Buried treasure Shedding light on alternative deep Earth resources, Professor Ranjith Pathegama Gamage is an expert in fundamental and applied rock mechanics – a key field in the battle to combat climate change – and energy extraction from deep Earth kind in Australia for this specialisation, the significantly reduce permeability in coal Laboratory serves as a national focal point for seams and similar deep Earth porous media. such research. Some of the AUD $18 million- This is a key finding; it opens up new research worth of equipment in DEERL (macroscale directions toward the use of supercritical CO2 PROFESSOR RANJITH PATHEGAMA GAMAGE RANJITH PATHEGAMA PROFESSOR high-pressure testing chambers) is unique in flow through deep underground reservoirs Australia. Monash University has therefore (coal seams, shale basins, saline aquifers and achieved an international reputation as a oil beds). It also promises important advances ‘power house’ of large-scale advanced testing in CO2 injection for enhanced recovery of coal facilities for deep Earth explorations. These seam gas. advanced facilities can be effectively used to conduct research on coal seam gas, shale gas Where are you hoping to concentrate your and deep geothermal recovery under complex efforts over the next few years? geological conditions. Climate change legislation, along with With reference to potential benefits and regulations to limit greenhouse gases, has led limitations, can you discuss carbon capture to natural gas competing with oil and coal; and storage (CCS)? Do you think CCS is ranking now as the third largest of the world’s viable as a large-scale option for climate energy sources. Among these sources, natural change mitigation? gas is the cleanest and most hydrocarbon- What do your current roles as Director rich, and has high energy conversion of Deep Earth Research and the Head of CO2 emissions into the atmosphere due to efficiencies for power generation. Geomechanics Engineering at Monash fossil fuel usage during power generation University entail? and other industrial processes can be largely The greatest challenge is very low recovery of reduced (around 90 per cent) through CCS gas. Because of extremely low permeability The Deep Earth Energy Research group and therefore it is clearly a large-scale option values in shale gas reservoirs, appropriate consists of eight academic staff and for climate change mitigation. However, permeability enhancing techniques are over 30 PhD students and 10 postdocs. predicting the long-term safety of CO2 necessary for adequate recovery. Of all The primary aim of the group is to help storage in oceans or deep underground is these techniques, hydraulic fracturing facilitate collaborative fundamental and still very difficult. That is where my team (hydro-fracturing) of the reservoir rock by applied research on feasibility assessment is placing quite a lot of effort. Our vision injection of high pressure fluid is the most and technical problems that currently is for a future where deep geological CO2 effective and commonly used. However, impede progress in the development sequestration systems provide a fully conventional enhancement of permeability of alternative deep Earth resources. functioning, immediate and affordable option for hydro-fracturing poses significant Such deep Earth resources include new for controlling the impacts of global warming. environmental challenges. low-emission hydrocarbon alternatives (including underground coal gasification, Are there examples you could provide I want to focus on the development of coal-bed methane, shale gas and tight-sand of your current investigations exploring environmentally friendly techniques for shale gas); renewable energy sources (such as innovative methods to make CO2 gas extraction, through critical experiments geothermal energy); options for geological sequestration more practically viable? in modified hydraulic fracturing. These waste containment (including carbon dioxide innovative techniques (use of waste CO2 as an (CO2) storage and nuclear waste disposal); According to our findings, injection of nitrogen input to the shale gas industry) need in depth and future metals integral to renewable into the coal seam during sequestration research to identify an optimum mechanism energy technologies. will reverse CO2-induced swelling to some with all necessary rigour and clarity. extent (20-30 per cent), which enhances CO2 Can you describe some of the advanced injectibility. In addition, proper control of the experimental facilities at your disposal for injection and production well arrangement deep Earth research? in the coal seam will significantly increase process efficiency. I have established state-of-the-art testing facilities in Monash’s Deep Earth Energy In addition, my group provided the first Research Laboratory (DEERL). The first of its confirmation that supercritical CO2 can 104 INTERNATIONAL INNOVATION PROFESSOR RANJITH PATHEGAMA GAMAGE Deep in thought With the aim of making Australia a world leader in renewable energy technologies and carbon dioxide emission reduction, the Deep Earth Energy Research group at Monash University is developing techniques to both extract energy sources and bury carbon deep underground in a clean, sustainable and environmentally friendly way AT MORE THAN four times the world average, Current objectives include finding the optimum only Bahrain, Bolivia, Brunei, Kuwait and Qatar energy required to initially form network have higher per capita carbon dioxide (CO2) cracks and subsequently extend it, as well as emissions than Australia. Recognising this investigating the rock-fluid interaction, flow and situation, the Australian Government is diffusion in the resulting fractured shale system. providing domestic actions and partnering with other countries to build capacity in NEW MINING TECHNOLOGY order to reduce emissions and adapt to the impact of climate change. However, more The mining industry is seeking innovations in research across a broad range of fields and science and technology in breaking rocks for sectors is required if mitigation strategies, as mineral extractions to meet the world’s growing well as switching coal to natural gas, are to prove energy needs, reduce energy consumptions successful. and minimise environmental impacts. Blasting is currently the common practice for hard rock Led by Professor Ranjith Pathegama Gamage, mining, followed by further crushing. Extraction Professor in Geomechanics and Australian of minerals depends on crushing rock, and Research Council (ARC) Future Fellow in around 6 per cent of Australia’s electricity is Resources Engineering, the Deep Earth Energy consumed in this energy-intensive process. Research group is conducting investigations into Blasting often produces large rock blocks of up both extracting energy – such as oil, coal and to a few metres, leading to complications of gas – from the Earth in a more environmentally handling and secondary blasting. Ranjith aims friendly way and also storing atmospheric carbon to develop new science for a more efficient underground; two essential components of any engineering approach of rock breakage – one serious climate change mitigation strategy. that is environmentally and economically sustainable. ENERGY EXTRACTION SEQUESTRATION Largely triggered by the economic success of US shale gas extraction, many countries including CO2 sequestration involves the collection of the Australia are now exploring the possibility gas in large quantities from fossil-fuel power of tapping into their own reserves. However, plants, and then liquefying and subsequently there are still concerns regarding groundwater storing it, where it will remain for millennia. contamination, earthquakes, use of large However, while the concept is clear, efficient volumes of water and the release of methane sequestration remains incredibly challenging. into the atmosphere. Consequently, Ranjith and his research team have been investigating ways Biological, oceanic and shallow geological to minimise the environmental impact of shale sequestration have all been considered, but it gas extraction and improve its efficiency. is generally agreed that the most promising method is deep geological sequestration in large Current methods use water to fracture shale, underground reservoirs, despite the fact that the but the Monash team is exploring a waterless technique has yet to be proven technically and method, using supercritical CO2 or nitrogen as economically viable. an alternative. Using these non-aqueous fracture fluids could mean reduced contamination and Key to the success of such a technique is the improved extraction efficiency, thus transforming underground reservoir’s ability to effectively shale gas into an economically attractive and, take in and retain CO2. Governed by the importantly, green energy source. characteristics of the material that constitutes Macroscale core Deep geothermal flooding testing rig. testing chamber. WWW.RESEARCHMEDIA.EU 105 INTELLIGENCE numerical modelling have highlighted the sorbed-CO storage capacity of various coal DEEP EARTH ENERGY EXTRACTIONS 2 types. “We were the first to investigate the AND CARBON STORAGE swelling such injection induces in the seams – OBJECTIVES a crucial issue affecting the flow of CO2 and its containment for sequestration,” adds Ranjith. To undertake collaborative fundamental and Largest core applied research on feasibility assessment Their conclusions show that coal seams are and technical problems that currently