goals with lasting stability within the country. Legitimate public belts including a predominantly Tertiary fold belt, the shelf and slope west of the Davie institutions such as the Somali Petroleum Authority similar to o shore Mozambique in the Rovuma Basin. Ridge and therefore have not sampled (SPA) have been established and legislation has been  ere is also an older Cretaceous fold belt involving the basinal facies to the east of the GEO ExPro Magazine - in print and online. passed by both the president and the representatives in Cenomanian to Maastrichtian shelf and slope sediments ridge.  e jury is still out waiting for the bicameral Somali parliament to pave the way for the that have been thrust up and folded into a plethora of concrete proof of a ubiquitous CT oil announcement of the country’s First Licensing Round, large anticline structures. source rock in East Africa – but our which has a closing date in March 2021.  e interesting thing about this fold belt is that all the model provides some hope. Malampaya Field Ibrahim Ali Hussein, Chairman and CEO of SPA, thrust planes sole-out on a common detachment surface We can glean a lot of information and his newly formed team at the Petroleum Agency that we interpret to be Cenomanian–Turonian (CT) shales. about source rocks by looking on have been busy nalising the bid round protocols as It is well known that shales rich in organic carbon, and the opposite side of Africa. During well as contractual and scal terms and these will be particularly those in the oil window, can act as regional Cenomanian–Turonian times, the published on their website in the coming weeks detachment surfaces.  e model predicts that the shales Central Atlantic was a wide basin (http://somalialicensinground.com/). that act as slip surfaces for the thrusts can also be the with well-developed upwelling Two regional seismic surveys have been acquired source rock that supplies the oil to the overlying structures. zones.  ick layers of organic rich o shore.  e rst was shot in 2014 by SOMA Gas &  e Cenomanian–Turonian was a period of intense shale were deposited in both the Oil, a private oil company founded chie y to explore global anoxia with euxinic conditions developed shelf/slope setting and also in the for natural resources in Somalia and the second by throughout the ocean  oor deep water as well as along deepwater setting.  e thick oil Spectrum (now part of TGS) in 2016. Both surveys are the upper continental slopes and outer shelves.  e shales of Tarfaya in Morocco and modern, high quality, long o set seismic. resulting CT sediments are rich in organic matter owing the La Luna Formation in Venezuela to a combination of two factors: high phytoplankton are examples of thick, high quality productivity source rocks deposited in a shelf/ Comparison of an undrilled Jurassic carbonate build-up in Somalia (top) with a similar looking (Tertiary) Location map showing bid round blocks (light blue) and available 2D seismic data (orange lines). carbonate build-up in the Philippines (bottom). The Malampaya  eld, operated by Shell, has reserves of 3 caused by slope setting.  e recent Guyana Tcfg and 85 MMbc. Giant reef closures are mapped o Somalia – some with up to 1,000 km2 closure. increased and Suriname oil discoveries testify TGS nutrient supply to high quality oil-prone source rocks also deposited in the Within the Somalia Arch we can clearly see the Permo- in upwelling deepwater basinal setting. We expect similar conditions were Triassic–Early Jurassic (Karoo) syn-rift fault blocks zones and greater present in the deepwater Somali Basin during CT times. truncated by the break-up unconformity. Above the preservation at  e probability of nding good quality reservoirs is high. unconformity, and at good drillable depths, are monstrously the seabed under  ick, quartz-rich sandstones of Cretaceous and Tertiary big Jurassic reefs with enormous four-way closures (see anoxic conditions. age with high porosity are expected in the southern and image above). One mapped closure is more than 1,000 km2. Geoscientists central Somalia basins as a result of erosion from largely On the conjugate margin in Madagascar, the Karoo has high reading this article Precambrian granitic basement plus reworking of older quality proven source rocks in the Early Triassic (lacustrine will rightly ask Karoo sandstones.  e burial depths are not high, so we Type I) and Early Jurassic (marine Type II).  e Early Triassic why thick, high expect good porosity to be maintained. lacustrine source rock has sourced more than 22 Bbo in the TOC source rocks All things considered, the fold belts have all the Bemolanga/Tisimoro oil elds of Madagascar. Similar aged of CT age have not ingredients for success in nding large volumes of oil and gas source rocks may be present in northern o shore Somalia. been encountered in commercial quantities. Another possible source rock would be coeval Late in wells drilled Jurassic shales on the basinward side of the reefs.  ese in nearby Kenya Northern Somalia onlap and eventually drown the reefs – perhaps acting as GEO ExPro 2021 Media Guide and Tanzania.  e northern part of o shore Somalia has a very di erent both intraformational source and seal.  ere could be geology to that found to the south.  e reason for this is related several reasons to the creation of a huge uplifted structural arch, known as Exciting New Basin for this, including the Somalia Arch, at the start of the Late Cretaceous. Strong Overall, the o shore Somalia Basin promises to be an exciting OUT NOW the fact that transpressional forces in the crust were created as a result of new basin to explore in the years ahead. Hopefully, there will be during CT times India separating from Madagascar and this produced long success there, and as a result future oil revenues will help Somalia the Somali Basin wavelength buckle folds across a wide area of East Africa. continue its path of reform, bringing prosperity to its people.

GEOExPro October 2020 45 46 GEOExPro October 2020 www.geoexpro.com/advertise GEOExPro October 2020 47 Energy Transition Geoscience in a Low Carbon Future

The role of a petroleum geoscientist is evolving with the energy transition, DEAN BAKER, but it is still of vital importance to the future of energy. RISC Advisory

Recent events regarding the global Covid-19 pandemic have The Future of the O&G Industry somewhat dominated media focus in the last six months or so, Th ere are a multitude of forecasts available in the public but for the 12–18 months prior to this the publicity and media domain for future global energy demand and energy sources coverage of the global ‘climate emergency’ and the energy (see fi gure on facing page for BP’s 2020 forecast). Many transition were very much a key focus area. As a geoscientist diff erent scenarios are forecast by diff erent organisations in the oil and gas industry, I have found myself questioning with regards to the pace of technology development, my role and that of my industry in our contribution to the population growth, electrifi cation of transportation, climate emergency, but more importantly, in the possible increased use of renewables etc. Irrespective of the scenario solution. Th ree main questions come to my mind: does the modelled, most outcomes predict that oil and gas will oil and gas industry have a future and how does this fi t into still make up a very signifi cant proportion of the global the energy transition; how is the petroleum geoscientist’s role energy mix in 2040 and beyond: typically 40–60%, with likely to change; and in what other ways could a geoscientist coal, renewables, hydroelectric and nuclear making up the contribute to the energy transition? remainder. In this article, I will avoid discussion on the science Th is suggests oil and gas as energy sources are here to stay of climate change, government policy, politics, or related for some time yet, in particular gas which is seen as the key social issues – there are people far better qualifi ed than me ‘transition fuel’. It is plentiful in supply, reasonably cheap to to comment on these topics. Instead, this article will focus produce and relatively clean in comparison to coal or oil. It specifi cally on the future role of a geoscientist in the energy is widely accepted that gas use for energy production is key transition world, sharing my opinion and the insights I have to bridge the gap between reduction in fossil fuels and the gained from recent publicity and the many discussions I have increase in more sustainable renewable energy sources. In had after working within the industry for the last 14 years. this regard, and perhaps counterintuitively, it is important © Coatsey/Dreamstime.com ©

48 GEOExPro October 2020 to consider the oil and gas industry is part of the solution in moving towards a low carbon renewable energy future. Quite simply, without the affordable and reliable energy that oil and gas provide it would not be possible to transition to renewable energy sources. What does this mean for the petroleum geoscientist? Well, more than likely these skills are still going to be required for some time to come to explore for and produce the hydrocarbons needed to fulfil global energy demand. However, employment within the industry will likely shift away from the majors towards national oil companies, non-OECD (Organisation for Economic Co-operation and Development) countries and smaller players as the majors transition away from traditional oil and gas exploration to becoming energy companies. For those companies still pursuing oil and gas, in my opinion we are likely to see a much more rigorous project selection criteria adopted by companies in line with an increased focus on environmental, social and governance policies, also heavily linked to the sources of financing BP Energy Outlook 2020 available. There will be a focus on projects that have the BP Energy Outlook 2020 forecasts for primary energy consumption by source. potential for lower environmental and climatic impact, reducing the pool of potential oil and gas development require the skills, experience, and knowledge of geoscientists. projects. Furthermore, whilst majors and larger companies might employ more modern technologies and analysis methods, the Digitalisation Cannot Do Everything workflows and technologies we are familiar with today will Digitalisation across the oil and gas industry is something continue to be used extensively so these skills will still be that has received a lot of attention since the oil price crash required. Nevertheless, it will be important for geoscientists in 2014/15 as companies sought to be more efficient and to evolve their skill set to adapt to more digitalisation, save costs. This broad term, digitalisation, can be used supported by training across the industry and at university to describe a variety of technological advancements and programme level. new ways of working, including artificial intelligence, big data, analytics, internet of things and electronic remote Critical Skills Still Required monitoring – to name but a few. Many research projects, In addition to the need for continuing oil and gas exploration particularly by the majors, are advancing the technologies to and production to fill future energy needs, the demand for the point of implementation in everyday operations. In the geoscientists is likely to increase over the next decade and next decade or so I believe we are likely to see large changes beyond in a number of other areas: in the way the industry works, particularly in terms of data processing and analysis and the monitoring of operations Carbon Capture and Storage (CCS): This is a topic and production systems. One of the key facilitators to this is receiving a significant amount of attention in the oil and the continued uptake and advancement in ‘cloud computing’, gas industry and by governments as a potential solution to with large increases in computing power and affordability reducing CO₂ emissions. The notion of injecting CO₂ into now available. depleted hydrocarbon reservoirs has been around for well For the geoscientist the increases in computing power over a decade now, but has never really made any major available via the cloud are likely to greatly affect the steps forward; it has always been challenged in terms of subsurface workflow giving them the ability to analyse economic viability, not to mention many other technical larger quantities of data more quickly. This can optimise and aspects. Unless there are some major changes in government automate significant parts of the subsurface workflow which policy, as well as incentives and increases in funding for can in turn free the geoscientist to apply critical thinking research, we could still be decades away from viable CCS and skills to subsurface challenges. One example might be projects being sanctioned and thus providing a notable automated seismic screening and interpretation, with key contribution to reduction in greenhouse gases. However, inputs from the geoscientist provided at the beginning to set some governments and major oil companies are conducting up a project and quality control at the end to review, with active research projects and in the last 18 months or so automation undertaking of the bulk of the process. there is a general feeling of slowly gathering momentum and In this example, as in many others, despite significant interest in the subject. This progress is certainly welcomed, automation the role of the geoscientist is still an important but we need to do a lot more. Indeed, some commentators one to provide technical inputs, quality control and review of argue that if we continue to use fossil fuels in the quantities results. The critical thinking and decision-making will still forecast over the next two to three decades and still want

GEOExPro October 2020 49 Energy Transition

a) b) BP Energy Outlook 2020

Global carbon emissions from energy use (a) and Carbon emissions by sector (b). Ranges show 10th and 90th percentiles of IPCC scenarios.

to achieve Paris climate change targets then CCS will be their flow behaviour, in addition to modelling and monitoring essential and might need to capture more than 55% of reservoirs once injection and storage commences. produced CO₂. The role of geoscientists in this future industry will be Geothermal Energy: A clean and renewable energy critical to identify carbon capture storage sites by analysing source, geothermal is likely to increase in popularity in the hydrocarbon reservoirs and developing an understanding of future, particularly in those regions where the underlying geology is supportive. The role of a geoscientist is varied

Belgium’s first offshore wind farm, Thornton Bank, under construction in the North Sea. Geoscience skills learnt in the oil industry are needed when selecting wind farm sites. Jan Oelker/WikipediaJan

50 GEOExPro October 2020 Freenzphotos.com

Wairakei Power Station is a geothermal power station near the Wairakei Geothermal Field in New Zealand. within this industry and geoscientists have a role to play during exploration, development, and production phases of geothermal projects. A geothermal geologist probably has more in common with mineral exploration than , but there are still a lot of similarities to the work of a petroleum geoscientist including mapping geology and geological features, sample analysis, examining cores and cuttings, building subsurface models and siting and planning wells.

Mineral Exploration: Mining and mineral exploration has always been a popular career choice for many geologists following graduation and provides an exciting and rewarding profession for those involved. A career in mineral exploration could offer a good avenue for petroleum geoscientists in the energy transition as we move away from fossil fuels and traditional petroleum geology roles. Continued electrification of transport and energy storage will be supported with improvements in battery technology which are predicted to increase exponentially over the next couple of decades. This will vastly increase the need for key minerals such as lithium and exploration and mining for these minerals will be a major industry employer for geoscientists.

Part of the Solution My research and interactions with other industry professionals had led me to the conclusion that the role of a geoscientist is an important one in the future energy transition, whether that be in continuing to support the in exploration for oil and gas to meet global energy demand; a switch in focus to gas as ‘the key transition fuel’; or supporting new growth industries such as CCS mineral exploration; or contributing towards renewable energy industries such as geothermal and wind. There are likely to be significant changes ahead and adaptions required for our industry, but if we embrace these and face them head-on with a focus on effective communication with governments and the general public then our industry can hopefully be viewed, quite rightly, as part of the solution for energy transition rather than the problem itself.

GEOExPro October 2020 51 Energy Transition Ruminations on CO₂

SUSAN FELLOWS, Carbon dioxide: least wanted – or most wanted accessory? Computer Modelling Group Ltd

Carbon dioxide (CO₂) is not a popular From the E&P side, that same fl ooding. As heavy industry seeks to gas these days. Industry, governments injection well is a conduit into the capture CO₂, the E&P industry now and even individuals are actively trying unknown, with highly corrosive CO₂ perceives a reliable future supply of CO₂ to reduce its production, and dispose of damaging piping and casing integrity; for EOR practice where the reservoir what is produced, in such a way that it and the same highly reactive CO₂ formation and fl uid characteristics are disappears forever. Over the last decade entering the saline aquifer or depleted suitable. Are CO₂ storage and CO₂EOR or more, the capture and disposal of gas reservoir and interacting with the competing concepts, or a mutually CO₂ has created a whole new industry existing fl uid and rock chemistry. In benefi cial arrangement? dedicated to fi nding ways of capturing contrast, if the reactive potential of and storing the unwanted gas and CO₂ is to be utilised in EOR, it should Basics of CO₂ Storage preventing it entering our atmosphere. be remarked that the injected CO₂ is CO₂ is trapped underground and Meanwhile, E&P companies are re- used to sweep the reservoir, and thus contained therein by diff erent orientating themselves to become goes down the injection well, only mechanisms, each acting over a waste-disposal services, by off ering to subsequently come back up the diff erent timescale. existing infrastructure and ‘empty’ production well, where it needs to be is utilised to model, evaluate and storage facilities. recaptured. manage the CO₂ injection strategy, and Both in the North Sea arena and Th e objectives of CO₂ storage predict the movement of the gas in the globally, much technical, logistical and and CO₂EOR are very diff erent. Th e subsurface where it becomes trapped planning eff ort is focused on the use motivation for CO₂ storage is to reduce and stored. Th e mechanisms include: of carbon capture and storage (CCS) greenhouse gases utilising depleted Structural Trapping: Th e O₂ C is methods to dispose of unwanted CO₂, oil and gas reservoirs and also saline trapped as a mobile gas (super critical both in depleted gas fi elds such as those aquifers. CO₂ is highly soluble in the fl uid) in the geological structure, of the Southern North Sea Basin, or aqueous phase and saline aquifers by an impermeable cap rock. What in saline aquifers such as exist in the have a large capacity to store it (Figure had applied as a physical trapping Central North Sea Basin. Th ere are also 1). Th e motivation for CO₂EOR, by mechanism for the hydrocarbons in a enthusiastic advocates for the use of the contrast, is to increase the recovery depleted reservoir also applies to CO₂. proposed unwanted volumes of CO₂ to factor of an oil reservoir subsequent to Continued injection of CO₂increases be used in CO₂ enhanced oil recovery primary depletion and secondary water the subsurface pressure, and careful (EOR) from mature fi elds. Th e US has employed CO₂EOR for over a decade Figure 1: Physics of CO₂storage. with good results, and there are those who seek to replicate this in the North Sea.

Who Uses What and Where? CCS and CO₂EOR are both good ideas, but good ideas do not always come with all the practicalities nicely packaged. Th e reality of the North Sea presents specifi c constraints and considerations, linked to water depths, well location and well spacing; and in the northern North Sea area particularly, extreme weather conditions exist. Beyond E&P, much of industry sees the injection of CO₂ into ‘vast caverns beneath the sea’, as a ‘cure-all’ to their CO₂ problems. Th e perception of CO₂ disposal is too often an injection well into an infi nite hole below ground, and preferably, beneath the sea…. CMG

52 GEOExPro October 2020 CMG

Figure 2: Evolution of gas saturation in the aquifer and in overlaying formations due to leakage through caprocks. (SPE 125848 Nghiem et al 2009) monitoring is required to ensure that the cap rock does not The Basics of CO₂EOR fracture, resulting in the CO₂ leaking upwards and away CO₂ may be injected into a reservoir as a form of EOR process,

(Figure 2). typically either CO₂WAG (CO₂ plus high salinity water)

Residual Gas Trapping: Depending upon CO₂ movement, (Figure 4), or CO₂LSWAG (CO₂ plus low salinity water). Note

(drainage or imbibition), and hysteresis effects, CO₂ can be that in the US onshore unconventional plays, CO₂EOR takes trapped as an immobile gas in the pore space. This method is the form of ‘huff and puff’, a process not applicable in the most effective in low-permeability aquifers and is accelerated North Sea. Injected CO₂ develops miscibility through multiple by water injection. Figure 3: Security of CO2 storage versus time. Solubility Trapping: CO₂ is highly soluble in brine and becomes a soluble component in the aquifer brine. Aquifers ‘flow’ underground, albeit on extended timescales, so there is the potential for migration of the CO₂ -rich water out of the designated injection or storage area.

Mineralisation: As the dissolved CO₂ content of the aquifer brine increases, so does the acidity of the Metz et al., ICCP Report 2005 brine. This leads to dissolution of some rock minerals, and deposition of carbonate minerals such as calcite, dolomite and siderite. In other words, the injected CO₂ is bound into a solid physical state. This is the safest storage mechanism, but there are many uncertainties in predicting when and where dissolution and precipitation may take place in the subsurface. Residual Gas Trapping and Solubility Trapping are the most important CO₂ trapping mechanisms (Figure 3). High-permeability aquifers favour Solubility Trapping while low-permeability ones favour Residual Gas Trapping. Reservoir engineering techniques can be used to accelerate and increase the amount of Residual Gas Trapping. Reservoir simulation coupled with geomechanical simulation must be undertaken to determine and manage structural integrity, as demonstrated in Figure 2.

GEOExPro October 2020 53 Energy Transition Global CCS Institute CCS Global

Figure 4: Enhanced oil recovery using CO2. contacts with the reservoir oil. A certain pressure is needed to designing a CO₂EOR project, these parameters are also the achieve miscibility, which is called the minimum miscibility focus, but for different reasons. Injection during CO₂ storage pressure (MMP). is most likely to be continuous, (supply dependent), and will Above its critical conditions (7,390 kPa, 31°C), the density continue for years or decades, with the aim of injecting in such of CO₂ is in the range of the reservoir oil density, but its a way as to maximise trapping of the CO₂ in the reservoir. Thus viscosity is less, which results in an unfavourable mobility injector location, and injection rate and pressure, are designed ratio. Injecting CO₂ swells the oil and the saturation pressure to optimise residual gas trapping and solubilisation of the CO₂ changes. Increasing the CO₂ injection pressure above the in the reservoir brine. Conversely, in a CO₂EOR project, the

MMP increases the CO₂ density, resulting in better sweep CO₂ will not be injected continually, but in a series of pulses, efficiency and a higher oil recovery. with the aim to recover as much of the injected gas as possible, When designing a CO₂EOR project, there are multiple both for re-injection, (supply dependent), and because the less considerations, including the reservoir formation; the PVT of CO₂ that is trapped in the reservoir, the more effective is the the hydrocarbon fluid; the reservoir heterogeneity and thus hydrocarbon recovery process. overall permeability distribution. Of particular importance is Storage of CO₂ and use of it as an EOR agent are different the vertical permeability and associated potential for CO₂–oil subsurface processes. This does not mean that they cannot be segregation. Offshore, inter-well distance is crucial, with the managed together, either as sequential field operations, or as potential to fall below the miscibility pressure and lose the separate operations in different reservoir compartments. It is flood efficacy. Other factors such as water blocking, viscous for those working on the projects to access accordingly. The fingering, hysteresis and asphaltene precipitation must also discussion here is necessarily simplistic, with the intention be considered. Reservoir simulation is an essential part of of raising some of the practicalities of injecting CO₂ into the the design phase and subsequent evaluation of the success subsurface, whether to dispose of it in the long term, or to of the miscible flood process; type of flood, flow mechanism, gain additional value in enhanced hydrocarbon recovery in (vertical flood or gravity segregation), WAG or LSWAG and the short term. slug size. Asphaltene deposition can lead to permeability reduction and plugging especially around the well area, and References as with infrastructure corrosion, is an undesirable effect of Metz, B., Davidson, O., de Coninck, H., Loos, M., and injecting CO₂. Meyer, L. (eds), IPCC (2005). Carbon Dioxide Capture and Storage. Cambridge University Press. Competing – or Mutually Beneficial? Nghiem L., Shrivastava V., Tran D., Kohse B., Hassam M. and

When designing a CO₂ storage project, optimisation focuses Yang C. (2009). Simulation of CO2 Storage in Saline Aquifers. on the location of the injector wells, the injector rate, injection 2009 SPE/EAGE Reservoir Characterization and Simulation pressure and the duration of the injection period. When Conference.

54 GEOExPro October 2020 GEOExPro October 2020 55 Exploration Tantalising Opportunities in Angola Angola’s Onshore Kwanza Basin off ers an underexplored basin with a world class petroleum system.

MATT TYRRELL and ALESSANDRO COLLA, Trois Geoconsulting BV; MIKE OEHLERS, Tectosat Ltd

Seasoned explorers of Africa and Th ere are, however, onshore basins A key milestone occurred in 1955 the Atlantic margins will be familiar where this quandary is not so apparent; when the post-salt Benfi ca oil fi eld was with the quandary of choosing where extensive high quality datasets discovered just south of Luanda, after between off shore and onshore acreage. are available and early exploration which exploration drilling peaked; Off shore acreage typically off ers large, has suitably de-risked proven pre- and by the late 1970s 133 wells had been inexpensive seismic datasets with post-salt petroleum plays. One such drilled. Th is era of activity saw the which to identify prospects, but the example is the Onshore Kwanza Basin discovery of 11 oil fi elds, as well as a few costs of drilling and developing these of Angola – a Mesozoic salt basin with gas fi elds, with the largest containing require signifi cant inward investment. numerous undeveloped fi elds, a library more than 200 MMboe, made possible Conversely, onshore acreage allows rich in accessible yet low-cost exploration by the availability of 11,500 line-km numerous wells to be drilled at a low datasets and local refi neries and markets of dynamite 2D seismic data. Th e last cost, but the ability to locate and de-risk for hydrocarbons once they are produced. onshore fi eld discovery was in 1972 and prospects is limited by the expense Furthermore, a licence round that the last well was drilled in 1982, from and paucity of exploration datasets, opens towards the end of 2020, supported when on interest in the onshore declined, particularly seismic. by new oil and gas laws and fi scal in part due to socio-political stability Th is quandary is particularly incentives, provides the opportunity for risks but more likely due to the early apparent in the coastal basins of West oil companies to secure rights to this successes of off shore exploration. Only Africa, where the Mesozoic sedimentary acreage, appraise discovered fi elds and nine oil fi elds have ever been reported as successions, including salt, extend into potentially fast-track commercially viable having been put onto production, which the onshore domain. In this basin, hydrocarbon production. include the Cacuaco and Puaca fi elds, seasoned explorers will be tantalised both with pre-salt reservoirs. by the opportunity to drill salt-induced Underexplored Pre-Salt Although at fi rst it appears that the prospects within a proven petroleum To understand the future potential of Onshore Kwanza has been considerably system and will be seeking the necessary the Onshore Kwanza Basin, we must drilled, analysis of well penetrations datasets with which to de-risk them. fi rst understand its exploration history. and results tells a story of high success

The Miradouro da Lua near Luanda. The geology shows the building and uplift of the Late Neogene Paleo-Cuanza delta. David Mark/PixabayDavid 56 GEOExPro October 2020 rates in post-salt wildcats contrasted with a prospective yet significantly underexplored pre-salt succession. Of the 237 wells drilled, just 28 penetrated beneath the salt; four pre-salt fields were discovered prior to 1971 (Cacuaco, Uacongo, Puaca and Morro Liso) despite only three wells testing a meaningful section of pre-salt stratigraphy. When our seasoned explorers analyse the results of these pre-salt wells they must be left pondering what might have been found had the operator drilled a little deeper. An initial observation is that the majority of pre-salt penetrations were drilled from wellheads located for post-salt prospects with only a handful of wells spudded with a pre-salt objective. Furthermore, assumptions about 1960s and 1970s technology and know-how suggest that modern field appraisal methodologies could reveal where discovered fields may actually be commercial, whilst advanced well stimulation techniques could lower the commercial threshold.

Updated Datasets Support Exploration In 2010 and 2011, 2,581 line-km of high quality 2D seismic data was acquired followed by the acquisition of high resolution aeromagnetic data. A new GIS GeoDatabase named KMAP-2020, commissioned by Sonangol in 2015, was then completed as part of the reassessment of the remaining oil potential ahead of licence rounds. This product, available for the whole onshore basin or for individual blocks, includes outcrop information, petrographic studies and palaeontological reports from recent field trips together with seismic profiles, well stratigraphy panels and geosections. The KMAP-2020 database has recently been further refined by the inclusion of modern satellite imagery supplied by specialist, Tectosat Ltd. Using Landsat imagery, SRTM DEM, ASTER and PALSAR Radar data*, the whole basin has been remapped at a much more comprehensive 1:50,000 scale involving interpretation at 1:25,000 scale, with additional integration of lithological detail from some 3,000 field sample points.

The resulting updates to the surface geology Trois maps within the KMAP-2020 database have positive Revised KMAP-2020 geological map derived from recent satellite imagery and implications for de-risking the underlying petroleum field studies. Pre-salt well penetrations and 2020 License Round blocks are shown. systems. Halokinetic activity is evinced in anomalous domes and basins showing salt withdrawal and folding the pre-salt Cacuaco Field north-east of Luanda suggest that adjacent to the main bounding faults of the Tertiary troughs. the sub-salt section should be suitably charged. Fault expressions mapped at surface have been used to understand structural controls related to various tectonic Underexplored Area in New Licence Round episodes. Where it is shown that many of the Tertiary-aged An integration of past exploration results, available seismic faults are soft-linked to deeper syn-rift structures, the charge and well datasets with the KMAP-2020 database (which of post-salt reservoirs with pre-salt oil can be de-risked. includes the satellite imagery interpretation) demonstrate that Similarly, areas of Tertiary uplift are observed in the vicinity the Onshore Kwanza Basin is a world class petroleum basin of Blocks 11 and 12 where present-day river systems are seen that in recent decades has been considerably underexplored. to have incised; this uplift may have hinged to the north at The post-salt section has numerous anticlinal closures that the Cabo Ledo fault. These details are key in determining are untested; where these have been drilled the structures exhibit long-distance migration paths from known source kitchens, good reservoir qualities and host viable oil fields, such as those including the offshore, into pre-salt and post-salt structures; at Quenguela and Benfica. Where sampled, the pre-salt is shown indeed, the presence of basin margin oil seeps together with to exhibit good quality carbonate reservoirs formed by coquina

GEOExPro October 2020 57 Exploration shoals with vuggy porosities as well as fluvial-deltaic sandstones. The hydrocarbons encountered here are light oils with gas and with no known encounters of CO2 or high sulphur content. When the results of the updated ArcGIS geological study are combined with available seismic and well datasets, conclusions can be drawn that suggest that the upcoming licence round may be the trigger for the first commercial production of oil from onshore Kwanza. Recent announcements

by the newly formed Sonangol. ANPG (National Agency of Simplified example well-section from the KMAP-2020 report; note the limited pre-salt penetration in the Bom Jesus well. Petroleum, Gas and Biofuels) have defined a strategy for the allocation of petroleum concessions including open acreage Exceptional Opportunity within all of Angola’s basins. Concessions will be awarded The history books of exploration bear witness to a multitude through a process of public tender, restricted public tender and of junior exploration companies that secured onshore acreage, direct negotiation over a period of seven years, starting in 2019 within a known petroleum province, yet were unable to and culminating in 2025. The blocks offered by public tender successfully demonstrate to investors and potential farm-in are those that are deemed exploration blocks that have not partners that they could cost effectively de-risk a drilling location. formerly been abandoned and restored to the state. The Onshore Kwanza Basin is different in that it offers The blocks of the Onshore Kwanza Basin have been the opportunity to secure acreage containing a post-salt field announced as a part of the 2020 licensing round, which will or prospect that can potentially be appraised and brought open in the fourth quarter of 2020. Blocks KON5, KON6, into production, providing cash-flow to fund further pre-salt KON8, KON9, KON17 and KON20 are offered by public tender exploration where the prize may be bigger. The 2020 Angola and these blocks all offer excellent potential for exploration as Licence Round should therefore be in the plans of all junior well as opportunities to appraise and develop discovered fields. and mid-sized oil companies. In August this year, the ANPG held a Clarification Session as a precursor to the opening of the round; during this session * SRTM DEM (Shuttle Radar Topography Mission – Digital senior members of ANPG gave informative presentations and Elevation Mapping), ASTER (Advanced Spaceborne Thermal clarified the timeline for the submissions of bids and signature Emission and Reflection Radiometer), PALSAR (Phased Array of the contracts. type L-band Synthetic Aperture Radar)

KMAP-2020 PALSAR data with shaded DEM showing the geological structure around the Cabo Ledo fault; note the differentiation between deep- seated and shallow Tectosat Ltd faulting.

58 GEOExPro October 2020 GEOExPro October 2020 59 Industry Issues Tackling the Local Content Gap E&P companies working in Africa have long faced political pressure to maximise local content, but in today’s Covid world it makes more business sense than ever to localise supply chains, increase the competitiveness of home-grown WILLIAM POLLEN, businesses and thus contribute to sustainable economic development. Invest in Africa

Corporations working in Africa, including Ambitious Vision Oil, which was a founding partner, those in the oil and gas sector, are under Invest in Africa (IIA) is a not-for-profi t as well as other oil industry players regulatory and reputational pressure to organisation with a simple yet ambitious such as Woodside, BP, Cairn, Kosmos, create local jobs and opportunities. Th e vision: to create thriving African and Shell, and also local more astute of them also look for ways economies. It does this by helping and international law fi rms and banks to ensure this approach where possible and management consultants like complements the host EY, whilst donor funders include the government’s long- African Development Bank, DFID and term national Mastercard Foundation. IIA believes development that by continuously creating strategic plans. partnerships with corporate associates, Th is local enterprise, government bodies and donor agencies it will be able to create more value, identify new clients and markets and thus create prospering African economies. Coordination of objectives, time ‘nationalised’ or ‘local content’ approach also makes business sense; the more of your supply chain that is localised, the less exposed your operations are to customs delays, import taxes, exchange rate fl uctuations – and Covid-19 has only Shutterstock emphasised the further risks of relying on international supply chains. Meanwhile, African small to medium-size enterprises (SME) often lack skills and the business understanding required to allow them to compete in a new or international market. Th ey need access to fi nance frames and priorities is often lacking that will enable them to scale up their between industry players and the businesses, whilst reliable, fair and public sector, which is why IIA’s model, transparent opportunities and market which bridges the private and public information can be hard to fi nd. Industry sector, is so important to its success. level skills and standards pose another African SMEs to grow through enabling An informed and consistent dialogue signifi cant barrier to local businesses, them to gain better access to skills, between these parties is also critical especially if foreign investors’ ethics, markets and fi nance. to building trust, avoiding tensions compliance and environment, health and IIA is a collaboration that unites the and delays that too often spiral out safety standards are imposed, top down, private sector, donors and governments of control, to everyone’s detriment, without any explanation or support to in order to pool needs and resources especially the local businesses and local businesses to understand and attain and thus create more timely, impactful economy who as a result are made to these ways of working. and cost-effi cient solutions than would wait for the project go ahead. How can this shared challenge be be achieved if they each acted alone. Th e impact that IIA makes is tackled? Private sector partners include Tullow measured by the number of jobs created,

60 GEOExPro October 2020 IIA any improvement in competitiveness The African Partner Pool was operational risks they might face, or seen and the creation of new linkages to launched in Ghana in 2014 and Kenya analyse the key issues in logistics and contracts and finance. Having started in 2016, with plans to extend it to other supply chains; in African businesses, the in 2014 initially focused on Ghana and markets in the near future. One company challenge is not big data, as in developed Kenya, by 2019 IIA had activities in that has benefitted from joining it is Edge countries, but simply finding the data Senegal, Mauritania and Zambia and S&S, a Ghanaian sourcing and supply itself. had helped connect SMEs in those company, which was frustrated by little countries to contracts worth over $165m exposure to multinational companies Access to Skills and Finance and access over $5m worth of finance operating in the country, with business Members of the African Partner from banks to grow their businesses. limited to the ‘same old clients’. The Pool also have access to training To date it has created approximately only way they could hear of tenders and coaching through IIA’s Business 65,000 jobs, all delivered by local teams. from multinational companies was by Linkage Programme, which offers IIA has an ambitious target of enabling scanning through newspapers to find if coaching and mentorship interventions the creation of 250,000 jobs and $1bn of any had been advertised. Within a few that assist SMEs to scale up and fast contracts won by SMEs by 2027. weeks of signing onto the Portal, where track their businesses in order to they could see many tenders from lots become globally competitive – giving Finding Opportunities of businesses all in one place, they had them not just technical but also ‘life These are ambitious plans – but how is responded to a tender request from skills’. The African Development Bank this done in practice? UT Bank and eventually won a supply and the Dutch Development Bank In order to improve access to contract from them. They have also been have provided funding of $4m for this markets, IIA has developed an online able to engage with a number of other programme, which is delivered by marketplace it calls the African Partner companies, including . IIA and its partners. Recently IIA has Pool, which allows SMEs to promote the For the international company rolled out a Covid Survival Toolkit products and services they can deliver looking for local skills, the African in partnership with Mastercard and the standards they can deliver to. Partner Pool provides access to Foundation, available on IIA’s website They can also access information on businesses that have already been for free to African SMEs. This toolkit industry fundamentals, project briefings independently validated from across features a series of live webinars with and other materials to help them start a range of sectors. The system allows industry experts providing solutions to their journey into a new sector. them to search and filter by service and the biggest problems Covid has created Organisations coming into Africa a number of other key criteria, which for SMEs. need to find local suppliers who will reduces the time and effort as well as be able to work effectively with them, cost required To date IIA estimates that $165m worth of deals have been done through but local firms often find it difficult in finding the the African Partner Pool. to access these opportunities, and the right supplier, African Partner Pool makes it easier especially for a IIA for big companies to find the right local new entrant to an suppliers to work with. Local businesses African country. that register on it get the chance to IIA also supplies a display their products and services to series of ‘Investor both international and domestic buyers Guides’, available and they can also view live tender through its opportunities and register their interest website, that can in them. In order to give the local help an incoming suppliers the best chance to succeed, the company portal includes practical guides on how understand to work with big companies and what it the economic, takes to gain a competitive advantage. financial and

GEOExPro October 2020 61 Industry Issues

The aim of IIA’s model is to deliver IIA training at a much reduced price in order to help African companies to develop to the stage at which they can win new clients, not just locally but also regionally and internationally, enable efficiencies to increase their profits, and gain access to finance and thus create new jobs. In order to benefit from this programme, companies must be at least two years old and have between 15 and 100 employees. A transparent procurement system is also important to ensure growth in African business, so companies applying to the Business Linkage Programme must be able to demonstrate efforts to be transparent and to embed governance standards. Managers in one company that took advantage of this capacity building Invest in Africa has partnered with various organisations to connect woman-owned businesses to opportunities. programme reported that they quickly saw clear positive results. Applying US$5m of credit has been disbursed to Thus it can be seen that IIA has what they learnt, they changed the way SMEs through IIA’s banking partners. developed a coordinated industry-led they worked, found that scrutinising solution, with public sector support expenses more effectively ensured they Tracking Progress and organised funding, which links got better value for money, and as a To monitor the impact of these multinationals and larger businesses with result salaries have risen by 50%, staff programmes IIA have developed a local verified SMEs, that is demand-led numbers have increased from twelve socio-economic impact model to assess and supports national development, to eighteen, and they even acquired and understand how its work benefits improves the investment climate and property which is being developed to local economies, looking at three major saves both parties time and money. The serve as their new office and showroom. aspects: value retained in the local international companies have a cost- Previously IIA ran a business economy, the number of jobs supported effective and efficient way of fulfilling accelerator programme that gave SMEs and the increase in contracts won. For their local content requirements that will access to senior consultants from EY at every deal that goes through the African leave a sustainable, impactful and scalable a heavily subsidised rate to help them Partner Pool, the organisation captures legacy, while the SMEs gain access to design and implement the key systems the value and the sector involved in the skills, contracts and finance to build long- and structures that are necessary for tender and uses the socio-economic term capacity for both themselves and greater efficiency and sustainable growth. model to track the value retained in their countries. A win-win situation! IIA also provides an Access to the country through taxes, profits and And with the African Free Trade Finance Programme for African Partner household income. It can also track Agreement (AfCFTA) – converting Pool members which helps registered jobs created in various sectors and Africa’s 54 markets into one common, SMEs to develop structures and ultimately calculate the overall impact tariff-free trading block worth over protocols that will help them reduce risk on the economy through the purchasing $3 trillion – recently ratified, the in order to encourage banks to advance of goods and services locally rather than opportunity for quality home-grown them loans. So far, approximately from abroad. African businesses will only increase. IIA

62 GEOExPro October 2020 CGG has been investing in Gabon since 1932. Since those early days, the company has moved from the shallow waters, to the shelf and most recently to the thick sedimentary Gabon: Staying Ahead section of the lower slope and abyssal plain. In 2015, CGG acquired 25,168 km2 of 3D BroadSeis™ seismic and potential eld data, followed by a further 9,595 km of long-o set 2D seismic data in 2018. of the Herd in the To complement its acquisition of geophysical data, CGG has conducted three independent, regional, geological interpretation JumpStart™ projects. These highlight the prospectivity of the targeted geological domain and bene t from the newly acquired geophysical data.

Open Blocks Currently, the shallow water shelf plays of Gabon are considered mature. Explorationists AVO Models Ultra-Deep Waters Recent Discovery have recently followed these plays into deeper waters and enjoyed some success with the Other Wells drilling of the Boudji-1 and Ivela-1 wells. However, with declining production levels in Gabon Deep Water 2D (2,595 km) and falling drilling prices, explorationists are now looking to open up the inferred ultra- Gabon South Basin 3D BroadSeis (25,168 km2) 2D seismic dip line o shore Gabon. deepwater plays, which have the potential for giant accumulations of hydrocarbons. Insert on main foldout line: AVO gradient intercept plot. Twt SW BSR NE 5

6

Albian/Turonian 7 Unconformity Surface

Insert

8 SALT DOMAIN

9

10

64 GEOExPro October 2020 GEOExPro October 2020 66 A seismic- and well- based approach reduces De-Risking Deepwater uncertainty over source rocks to bring insight to Plays O shore Gabon the nal frontier.

JAKE BERRYMAN and GREGOR DUVAL, CGG

When CGG acquired its 3D deepwater Gabon structural and stratigraphic combination traps in the South dataset in 2015, an extremely thick section post-rift series of the nearby basins (i.e. Gabon North of discontinuous, bright-amplitude re ectors was Basin and Lower Congo Basin). A number of  elds found observed between the seabed and the Top Oligocene in those basins have proven post-rift source rocks, such unconformity.  is section originates from the Congo as the Turonian Azile Formation, the Cenomanian Cap Fan and pinches out against the palaeoslope, within the Lopez Formation and the Albian Madiela Formation. In CGG 3D survey area.  is sedimentary formation expands the Gabon South Basin only the syn-rift source rocks of (Left) AVO models for the Top Cenomanian and Top Turonian; (right) AVO cross plot for the Top Cenomanian and Top Turonian. towards the ultra-deepwater domain, where it thickens the Melania and Kissenda formations are proven, whilst up to 4.5 km across the 2D ultra-deepwater survey the post-rift source rocks are inferred. rock intervals throughout CGG’s 2D seismic dataset. Our from key well logs (i.e. density, P-wave velocity and S-wave that CGG acquired in 2018.  e section is particularly data suggest that the inferred Albian source rock is con ned velocity).  is was used to test that the AVA response important as it provides the overburden necessary to 2D Seismic Data Observations within small half grabens formed in Aptian-age crust, whilst calculated at the wells matches our seismic observations mature the inferred, underlying source rocks.  is Underlying what we interpret as an Eocene–Oligocene the Cenomanian–Turonian source rock interval is a much further o shore. interval also contains key proven seal and reservoir unconformity there is a package of undulating, broader regional feature. Synthetic AVA curves were modelled for the top of the units, as well as a direct hydrocarbon indicator, in the continuous, parallel re ectors that onlap against a main Cenomanian–Turonian source rock for two wells. form of a Bottom Simulating Re ector (BSR). prominent unconformity surface. From our previous Reducing Uncertainty  e results clearly demonstrate the anticipated Class IV As discussed in our previous article Exploring the studies, this lower unconformity surface allows us to Studies of Jurassic source rocks from the North Sea anomaly, similar to previous work on Type II Jurassic source Last Frontier: O shore South Gabon (GEO ExPro 2019, date the package to the Cenomanian–Turonian, an (Løseth et al., 2011) have proven that the tops of organic- rocks in the North Sea.  e slight variations observed Vol. 16, No. 5), explorers have traditionally targeted interval in which the inferred Azile and Cap Lopez rich shales can exhibit Class IV Amplitude Versus O set can be attributed to facies changes in the overburden and post-rift source rocks are (AVO) anomaly responses, producing a large decrease of di erences in average TOC over the bulk of the source rock located. With the same impedance at zero o set that dims with increasing o sets. interval itself. (Top) AI vs TOC plot for the Cenomanian–Turonian source rock interval; (bottom) AI vs TOC plot for Albian source rock interval; (inset) AI vs TOC (Løseth) et al., 2011. seismic stratigraphic  e e ect of this is noticeable with as little as 2% Total approach, we are able to Organic Content (TOC). During CGG’s most recent studies Implications for Inferred Distal Sources High

CGG identify the Albian Madiela o shore Gabon, it was noted that similar e ects were With the rock physics models extracted from wells that Formation which also has visible in the distal seismic data, at the level of the inferred penetrated the source rock intervals, we can now look back potential as a source rock. source rock intervals. at our seismic data to search for a similar response.  e

Al No well data are available It is also worth noting that the Jurassic source rocks intervals mapped as the Cenomanian–Turonian and Albian ) 2 to make a direct tie to studied by Løseth et al. consist of a typical Type II kerogen sequences show both a prominent AI decrease through the these formation markers mixture of degraded terrestrial and planktonic marine top re ection and a clear Class IV AVA anomaly, as illustrated 0% TOC 20% in the main 2D seismic origin.  ese were deposited in a similar deepwater in the seismic foldout and insert on the previous page.  ese survey area, but there marine environment to the Cenomanian–Turonian source results support the potential presence of good-quality source

Al (ms * g/cm Al are known calibration rocks encountered o shore Gabon and, based on their rocks at these levels. Given that deepwater marine conditions points further to the east geochemistry, they are also commonly classi ed as Type II. prevailed throughout the region during the deposition of the where selected lines were Hence, the work from Løseth et al. provides a good analogue. Cenomanian–Turonian, it is a fair assumption to extrapolate Low extended for that purpose In order to validate our seismic observations the the response modelled from proximal wells to the more 0% TOC 4% (see map on main foldout Jeannette-1, Ika Marine-1 and Aulica Marine-1 wells distal areas where our 2D seismic data are located. However, High page). were used to investigate the relationship between extrapolation of the Albian source rock information is more In addition to acoustic impedance and TOC.  is con rmed an inverse speculative because shallower marine settings prevailed in stratigraphic relationships, relationship between measured TOC and Acoustic the inboard locations of the well control at the time. As a a bright, continuous Impedance (AI) for Cenomanian–Turonian and Albian result, the wells used for the rock physics models may not ) 2 negative amplitude source rocks o shore Gabon, in line with the analogue be representative of the more distal marine depositional re ector (indicative of provided by Løseth et al. Both intervals display inverse environment that prevailed over the 2D seismic survey area. a signi cant decrease power trends, but the mudstone-dominated Turonian Azile  e  ndings of our work show how targeted 2D seismic of impedance) exists at and Cenomanian Cap Lopez formations provide a closer data acquisition, combined with geological and rock

Al (ms * g/cm Al the level of all inferred  t than the diagenetically altered carbonates of the Albian physics studies, can provide a low-cost, powerful tool for source rock markers. Madiela Formation. explorationists to reduce the uncertainty associated with  is characteristic, along To provide further support for these observations, a series both source rock presence and quality in unexplored areas, Low with pre-stack seismic of synthetic Amplitude Versus Angle (AVA) curves were such as the ultra-deep waters o shore Gabon. attributes, helped us to produced to model the response of the top of the source 0% TOC 8% trace the potential source rock interface based on rock physics properties extracted References available online.

GEOExPro October 2020 67 68 GEOExPro October 2020 GEOExPro October 2020 69 Exploration A Global Exploration Hotspot New pre-salt opportunities have been identifi ed in the ultra- WEI MINGCHI, SHI KUITAI and deepwater areas of the Santos Basin. GAO JING, BGP

In the past decade, a large number of major discoveries have been Large Pre-Salt Prospects made in pre-salt plays in deepwater areas of the Santos Basin. During 2016 and 2018, BGP in partnership with Spectrum Th ese highlight the outstanding world class exploration potential (now TGS) acquired multiclient 2D seismic data in the remaining within this basin, where the discovered fi elds have an outboard south-eastern part of this oil province in the ultra- average reserve of more than 1 billion barrels of oil, making the deepwater areas of the Santos Basin, as shown on the map Santos Basin an important global exploration hotspot. below. Th e survey consisted of 25,000 km of long-off set high resolution seismic data with 12 km streamer length and 15 Geological Setting seconds recording length, which is designed to improve the Th e Santos Basin is located in the south-east of Brazil deep imaging. Pre-stack time migration (PSTM) and pre-stack and covers an area of 320,000 km2. It is a typical passive depth migration (PSDM) were undertaken and the results continental margin basin and is acknowledged as one of the have been available since early 2019. most prolifi c hydrocarbon-producing basins in the world. Th is survey was designed to make up for the shortage of Th e formation of the Santos Basin is related to the seismic data in the ultra-deepwater areas in the Santos Basin, breaking-up of Gondwana continent and the expansion of by providing high quality seismic data to identify favourable the Atlantic Ocean, which has been taking place since the pre-salt plays. Th e survey area is believed to hold tremendous Mesozoic. Th e tectonic evolution of the basin can be divided hydrocarbon potential and is expected to share the same play into three stages: intracontinental rift, intercontinental rift elements as those associated with discoveries in the known and a passive continental margin stage. Th ese three periods Santos Basin oil province. of tectonic evolution correspond to three major depositional Based on a comprehensive analysis on the discovered sequences found in the basin. Th ese are the continental oil province in the deepwater Santos Basin, a number of sequence of the Guaratiba Group, which was deposited during conditions have been identifi ed as crucial for pre-salt plays the rift period; the Ariri Group salt rock sequence, which in the basin. Th ese include an excellent salt cap rock, high accumulated throughout the transitional period; and fi nally quality source rocks and large carbonate anticlines. the marine sequence of continental margin carbonate and Combining both regional geological information and this deepwater shales and turbidites, which developed during the new seismic data, comprehensive evaluation work has been drift period. carried out and the distribution of pre-salt play elements in BGP-TGS multiclient 2D seismic survey. BGP/TGS

70 GEOExPro October 2020 BGP/TGS ultra-deepwater areas of the Santos Basin have been identified. Aptian salt is found to be widely developed and is very thick over much of the area: up to 4 km in places, although gradually becoming thinner and eventually disappearing when it reaches the south-eastern edge of the basin. This thick and continuous salt is an excellent cap rock for pre-salt traps. The same set of lacustrine source rocks is developed in the survey area as in the oil province. This oil-prone Seismic section from BGP-TGS multiclient 2D seismic data. Barremian source rock is verified by wells with TOCs of 3–6% and kerogen of type I. Large rift this multiclient 2D seismic data will provide support for oil sedimentary depressions that are thought to contain this companies looking for exploration opportunities in the ultra- lacustrine source rock are recognised in the survey area, and deepwater areas of the Santos Basin. these could provide high quality oil and gas source kitchens. Carbonate reservoirs beneath the salt are shown as Significant Discoveries to Come? relatively strong events on seismic sections. A large number of This brief overview shows that the ultra-deepwater of the untested Aptian lacustrine carbonate anticlines with four-way Santos Basin is a frontier area over which there was very dip closures – the main target for exploration in much of the little seismic information until the BGP-TGS multiclient Santos Basin – have been recognised in the survey area, and 2D seismic surveys, the data from which will help favourable analogues with pre-salt plays are identified on interested parties to gain a comprehensive understanding seismic, as seen on the image above, highlighting the great of the region. The survey area shows great hydrocarbon potential for oil and gas exploration that this area possesses. potential and is an excellent exploration opportunity for oil Many oil giants, such as Total, Shell, Chevron and BP, companies, as a large number of pre-salt leads have been entered the blocks in the 16th licensing round in 2019. The identified from this data. It will provide insight into this 17th licensing round scheduled for 2020 was delayed by the undrilled province and support oil companies entering into Covid-19 pandemic and will now take place in 2021 and blocks in future licence rounds.

GEOExPro October 2020 71 GEO Media Geological Tours of North

America’s Wonders THOMAS SMITH

Geologic Tours of the World Th e city of Golden and the Colorado illustrated and explained. Th us far the North America’s Natural Wonders (Two- School of Mines is the fi rst stop. Gary route has taken us up to Stop 4 of a Volume Set) off ers some interesting titbits about transect that continues west through By Gary L. Prost Golden and describes how Denver beat mining towns, across the Continental CRC Press 2020 it to become the territorial capital. He Divide, to hot springs and fi nally gives details on how and when to visit ending up at the Book Cliff s near Grand Detailed, yet nontechnical, these the Mine’s incredible Geology Museum. Junction after another 19 stops and a geologically oriented tours of some of Leaving Golden on I-70, we take a 17 number of side trips. I have driven this North America’s most iconic landscapes minute (11.8 km) side trip along the same route several times; my next will will certainly satisfy the most ardent Dakota Hogback to Red Rocks Park. be with this remarkable book at my side. geoscientist as well as the curious Photos and cross-sections through the layman. Rocky Mountain front help explain the Content When I fi rst received these two type of forces that formed this range Th e book comprises two volumes. volumes, I was delighted to see as compared to some other areas he Volume 1 covers the Canadian Rockies, that I have taken many of the tours covered across Idaho, Wyoming and the California, the Southwest, Great Basin, represented here, and Tetons-Yellowstone as well as having Country. Trips include written about some iconic stops in Banff of the places for GEO National Park, Alberta, ExPro. Th us, being Canada; the California very familiar with a wine country and gold lot of the material I fi elds; the Grand Canyon expected this to be a of Arizona; Zion, Bryce, good review of things Arches, and Canyonlands I already knew. Boy, of Utah; the impressive was I wrong! Th ese Grand Tetons of Wyoming volumes are fi lled and the geysers and hot with photos, maps, springs in Yellowstone geology, history, and National Park. details that would take Volume 2 covers the considerable time and Appalachians, Colorado eff ort to track down Rockies, Austin-Big Bend for just one small area. Country and the Sierra Gary has done that for Madre in northern Mexico. us across some of the most interesting Canadian Rockies. Th is is all explained Trips detail the Central Appalachians and exposed geological features in in a manner that just about anyone with in Virginia and West Virginia, Carlsbad North America. a curious mind can understand. Caverns in New Mexico, Big Bend in One of the highlights of these West Texas, Garden of the Gods, Aspen An Example Transect books has to be the way Gary has used and the Maroon Bells in Colorado, and Tour 3, for example, will take us from excellent photos along with cross- the giant salt-cored uplifts of the La Denver, Colorado to Grand Junction, sections and very understandable Popa Basin of Mexico. Colorado. Gary starts out with an explanations of just what is happening Along with all the iconic areas overview of the entire transect giving geologically. For example, along this detailed above, an impressive number the reader an opportunity to see this fi rst side trip to Red Rocks Park he has a of lesser-known but very interesting great country and what to expect along photo of the Great Unconformity where geological features, history, and other the way. An itinerary from beginning a plaque marks a place where you can titbits will surely keep us all entertained. to end, including stops and side trips, reach across a time gap of 1.4 billion A map at the beginning of both volumes is listed. For this transect, he describes years. From the image of dinosaur shows where each transect is located the geology and geological history of tracks at Dinosaur Ridge to the photo and labels each as to the volume and the Denver Basin including information of the famous I-70 road cut through transect number. All this makes it easy about the area’s mineral resources. the Dakota Hogback, all are brilliantly to plan your next road trip.

72 GEOExPro October 2020 GEOExPro October 2020 73 Exploration Update Brought to you in association with NVentures. Vietnam: New Offshore Gas Play Eni, with partner Essar E&P, has appraised a large gas find with the Ken Bau-2X well in Block 114, offshoreVietnam . The well was drilled

2 km away from the discovery well Ken Bau-1X in 95m of water and NVentures reached a TD of 3,658m in July 2020. Gas pay in excess of 110m was logged in several intervals of Miocene sandstones. Eni carried out ‘mini’ DSTs as well as the usual logging and fluid samples. The results of these suggest initial in-place volumes of between 7 and 9 Tcfg, along with an impressive 400–500 MMb condensate. The 1X discovery well was reported to have TD’d early, due to technical problems, and deeper targets were due to be drilled, but the TD of the 2X well suggests it is only 52m deeper. The partners intend to continue the appraisal drilling as far as possible, considering Covid-19 restrictions. The group also have a second prospect, Dan Day, they plan to drill in due course on the same block. The discovery lies within the Song Hong Basin, and Eni also have 100% of Block 116 immediately to the south, where they are carrying out seismic surveys. Eni reports that Vietnam is experiencing increased gas demand, for both domestic consumption and GTP, and are planning LNG imports, so the discovery comes at a good time for both operator and host government. Kris Energy, operator of the block east and adjacent to Block 115, might have expected a fillip in its fortunes with this news of nearby large gas reserves, but having suspended trading since August 2019 and entering into a 100% farmout on the block to an undisclosed company (possibly Eni), the firm may not benefit from this drilling campaign.

South Africa: Once More into the Deep!

Total, with partners Africa Energy, and CNR, have returned to the deepwater Block 11B/12B offshoreSouth Africa to spud the Luiperd-1 well. The wildcat is a long-anticipated sequel to NVentures Brulpadda, which opened up the large Paddavissie mid-Cretaceous submarine fan play in 2019. Apart from the usual subsurface challenges of finding large clastic reservoirs with a high chance of hydrocarbon pay, this play has further natural met-ocean hurdles in the form of currents and swell that challenge even the most advanced drilling rigs (Brulpadda itself was abandoned on the first attempt in 2014 under difficult drilling conditions). In this case Odfjell’s Deepsea Stavanger is rising to the challenge, having successfully completed the Brulpadda discovery last year. This play-opening gem logged 34m of gas condensate and oil pay in mid-Cretaceous high net-to-gross (N/G) sands, and 23m gas condensate in the Lower Cretaceous with similarly high N/G and without encountering an oil-water contact. Furthermore, the well appears to have lit up the Paddavissie AVO trend, with Luiperd one of four main targets, the others being Blassop and Woudboom. Partners on the licence have released various updates, suggesting the Luiperd prospect could be 50% larger than Brulpadda. Overall this play could prove up over 1 Bboe in basin floor Cretaceous fans on this passive margin, finally delivering on the Jubilee promise of 2007. In the adjacent South Outeniqua Block, Total is scoping a proposed work programme of drilling, VSP and CSEM, with reports of up to ten possible further wells. Elsewhere in South Africa, Equinor and ExxonMobil recently exited the country, possibly for above-ground as well as geological risk reasons, although Shell has strengthened its position, having bought Kosmos’ share in the ultra-deepwater North Cape Block. Total maintain a strong acreage position from here north-west all the way to the border with Namibia, and also hold large blocks offshore southern Namibia.

74 GEOExPro October 2020 Turkey: A Prize Catch in the Black Sea

In Turkey the state oil and gas firmTPAO has announced a major gas discovery at Tuna-1 in the western Black Sea. The firm was drilling in 2,115m water depth on the Sakarya licence (Blocks C26, C27, D26 and D27) between July and August 2020. TPAO claim the discovery shows potential for an impressive 11.3 Tcf of lean gas (in- NVentures place), which would be the largest-ever gas discovery in the Black Sea and make Turkey self-sufficient in gas over the next decades. Given plans for further drilling in this area, along with a major campaign offshore southern Turkey and Cyprus, the country could swing the pendulum towards having major influence over the gas export and transit policies of eastern and southern Europe and North Africa, a role Ankara appears to be very enthusiastic about. As Greece struggles to make important strides on their deepwater acreage (Repsol, Total and ExxonMobil are either being restrained or showing restraint in kicking off their campaigns offshore Greece and Crete), Turkey, Israel and Egypt will vie for dominance in supplying an ever-richer gas mix into the heated European markets. The Tuna-1 discovery well penetrated over 100m gas column in Mio-Pliocene sandstones, trapped in a major fan system probably draped over a broad compression ridge, 60 km from the Domino gas discovery in the Romanian sector of the Black Sea. TPAO will appraise it with blockwide 3D seismic ahead of drilling, aiming for first gas in 2023. Turkey has the longest coastline on the Black Sea and controls the largest offshore portion of the Exclusive Economic Zone. Since 2004 the state NOC has sponsored over 50,000 km of 2D and 14,000 km2 3D as operator or JV partner. In 2013 TPAO mobilised the Leiv Eiriksson drillship after OMV and ExxonMobil discovered gas at Domino in the Bulgarian sector. Only now, with a state-owned drillship Fatih, have they been able to venture beyond 2,000m water depth and test deeper Miocene targets. TPAO have said previously they believe the Turkish sector of the Black Sea can hold up to 53 Tcfg (GEO ExPro Vol. 10, No. 1, 2013), leaving Ukraine, Georgia, Romania and Bulgaria to catch up.

GEOExPro October 2020 75 FlowBack

Big Oil Needs Big Data Conversion Factors

While gathering my thoughts for FlowBack, two pieces of information recently Crude oil fl ashed across my screen. First came the news that BP CEO Bernard Looney will 1 m3 = 6.29 barrels again be a keynote speaker at next year’s International Petroleum (IP) Week in 1 barrel = 0.159 m3 London and then, perhaps predictably, we heard that the event will be digital. Mr 1 tonne = 7.49 barrels Looney, no doubt, will stare out of our computer screens and tell us more about his company’s transition to meet net carbon zero by 2050. He will also give us Natural gas more words of wisdom on the industry’s transition in areas like carbon intensity, 3 3 diversifi cation and indeed the digital arena. 1 m = 35.3 ft Data mining and data analytics are both buzz terms in the industry. Geologists 1 ft3 = 0.028 m3 and engineers now know more about oil prospects than ever. Decisions are backed by hard evidence, whatever the uncertainties of the global economy. It is a bit like Energy governments around the world six months into the pandemic. Th ey still have to 1000 m3 gas = 1 m3 o.e. make challenging decisions involving brakes and accelerators, but they are better 1 tonne NGL = 1.9 m3 o.e. informed about what will happen if diff erent courses of action are followed. By the same token Mr Looney and his fellow ‘’ CEOs feel better informed about what they need to do. Th ey have the time and the reserves – even the Numbers will – to turn their tankers around, although smaller companies may go to the Million = 1 x 106 wall. Mr Looney, we are to understand, believes in clean energy and thinks it is a Billion = 1 x 109 lucrative market. How he is going to get there is less clear. Trillion = 1 x 1012 In the short term at least, there is no shortage of mixed messages. At the time of writing the oil price is up above $40 a barrel but the pandemic still rages. A recovering oil price will bring more assets back into play but, to quote immediate Supergiant fi eld history, Rystad Energy reminds us that Covid-19 has brought about a 20% reduction Recoverable reserves > 5 billion in economically recoverable oil. Th is brings us back to the beauty of sound data barrels (800 million Sm3) of oil analysis and science-based decision-making. As the geologist Catriona Penman equivalents notes in a recent article in World Oil: “With the uncertainty caused by Covid-19, the decision to bring back a shut-in well, or begin producing a drilled-but-uncompleted Giant fi eld well, will require a heightened level of analysis.” Even in the six years since the last oil price crash, visualisation technology Recoverable reserves > 500 million underpinned by sophisticated data analytics has improved exponentially. Concepts barrels (80 million Sm3) like digital twinning add a new dimension to the way assets can be modelled over of oil equivalents time. Digital IP Week will remind us remotely of these and other developments. Mr Looney, you could argue, has the perfect platform for making his case. Major fi eld Nick Cottam Bernard Looney, CEO of BP. Recoverable reserves > 100 million barrels (16 million Sm3) of oil equivalents BP.com

Historic oil price Crude Oil Prices Since 1861 NominalNominal RealReal (2014(2014 dollar)dollar) 140

120

100

80

60

40 US Dollars per barrel US Dollars per barrel

20

140 1861 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2016 1861 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2016

76 GEOExPro October 2020 GEOExPro October 2020 77 78 GEOExPro October 2020