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Subsea Pipelines Collaboration Cluster Advancing our knowledge of pipeline technology to support the oil and gas industry

Final report

2 Executive summary 17 Putting the Cluster’s research into practice 4 Introduction to the Subsea Pipelines Cluster 21 Commissioning experimental equipment 6 Training the offshore for ongoing pipeline pipeline engineers testing in Australia of the future 28 Publications and 10 Scientific and dissemination engineering challenges 34 Key papers 12 Scientific outcomes of the Flagship 46 Awards Collaborative Cluster 48 Keynote presentations, invited lectures and papers

49 Hosting international conference ISFOG

50 The Partners

51 Flagship Collaboration fund

1 Executive summary Offshore subsea pipelines are used to export oil and gas from the field to platform and then from the platform to the mainland. As they are the sole conduit for the hydrocarbons their stability and integrity are of critical economic and environmental importance.

More than 80 per cent of Australia’s gas resources exist in deep, remote, offshore areas and being able to realise the full potential of these remote resources relies on the development of economically viable transportation . Technical solutions for Australia’s offshore pipelines must maintain structural integrity and continuous supply of products across hundreds of kilometres of . Such technology is also vital to Australia achieving the vision of “platform free fields”, a CSIRO Wealth from Oceans Flagship initiative. Platform free fields research investigates ways to replace traditional oil and gas platforms with subsea technologies for production of gas resources which may lie as far as 300 km offshore, at a depth greater than 1 km. To address the challenges of providing technical solutions to the Australian oil and gas industry, six universities and CSIRO’s Wealth from Flagship came together in 2008 to establish the Subsea Pipelines Collaboration Cluster. Its goal was to underpin the development of these hydrocarbon resources, by providing engineering solutions for the safe and economic design and operation of subsea pipelines in Australia’s offshore frontiers. This research Cluster was enabled by a $3.6 million grant through the CSIRO Flagship Collaboration Fund and in-kind contributions from the participating universities of $7.4 million. Bringing together an integrated and multi- disciplinary team has been fundamental to the success of the Cluster. The Cluster has resulted in significant advances in the understanding of subsea pipeline technology,

2 Subsea Pipeline Collaboration Cluster – final report including the development of state- The boom in Australian oil of-the-art experimental equipment and gas has caused a skills shortage in to test pipeline attributes. key engineering fields. It is therefore a key achievement that this cluster Key achievements include establishing has also trained 41 offshore engineers new numerical models and software and researchers for the benefit of for analysing the stability of offshore the offshore oil and gas industry pipelines, novel methodologies for through its PhD and postdoctoral economic and safe pipeline design, programs. This will help underpin and the commissioning of world- the future success of engineering class experimental and pipeline in this area of national priority. Mark Cassidy testing facilities. These have resulted in specialist testing and consultancy The Cluster outcomes are helping to Leader services being available to the offshore build future research priorities in CSIRO, CSIRO Flagship Collaboration Cluster on Subsea Pipelines pipeline industry. The increased the Universities and with industry The University of Western Australia knowledge and understanding will partners in the areas of pipeline design contribute to CSIRO’s own research and installation in Australian calcareous in the areas of gas flow assurance soil conditions and in deep water, and production. They are also geohazard , use of publically available with the Cluster automated underwater vehicles and in having published more than 160 developing the vision of platform free manuscripts in international journal fields in Australia. Future activities, such and conference proceedings. as interactive workshops, will build on this successful collaborative relationship. Results from the Cluster’s research has already been incorporated into the This report summarises the next generation of subsea natural gas achievements of the Subsea projects such as the A$43 billion Gorgon Pipeline Collaboration Cluster and Ian Cresswell project in north-west Western Australia its impact on the Australian and Acting Director that involves the development of the international oil and gas industries. CSIRO Wealth from Oceans Flagship Greater Gorgon gas fields and a LNG plant on Barrow Island, near Karratha. Acting for clients BP, Chevron, Inpex and Woodside, testing facilities developed have also underpinned designs for Australia’s future pipelines to the Pluto, Wheatstone, Ichthys and Browse fields (off the north-west Western Australian coast) and in international projects offshore West Africa, Egypt and in the Caspian sea. Research in the cluster also formed part of a joint industry project sponsored by the six energy majors BHP Billiton Petroleum, BP, Chevron, Petrobras, Shell and Woodside, and administered by the Minerals and Energy Research Institute of Western Past CSIRO Wealth of Oceans Flagship Director Kate Wilson (right), CSIRO Energy Executive Australia (MERIWA Project M395). Bev Ronalds (centre) and UWA Vice Chancellor Alan Robson (left) at the Cluster launch

3 Introduction to the Subsea Pipelines Cluster

Building a pipeline system to link an offshore oil and gas field to the mainland represents a huge capital investment. For example, in Australia the construction of the 42 inch 135 km pipeline for the Trunkline System Expansion Project (TSEP) on the North West Shelf in 2003/04 cost approximately A$800 million. Today, the cost per kilometre of current pipeline projects, including the Gorgon (water depth: 1350 m length: 65 and 140 km), Scarborough (depth: 900m length: 280km), Pluto (depth: 830m length: 180km) and Browse (depth: 600m length: 5, 24 and 400km) is estimated to exceed $4.5 million per kilometre. With over 2000km of pipelines under design in Australia, capital expenditure is expected to exceed $10 billion.

With more than 80 per cent of resources which are considered CSIRO, Australian universities and other Australia’s gas resources exist in deep, stranded off our coast in deep water publicly funded research agencies. remote, offshore areas, our ability and at long distances to land. Under The Subsea Pipeline Collaboration to realise their full potential relies these conditions subsea pipelines are Cluster was initiated by the Wealth on the development of economically required to transport the gas over from Oceans Flagship to bring viable solutions to transport them. long distances to shore. Transporting together a diverse range of research hydrocarbons in extra long offshore Such technology is vital to Australia capabilities to deliver an in-depth pipelines poses many challenges that achieving the vision of Platform Free scientific understanding of the must be considered when designing Fields, a CSIRO Wealth from Oceans key parameters involved in subsea pipelines. These include stability of Flagship program. This research pipeline design, construction, long- pipeline structures over decades in investigates ways to replace traditional term operation and monitoring. strong currents, a shifting seabed and oil and gas platforms with subsea on steep seabed slopes. Assessment The three year program contributed technologies for production of gas and mitigation of potential geohazards, to CSIRO’s research program that aims such as submarine landslides, is also to work with industry to develop the critical for the safe routing of pipelines. science and technology to unlock new opportunities in the exploration and The Subsea Pipelines Collaboration development of Australia’s offshore Cluster was established to meet hydrocarbon resources. The $7.4 these challenges and to deliver million Cluster included $3.6 million science-based engineering solutions from the Flagship Collaboration Fund for the safe and economic design and $3.8 million in-kind contributions and operation of subsea pipelines from the participating universities. in Australia’s deepwater frontiers. Research has focused on ultralong The Subsea Pipeline Collaboration pipelines from deepwater to shore, a Cluster combined the research critical goal of Platform Free Fields. capabilities of The University of Western Australia, Curtin University The CSIRO Flagship Collaboration of Technology, The University of Fund enables the skills of the wider Queensland, Monash University, The Australian research community to University of Sydney, Flinders University be applied to the major national and CSIRO through the Wealth from challenges targeted by CSIRO’s National Oceans National Research Flagship. Research Flagship Program. As part of From a start of 17 Chief Investigators the the $480 million provided over seven cluster grew to eventually encompass years by the Australian Government 31 academic researchers and another to the National Research Flagships, 27 PhD and Masters students. $115 million was allocated specifically to enhance collaboration between

4 Subsea Pipeline Collaboration Cluster – final report CSIRO Cluster on Subsea Pipelines Participants

SEABED SEABED MORPHOLOGY PIPELINE RELIABILITY CHARACTERISATION Lead Researcher Lead Researcher Lead Researcher Professor Liang Cheng Professor Hong Hao Professor Mark Randolph Researchers Researcher Researchers Dr Ming Zhao Professor Mark Cassidy Professor Liang Cheng Dr Zhipeng Zang Dr Ying Wang Professor David White PhD Students PhD Students Professor Mark Cassidy Di Wu Xuelin Peng Dr Itai Einav Siti Fatin Mohd Razali Chunxiao Bao Dr Pierre Rognon Fang Zhou (Visitor) Wang Chao (Visitor) Dr Noel Boylan Xiaosong Zhu (Visitor) Dr Hongxia Zhu PhD Students Han Eng Low AUV AND ROV-BASED Zhihui Ye PIPELINE SYSTEMS FOR PIPELINE Yan Yue Lead Researcher MONITORING Hamed Mahmoodzadeh Professor David White Poornaki Lead Researcher Researchers Associate Professor Professor Liang Cheng Karl Sammut Professor Mark Randolph Researchers STRUCTURAL Associate Professor Yuxia Hu Dr Tom Baldock Associate Professor Fangpo He INTEGRITY Dr Christophe Gaudin Dr Jimmy Li Dr Kim Klaka Lead Researcher Dr Nathalie Boukpeti Dr Alec Duncan Professor Mark Cassidy Dr Dong Wang Dr Noel Boylan Mr Andrew Woods Researchers PhD Students Professor Xiao-Ling Zhao PhD Students Andrew Lammas Professor Jayantha Kodikara Jaya Kumar Seelam Matthew Kokegei Dr Faris Albermani Hee Min David Robert Dr Yinghui Tian Indranil Guha Tae-hwan Joung Professor Mark Randolph Fauzan Sahdi Lyndon Whaite Professor David White Grant Pusey Dr HongBo Liu Dr Zhigang Xiao (until 2009) Dr Pathmanathan Rajeev PhD Students Mehdi Golbahar Matthew Hodder Bassem Youssef Senthilkumar Muthukrishnan Hossein Khalilpasha

5 Training the offshore pipeline engineers of the future The Subsea Pipeline Collaboration Cluster is not only devising tomorrow’s subsea pipeline technology, it is providing significant research training for Australia’s future pipeline engineers. In all, 27 PhD students and 14 research associates undertook pipeline research within the cluster.

6 Subsea Pipeline Collaboration Cluster – final report Chief Investigators

The University of Western Australia The University The University Curtin University of Sydney of Queensland of Technology

Mark Cassidy Hong Hao

Itai Einav Faris Albermani Kim Klaka

Monash University

Mark Randolph Liang Cheng

Tom Baldock Alec Duncan

Flinders Xiao-Ling Zhao University

David White Christophe Gaudin

Andrew Woods

Fangpo He

Jayantha Kodikara

Jimmy Li

Karl Sammut

7 CSIRO Cluster Postdoctoral Research Associates

Name Institution Project Where they are now? Hongjie Zhou University of Western Australia Seabed Characterisation Advanced Geomechanics Pierre Rognon University of Sydney Seabed Characterisation University of Sydney Noel Boylan University of Western Australia Seabed Characterisation Advanced Geomechanics Pipeline Hazards Yinghui Tian University of Western Australia Structural Integrity University of Western Australia Zhigang Xiao Monash Structural Integrity Monash University Pathmanathan Rajeev Monash Structural Integrity Monash University HongBo Liu Monash Seabed Integrity Monash University Ming Zhao University of Western Australia Seabed Morphology University of Western Sydney Zhipeng Zang University of Western Australia Seabed Morphology Nathalie Boukpeti University of Western Australia Pipeline Hazards University of Western Australia Dong Wang University of Western Australia Pipeline Hazards University of Western Australia James Schneider University of Western Australia Pipeline Hazards University of Wisconsin-Madison Ying Wang University of Western Australia Pipeline Reliability Shanghai Jiao Tong University Andrew Lammas Flinders Pipeline Monitoring Flinders University

8 Subsea Pipeline Collaboration Cluster – final report CSIRO Cluster Postgraduate Student Participants

Name Inst. Thesis Title Cluster Stream Name Inst. Thesis Title Cluster Stream James Schneider UWA Analysis of piezocone data for displacement pile design Pipeline Hazards Hongije Zhou UWA Numerical study of geotechnical penetration Seabed Characterisation problems for offshore applications Han Eng Low UWA Performance of penetrometers in deepwater soft soil characterisation Seabed Characterisation

Matthew Hodder UWA Geotechnical analysis of offshore pipelines and steel catenary risers Structural Integrity Di Wu UWA Experimental and numerical modelling of natural backfill Seabed Morphology of navigation channels and pipeline Grant Pusey Curtin Characterisation of long-range horizontal performance Pipeline Monitoring of underwater acoustic communication Siti Fatin Mohd Razali UWA Wake characteristics of yawed circular cylinders and suppression Seabed Morphology of vortex-induced vibration using helical strakes Xuelin Peng UWA Condition monitoring of offshore pipelines using vibration based method Pipeline Monitoring Jaya Kumar Seelam UQ Tsunami induced bed shear stresses- project 4 Pipeline Hazards Benham Shabani UQ Ben contributing to the modelling of Jaya's but PhD otherwise unrelated Pipeline Hazards Andrew Lammas Flinders 6 Degree of Freedom Navigation Systems for Pipeline Monitoring Autonomous Underwater Vehicles Matthew Kokegei Flinders Fully Coupled 6 Degree of Freedom Control Systems Pipeline Monitoring for Autonomous Underwater Vehicles Yan Yue UWA Novel methods for characterising pipe-soil Seabed characterisation interaction in-situ in deep water Bassem Youssef UWA Use of probability models in the integrated analysis in offshore pipelines Structural Integrity Zhihui Ye UWA Erosion threshold and erosion rate of seabed sediments Seabed Characterisation Santiram Chatterjee UWA Modelling of pipeline seabed interactions Seabed Characterisation David Roberts Flinders Pipeline Tracking Using Scanning Imaging Pipeline Monitoring Tae-hwan Joung Flinders Computational Fluid Dynamics Modelling Techniques for Pipeline Monitoring Analysing the Performance of a AUV Thruster Lyndon Whaite Flinders Mesh Free Methods for Probabilistic Optimal Control and Pipeline Monitoring Estimation of Autonomous Underwater Vehicles Fauzan Sahdi UWA Modelling of submarine slides and their impact on pipelines Pipeline Hazards Amin Rismanchian UWA Three dimensional modelling of pipeline buckling on soft clay Seabed Characterisation Senthilkumar Monash Offshore pipe clay seabed interaction in axial direction Structural Integrity Muthukrishnan Chunxiao Bao UWA Vibration based structural health monitoring Pipeline Reliability of onshore and offshore structures Indranil Guha UWA Structural analysis of submarine pipelines under Pipeline Hazards submarine slide and thermal loading Hossein Khalilpasha UQ Propagation buckling of deep subsea pipelines Structural Integrity Hamed Mahmoodzadeh UWA Interpretation of partially drained penetrometer tests with Seabed Characterisation Poornaki applications to the design of spudcan foundation Hassan Karampour UQ Coupled upheaval/lateral and propagation buckling of ultra-deep pipelines Structural Integrity

9 Scientific and engineering challenges The Subsea Pipeline Collaboration Cluster investigated and developed scientific solutions to overcome the challenges of constructing pipelines from oil and gas reserves in water depths exceeding 1000 metres.

For safe and economic developments ◆◆design for future pipeline design projects, such pipelines are required to ◆◆construction with particular relevance to remote maintain their structural integrity and offshore locations around Australia. long-term operation continuously supply hydrocarbons ◆◆ There were six research streams across hundreds of kilometres of ◆◆real-time monitoring. which mimicked the life cycle of a rugged, often shifting, seabed to The aim of the program was to provide pipeline, from characterising the bring the hydrocarbons to shore. a technical basis for the design of design environment to monitoring pipelines for any new offshore field, The Cluster brought together a diverse any risk of failure during operation. which contrasts with the current range of research capabilities to deliver case-by-case approach, significantly These streams were: an in-depth scientific understanding reducing costs and uncertainties of subsea pipelines in the areas of:

10 Subsea Pipeline Collaboration Cluster – final report Seabed characterisation This project concentrated on advanced testing of seabed sediment characteristics to understand how they may affect pipelines resting on the seabed. Current methods practised in industry are hampered by the expense of having to conduct multiple tests along a long pipe route, inaccuracies in interpreting site-characterisation tools developed for traditional deep Pipeline stability studies in Sea-bed amplitude map showing features foundation rather than the top 1 m layer the miniature O-tube of the Gorgon slide, North West Shelf of soil, and difficulties of collecting soil samples for onshore laboratory testing. Full-life reliability Novel equipment and interpretative Structural integrity methods were developed to define This project developed new numerical This research assessed the feasibility of the main engineering parameters models and design frameworks for using vibration measurement to monitor required for pipeline design, such as the analysis of pipeline stability and the health of pipelines, with the aim seabed strength and the effects of fatigue by integrating the interactions of replacing expensive and irregular seabed erosion. These included the and effects of the seabed, currents visual monitoring with continuous piezoball, toroidal and hemispherical and on the pipeline structure. measurements and analysis. Both shallow ball penetrometers. numerical simulation and experimental Pipeline hazards test results indicate that vibration measurement is very sensitive to Deep-water developments require pipeline scouring damage. Methods pipeline routing up the continental were developed for possible applications slope in areas of changing seabed to monitor pipeline conditions online. morphology and other geohazards. One key technical challenge addressed by the Pipeline monitoring Cluster was the impact of a submarine landslide sliding down the continental Research explored the use of slope and colliding with a pipeline. autonomous underwater vehicles Based on physical and numerical (AUVs) for continuous monitoring, modelling, this research developed assessment of pipeline integrity and UWA miniature piezoball new calculation methods and analysis evaluation of the seafloor, and the tools. These tools were used to model autonomous operation of an underwater Seabed morphology the run-out of submarine slides and to communication link between acoustic Research was conducted into the assess their consequent impact forces modems. The scope of the AUV work formation mechanisms of seabed sand and potential damage to submarine included developing new navigation, waves and in developing a model to pipelines, together with an assessment control, and guidance techniques. predict the evolution of sand waves with of tsunami-induced bed shear stresses These new techniques aimed to improve and without the presence of a pipeline. and gradients on the sea floor. a vehicle’s capability to move more The project developed methods to accurately over long distances while predict the three-dimensional erosion working close to objects; to detect and of the seabed under pipelines. track pipelines; and to manoeuvre to deploy instruments into the seabed. The technical detail and major outcomes will now be presented for each of these research streams.

11 Scientific outcomes The following are the major scientific outcomes of the Subsea Pipeline Collaboration Cluster

◆◆Development of novel penetrometers and techniques for interpreting soil properties, including an enhanced ball-shaped penetrometer – the piezoball – and new toroidal and hemispherical devices for deployment at the seabed. These devices are already being used in practical applications offshore, where they are deriving soil properties in the upper metre of soil, the most relevant part of the seabed for pipeline design. ◆◆Development of a methodology for interpreting pipeline axial friction design values from novel toroidal and Piezoball testing in Trondheim – (from left) Noel Boylan (formerly COFS), Mike Long hemispherical penetrometer results. (UCD), Annika Bihs (NTNU), Jan Jønland (NTNU) and Roselyn Carroll (UCD)

◆◆Complementary geotechnical ◆◆Established new solutions for the centrifuge and field testing of the interactive forces between pipelines piezoball penetrometer at UWA, the and the seabed during axial and lateral Riverside site in East Perth and the movement, on both coarse-grained Kvenild and Dragvoll sites in Norway and fine-grained , with these (the latter in collaboration with the solutions being encapsulated into an Norwegian University of Science and efficient macroelement framework. Technology). The tests examined the transition between intact and Miniature piezoball in beam centrifuge remoulded shear strength, as well as dissipation tests to examine the consolidation properties of the soil. Both are essential in the interpretation of seabed properties for design of deepwater pipelines. ◆◆Proposed interpretative method for adjusting measured piezoball resistance to allow for the effects of partial consolidation.

Distribution of excess pore pressure after a 3-diameter penetration

12 Subsea Pipeline Collaboration Cluster – final report u and uumball (kPa) (a) u/D = 0.1    Piezocone Piezoball

(b) u/D = 0.5

Depth (m) 

 u0

 (c) u/D = 1 Bq and Bumball Softening . . . factor 1.00 0.95 0.90 0.85 0.80 0.75 (d) u/D = 7 0.71 0.66 0.61 0.56 0.51 Depth (m)  0.46 0.14 0.36 0.31 

 Profiles of (a) 2u and umball (b) Bq and Bmball

13 (a) (b)

Example of video footage images of (a) a pipeline crossing a sleeper and (b) an as-laid survey in silt

◆◆Established framework for ◆◆Development of a numerical ◆◆New convolution models to incorporating macroelement pipe- model that simulates sand calculate total bed shear stresses seabed models into structural formation and evolution. for solitary waves and breaking analysis programs, including tsunami wave fronts. ◆◆Verification of the Regional uplift and reattachment. Oceanographic Modelling System ◆◆Establishment of state-of-the- ◆◆Extension of plasticity models (ROMS) model for sand wave art experimental equipment for describing the pipe-soil load migration and sand wave-pipeline ongoing testing to support the displacement behaviour on interaction model against offshore design of Australia’s offshore Australia’s calcareous sands to lateral data and comparison of numerical pipelines, including: displacements of up to five diameters. results to other published models. – the world’s first facility ◆◆Development of numerical analysis ◆◆Establishment of a numerical for simulating submarine code for integrated storm loading model for three-dimensional slides at small scale within a on on-bottom pipelines. flow and scour under pipelines, geotechnical drum centrifuge and subsequent validation of the ◆◆Proposed formulae to calculate the – a pressurised testing vessel of 4m model against experiments. natural frequency of free spanning length and 173mm internal diameter subsea pipelines by considering ◆◆Analysis of initial embedment and that is rated for 20MPa and capable the boundary conditions, mass subsequent axial displacement of simulating the propagation of hydrocarbon products, axial coupling pore pressure dissipation of pipeline buckling during deep and multiple spans. and soil deformation. water installation and operation (up to 2000m water depth) ◆◆Development of numerical analysis ◆◆Analysis of the influence of boundary using boundary element method conditions, hydrocarbon products and to predict the fatigue life of subsea axial pipeline tension on the natural pipelines subject to combined actions. frequency of on-bottom pipelines.

14 Subsea Pipeline Collaboration Cluster – final report – development of capabilities for attitude, velocity, and rotational simulating whole-life loading rates, as well as water currents histories on model pipes in the acting on the vehicle geotechnical centrifuge, including – a fully-coupled control algorithm storm-induced hydrodynamic to achieve improved manoeuvring load sequences, and thermally- close to hazards and reduce induced lateral buckling cycles battery consumption – development of miniaturised – a pipeline tracking system that can versions of new field-scale detect and track multiple pipelines Mini o-tube facility penetrometers, to allow comparative testing of reconstituted – hardware and software modules that and in situ seabed sediments, in embed these navigation, control – an experimental testing rig for support of centrifuge model testing. and guidance system in an AUV. studying general and field specific Validation of vibration-based methods Development of hardware and cyclic axial interaction behaviour ◆◆ ◆◆ to reliably monitor the condition software for controlling and between the pipe and soil behaviour of subsea pipelines (though their monitoring the performance of for general loading under drained practical implementation still depends underwater acoustic modems, while or undrained conditions on a number of issues including simultaneously recording the ambient – a mini O-tube facility for testing the ability to transmit the vibration noise and modem transmissions of soil erosion properties data and power the sensors). on a wide-bandwidth recorder. and small scale modelling of For the application of autonomous Underwater acoustic modems seabed-infrastructure-ocean ◆◆ ◆◆ underwater vehicles, the project evaluated for their capacity to transmit interaction, allowing observations developed: data along a pipeline. Long-term, of the flow conditions and 16-day trials of a five-kilometre measurement of the erosion – a new full-order particle filter communication link between two threshold of seabed sediments based navigation algorithm that seabed-mounted modems in 100m can estimate an autonomous – establishment of laboratory testing allowed detailed comparisons to be underwater vehicle’s position, apparatus to measure bed shear made between measured modem stress under tsunami-shaped waves performance and performance predicted by numerical simulators.

15 16 Subsea Pipeline Collaboration Cluster – final report Putting the Cluster’s research into practice The Collaboration Cluster’s work has revolutionised subsea pipeline technology and its findings have already been implemented in oil and gas projects off Australia and elsewhere in the world.

Meanwhile, four other long-distance Key aspects of the Cluster’s innovative models for pipe-soil interaction, leading pipelines – Gorgon, Wheatstone, Ichthys contributions to pipeline technology to reduced design uncertainty. New and Browse – are at an advanced stage include experimental techniques were developed of design, and many shorter pipelines are at UWA during the Cluster project, and being designed. These new pipelines are Industry Impact through these have resulted in more realistic technically very challenging: some will Geotechnical Centrifuge Testing simulations of pipeline behaviour. Using extend into deeper waters, well beyond these techniques, centrifuge testing the shelf break, and some – notably Two critical components of pipeline has been performed over the past four those to the Ichthys and Browse fields design are the assessment of on-bottom years, using natural soil samples gathered – will be located north of Broome, in stability under severe hydrodynamic from offshore and providing results different oceanographic and geotechnical loading – from storms or – and that have had direct impact the design conditions compared to the existing the overall response of the pipeline of offshore field pipelines. The specific experience in the Carnarvon basin. to internal and pressure. projects, operators and pipe details are Under both conditions, the pipe may be provided in the table on following page. The new challenges of new regions, permitted to move significant distances greater pipeline lengths, deeper water and back and forth across the seabed, but new geohazards, have all been tackled these movements must not be excessive within the Cluster, and the research and the pipe must not be over-strained. techniques and outcomes spearheaded by the Cluster have already been applied to A critical input to assessment of pipeline the design of Australia’s new pipelines. stability under these movements is the interaction forces between the pipe and These same technologies have also been the seabed. Centrifuge model testing, applied to projects elsewhere in the using offshore soil samples and accurate world, such as for BP’s PSVM field off simulation of the pipeline and Industry collaborator Paul Brunning of Angola, West Nile Delta offshore Egypt movements, provides observations Acergy presenting at the 2009 CSIRO and Shah Deniz in the Caspian Sea. This is that can be used to refine and validate Flagship Cluster on Pipelines workshop recognising Australia’s technical leadership in pipeline engineering and the pivotal role this Cluster has played in developing testing facilities and design practises. Existing pipeline Ichthys The Cluster’s research programs resulted Proposed pipeline in several industry advances such as:

◆◆improved site characterisation Browse through new technologies

◆◆specialised geotechnical Gorgon centrifuge testing Wheatstone ◆◆advanced numerical modelling ◆◆cyclone simulation experiments in the newly established O-Tube facility. Also, through a joint industry project involving six offshore operators (BHP Billiton Petroleum, BP, Chevron, Petrobras, Shell and Woodside), new approaches for geohazard assessment have been derived and applied in projects, including the A$43billion Gorgon project in north-west Western Australia that involves designing a pipeline to travel from 1350m water depth at the Greater Gorgon gas fields to the LNG plant on Barrow Island, near Karratha.

17 operator project year pipeline length main testing focus These centrifuge studies used new modelling technology that permits Woodside Pluto 2007 200km Lateral buckling arbitrary patterns of load and BP PSVM 2008 170km Lateral buckling displacement to be imposed on a model Chevron Gorgon 2008 65km & 150km As-laid embedment pipeline. This allowed the effects of Chevron Gorgon 2009 150km Storm stability dynamic laying, thermal start-up and shutdown cycles and hydrodynamic Chevron Gorgon 2009 150km Free span stability storm loading to be simulated. In some Chevron Wheatstone 2010 225km Buckling, storm stability cases, stochastic storm simulations to BP B31SE 2010 50km Lateral buckling assess the pipe-soil response during 1000-year and 10000-year return Inpex Ichthys (infield) 2010 50km Lateral buckling period design events were devised. The Woodside Browse 2011 400km Buckling, storm stability underlying technology is described later Inpex Ichthys (export) 2011 850km Lateral buckling in this report (also refer to centrifuge BP West Nile Delta 2011 100km Lateral buckling modelling technology section). BP Shah Deniz 2011 25km Lateral buckling Industry impact through Summary of centrifuge tests conducted for industry during the Cluster numerical modelling Numerical pipe-soil models were incorporated into the industry stability analysis package ABAQUS/SimStab for use in the Gorgon Upstream Joint Venture (GUJV) project. Cluster researchers collaborated with GUJV engineers in initially running the plasticity UWAPIPE models under Gorgon storm conditions, before incorporating the models into the SimStab software for GUJV engineers to use. The new soil models are now being used in the stability analysis of the Gorgon pipeline on the North West Shelf of Australia.

New methods to predict submarine slide- pipelineinteraction Research into the interaction between submarine slides and pipelines formed a major theme within the cluster, and also a joint industry project administered by the Minerals and Energy Research Institute of Western Australia (MERIWA Project M395) and sponsored by the six energy majors BHP Billiton Petroleum, BP, Chevron, Berms of soil along pipe in a industry test Petrobras, Shell and Woodside. Annual workshops between the sponsoring

18 Subsea Pipeline Collaboration Cluster – final report companies and researchers were using two levels of sophistication – a Velocity (m/s) 30 1.45 1.35 held in Perth and in Houston, USA. new, and more refined, implementation 1.25 1.15 of the industry-standard depth-averaged 1.05 0.95 t=0.1s This project aimed to develop new m) 20 0.85 approach, and a continuum-based large 0.75 techniques to characterise and z( 0.65 deformation finite element method. 0.55 model the geotechnical aspects 10 0.45 of submarine slide behaviour. The The techniques emerging from this project encompassed both physical research into the assessment of 0 Velocity (m/s) 3.6 modelling and numerical modelling. pipeline-slide loading have been 30 3.3 3 A program of novel centrifuge model applied to the Greater Gorgon 2.7 2.4 tests generated a library of well- development, offshore Australia. 2.1 t=3.3s m) 20 1.8 1.5 characterised submarine slides, as well z( 1.2 0.9 A further significant part of the 0.6 as a database of slide-pipe interaction 10 0.3 project was the development of a new 0 force measurements. These results were geotechnically-based framework to used to validate numerical run-out 0 characterise the strength of soft seabed Velocity (m/s) computations that were performed 30 0.12 deposits, based on extensive laboratory 0.11 0.1 0.09 measurements using different soil 0.08 0.07 t=15 s m) 20 0.06 types. This framework spans the solid- 0.05 z( 0.04 fluid boundary that is crossed within 0.03 10 0.02 the slide material as it evolves into a 0.01 debris flow and, ultimately, a 0 current. In addition, extensive analytical Velocity (m/s) 0.12 studies were performed to support 30 0.11 0.1 the development of new models for 0.09 0.08 0.07 t=69 s the interaction forces between slides m) 20 0.06 0.05 z( 0.04 and pipelines, and these were distilled 0.03 10 0.02 into simple design recommendations. 0.01

0 110120 130 140 150160 170180 190 x(m) Velocity distributions on deformed softening material Developing slide experiments at the UWA drum centrifuge

Slide run-out from centrifuge test with compression ridges highlighted

19 20 Subsea Pipeline Collaboration Cluster – final report Commissioning experimental equipment for ongoing pipeline testing in Australia

Major equipment development:

Penetrometers for pipeline site investigation The offshore industry has already made significant advances in site investigation techniques, incorporating full-flow penetrometers such as the T-bar and piezoball devices originally developed at UWA.

Piezoball penetrometers are now pipe and soil. New devices have been used routinely by the Australian site developed during the project to target investigation company, Benthic Geotech, this parameter, by applying torsional in its portable remotely operated drill loading to a toroidal penetrometer, (PROD). Extensive data were obtained or to an alternative hemi-spherical in 2010 for Woodside’s Browse project penetrometer. In both cases, the on the North-West Shelf. ROV- torsional interface response between mounted penetrometer capabilities the device and soil represents a close have been developed by companies analogue of the axial sliding resistance such as Perry Slingsby in the USA (the of a pipeline. Test data at model scale, T-bar penetrometers test on remoulded Rovdrill) and Geomarine in the UK. supported by numerical analysis, have sample of carbonate silt Piezoball tests carried out in the project quantified the relationships between have also given an insight into the axial friction and both the elapsed time interpretation of data in silty carbonate and velocity of shearing. Analytical sediments found offshore Australia. solutions have also been developed that capture these contributions for different For pipeline design, an important soil types, thus providing a method for parameter is the axial friction between interpreting data from the equipment.

21 UWA’s geotechnical centrifuges Both the beam (Figure a) and the drum centrifuges at the Centre for Offshore Foundation Systems have had continuous technical upgrades to face the challenges associated with the buckling of pipelines and the impact of submarine slides on pipelines.

These include: at various velocities through a soil ◆◆The establishment of optic fibre sample contained within the drum data transmission on both the beam ◆◆An improved motion control system centrifuge channel, simulating a pipe and the drum centrifuge improving enabling the modelling of pipeline engulfed within a submarine slide. By the transfer rate, increasing the dynamic installation with complex using a soil sample which was initially quality of the experimental data horizontal and vertical motion unconsolidated, the model pipe and enabling high definition videos interaction and the modelling of tests were performed after different to taken during experiments. pipeline buckling (Figure b) up to 600 degrees of consolidation leading to cycles. This is a major improvement varying sample properties (density compared to the previous modelling ρ and undrained shear strength su). capability (limited to about 100 Pipe translation tests were performed cycles), which revealed specific using different model pipes with features of pipe soil interaction varying length to diameter ratios related to the development of in order to determine the optimum berms and pipe embedment pipe geometry that would minimise over a large number of cycles. potential end effects. Once the test ◆◆The establishment of a new driving technique was established the main system for the tool table of the drum program of testing was undertaken. centrifuge and a new experimental This involved a total of 37 model pipe pipe apparatus. This upgrade was translation tests spanning a wide triggered by the necessity to allow a range of velocities and soil strengths. buried model pipeline to be translated Christophe Gaudin and Yinghui Tian with the beam centrifuge

Horizontal displacement direction

Model pipeline during horizontal buckling Buried model pipeline translated through clay of various strengths

22 Subsea Pipeline Collaboration Cluster – final report O-tube A new O-tube facility allows storm conditions to be simulated within a large recirculating flume.

The mini O-tube was formulated as part the Collaboration Cluster and highlighted the feasibility of the experimental testing approach. A larger O-tube was then subsequently funded by UWA, the Australian Research Council, and Woodside and Chevron, via the STABLEPIPE Joint Industry Project. The facility allows a full ocean-pipeline- seabed interaction to be simulated at large scale. Cyclonic wave and current conditions can be created in the 1.5 m high test section, flowing over a 15 m long mobile sediment bed. The long-term aim is to allow seabed mobility, manifested through scour and liquefaction, to be incorporated in simulations of pipeline on-bottom stability – which currently neglect these potentially important processes. This project is led by Liang Cheng, with Hongwei An (UWA) and David White and Mark Randolph. Support for this initiative was provided by Andrew Palmer (National University of Singapore), as well as Woodside (Nino

Fogliani and Roland Fricke) and the local Scott Draper with the miniature O-tube consultancies JP Kenny (Terry Griffiths) and Atteris (Eric Jas). Conference papers describing the O-tube activity were presented at the Offshore Pipeline Technology Conference (in Amsterdam) and the ISOPE Conference (Shanghai).

The large o-tube, assembled at the UWA Shenton Park field station

23 Propagation buckling A subsea pipeline can experience a number of structural instabilities, such as lateral (snaking) buckling, upheaval buckling, span formation and propagation buckling.

Among these, propagation buckling increase in material and installation cost for propagation buckling was is the most critical one, particularly in of the pipeline, since design is therefore proposed and a finite element model deep water, and can quickly damage governed by propagation pressure. was established and verified with many kilometres of pipeline. the experimental results. Based on A hyperbaric chamber was constructed for these findings, a new pipe topology is A local buckle, ovalisation, dent or the simulation of propagation buckling proposed. Finite element analysis of the in the pipe wall can quickly in ultra-deep subsea pipelines. The new pipe, a faceted cylinder, shows a transform the pipe cross-section into pressurised testing vessel is 4 m long with substantial increase in buckling capacity a dumb-bell (or dog bone) shape that an internal diameter of 173mm and is rated for the same diameter/thickness ratio. travels along the pipeline as long as the for 20 MPa (2000 m water depth). A testing external pressure is high enough to sustain protocol was successfully established and The coupling of upheaval and lateral propagation. The lowest pressure that numerous tests were conducted on 3m buckling with propagation buckling maintains propagation is the propagation long steel and aluminium pipes. A simple is being investigated together with pressure that is only a small fraction testing procedure using a ring segment exploring the possible modification of the elastic collapse pressure of the of the pipeline was also established as of the hyperbaric chamber to simulate intact pipe. This results in a substantial a preliminary test. A modified analytical this form of coupled buckling.

Axial pipeline walking A testing system to investigate axial pipeline walking under drained and undrained conditions has been established at Monash University, Australia.

A sophisticated 2D electrical actuator with displacement controlled cycles can be Second, the test pipe is allowed to settle a precision of 0.01 mm/sec (to account performed at different rates depicting on the model seabed. Third, the test pipe for the slow axial walking process) was both undrained and drained conditions. is subjected to cyclic axial displacements devised to simulate the pipe motion The system is suitable for element testing using the horizontal actuator. On the on a laboratory-made clay seabed. A of typical prototype pipe diameters. basis of instrumentation provided, the horizontal linear motor capable of driving axial on the test pipe section, pore Dummy sections at the ends of the test the shaft with a drive force between water pressure at pre-determined pipe section are provided to reduce 300 to 500 N for a stroke length of 200 locations and vertical settlement of boundary effects in simulation of a long mm is provided. The vertical motion is pipe are measured. The test results pipe. The following steps are used in a controlled by a motor providing 200 produce the shear stress-displacement typical experiment. First, a model seabed is to 300 N drive force to an expected characteristics of the pipe-soil interface prepared and characterised using a T bar. stroke length of 200 mm. Both load and applicable to axial walking problems.

The Monash Advance Pipe Testing System (MAPS)

24 Subsea Pipeline Collaboration Cluster – final report Tsunami testing facility Novel bed shear stress measurements were performed in the UQ tsunami wave flume, which is 25 m long and 0.8 m wide.

The shear cell consists of a 100 mm long, a physical model test for a solitary wave Numerical modelling of tsunami sources 250 mm wide and 1.21 mm thick smooth is shown below. Numerical modelling along the Sunda Arc has shown the plate supported on thin tubular sway of the laboratory experiments has been locations of principal on the legs, with displacement measured by an performed and used to calibrate and test WA continental slope and shelf, together eddy-current sensor which resolves plate a tsunami model for prediction of seabed with hotspots of high bed shear stress, movement to 0.001 mm. The wave flume shear stresses in the field. both of which can be utilised in pipeline was equipped with a computer-controlled routing studies. piston wave-maker having a maximum stroke length of 1.2 m and capable of generating most types of waves including solitary waves and bores. The experimental model was set up to represent a continental slope and shelf region, with measurements made on the slope and horizontal sections. Measurements were made over both a smooth bed and a rough bed. Both non-breaking and breaking (bores) were investigated. Microsonic® ultrasonic wave gauges were used to measure the wave heights and a SONTEK® 2D Acoustic Doppler Velocimeter was used to measure the flow velocities. A photo of

A solitary wave at the shelf edge in the UQ experiments

25 Acoustic modems The capability to perform at-sea evaluations of underwater acoustic communication links has been enhanced by the development of equipment to allow the unattended, autonomous operation and monitoring of such links for extended periods of time.

Battery operated, and mounted in pressure proof housings, the equipment controls the operation of the modems and monitors their performance while simultaneously monitoring ambient noise and the water column temperature profile. It has been successfully used for several experiments, including a 16-day unattended trial in 100 m of water off the Western Australian coast. It can be readily modified to suit other types of underwater acoustic modems. The development of this hardware has been complemented by the development of a modem performance simulator that can be used to investigate the effects of different environmental factors on communication link performance.

Experimental setup for the long-term trial showing all equipment used in the deployment. Two sets of equipment were deployed which periodically communicated with one another while recording information including ambient noise levels and a temperature profile for the bottom 50 m of the water column.

26 Subsea Pipeline Collaboration Cluster – final report Autonomous underwater vehicles The algorithms developed to control, navigate and guide AUVs have all been tested numerically using realistic purpose-built simulators.

The developed algorithms must, position while deploying instruments build 3D relief maps of the seabed and however, be physically validated into the seabed, and turn tightly while track pipelines and obstacles. It also has using a real vehicle equipped with the manoeuvring close to obstacles. The doppler velocity sensors and IMUs for necessary sensors and actuators. AUV is equipped with forward looking navigation, as well other instruments and plus side scan sonar to for acoustic and radio communications. The majority of AUVs currently available from vendors are either closed architecture which would prevent alternative algorithms from being used on the vehicle, or are too expensive, or too small to be useful. The decision was therefore taken to custom build a modular vehicle that can satisfactorily validate the developed algorithms and with enough flexibility to meet the range of survey/intervention requirements posed by the offshore oil and gas. This vehicle is currently being built in collaboration with the Australian Maritime College. The vehicle is equipped with four lateral thrusters as well as one propulsion thruster permitting it to hover and hold CAD image of an AUV

27 Postgraduate Publications and dissemination profile Members of the Cluster have published 80 journal and 82 conference manuscripts from their research. A further Matt Hodder five technical reports were written specifically for the cluster and three book chapters were published. Geotechnical analysis of offshore pipelines and steel 1. Alam, M. S. and L. Cheng (2009), A 2-D 12. Baldock, T. E. and D. Peiris (2011). model to predict time development Overtopping and run-up hazards induced catenary risers of scour below pipelines with by solitary waves and bores. Tsunami spoiler, 12th International Conference Threat - Research and Technology, In-Tech. Matt Hodder’s thesis investigated on Enhancement and Promotion of 13. Baldock, T. E. and J. K. Seelam (2009), the interaction of cylindrical Computational Methods in Engineering Numerical and physical modelling objects with soil, and its application and Science, Hong Kong – Macau. of tsunami run-up and impact on to the analysis and design of 2. Alam, M. S. and L. Cheng (2009), subsea pipelines, 1st Annual Society offshore pipelines and risers. Blockage ratio and mesh dependency for Underwater Technology Subsea study for Lattice Boltzmann flow around Technical Conference (SUT), Perth, CD. The behaviour observed during cylinder, 12th International Conference 14. Bao, C. X., X.Q Zhu, H. Hao and experiments performed to assess the on Enhancement and Promotion of Z.X. Li (2008), Operational modal effect of various loading conditions Computational Methods in Engineering analysis using correlation-based on pipe-soil interaction response was and Science Hong Kong – Macau. ARMA models, 10th International used to develop analytical models 3. Alam, M. S. and L. Cheng (2009), Modelling Symposium on Structural Engineering appropriate to use in an integrated of flow around a square cylinder of different for Young Experts, CD:1459-1464. soil-structure interaction assessment of roughness using a lattice Boltzmann 15. Bao, C. X., X.Q Zhu, H. Hao and Z.X. model, 28th International Conference on the pipe-soil system. The apparatus and Li (2008), Variable modal parameter Ocean, Offshore and Arctic Engineering, analysis methodology developed allows identification using an improved Honolulu, Hawaii, OMAE2009-80155. comparisons of behaviour observed HHT algorithm, 10th International during experiments performed using 4. Alam, M. S. and L. Cheng (2010), A Symposium on Structural Engineering a short ‘element’ of pipeline assuming parallel three-dimensional scour model for Young Experts, CD:1465-1470. to predict flow and scour below a two-dimensional plane-strain conditions 16. Bao, C. X., H. Hao, Z.X. Li and X.Q. submarine pipeline, Central European Zhu (2009), Time-varying system and the validation of pipe-soil interaction Journal of Physics, 8(4): 604-619. models developed from element tests. identification using an improved 5. Albermani, F., H. Khalilpasha and H. HHT algorithm, Computers and This thesis progresses the understanding Karampour (2011), Propagation buckling Structures, 87(23-24): 1611-1623. in deep subsea pipelines, Pipelines of geotechnical aspects of offshore 17. Barnes, M. P., T. O’Donaghue, J.M. Alsina International Digest, January 2011: 7-8. pipeline and riser behaviour. It also and T.E. Baldock (2009), Direct bed shear advances the predictive capabilities 6. Albermani, F., H. Khalilpasha and stress measurements in bore-driven of pipe-soil interaction models, H. Karampour (2011), Propagation swash, Coastal Engineering, 56: 853-867. buckling in deep sub-sea pipelines, enabling more accurate response 18. Barnes, M. P. and T. E. Baldock (2010), A Engineering Structures: 33(9): 3547-2553. assessment and efficient design. Lagrangian model for boundary layer 7. An, H., L. Cheng nd M. Zhao (2010). growth and bed shear stress in the swash Direct numerical simulation of 3D steay zone, Coastal Engineering,(57): 385-396. streaming induced by Honji Instability. 19. Boukpeti, N., D.J. White and M.F. Randolph 17th Australasian Fluid Mechanics (2009), Characterization of the solid-liquid Conference, Auckland, New Zealand. transition of fine-grained sediments, 8. An, H., L. Cheng and M. Zhao (2010), 28th International Conference on Offshore Steady streaming around a circular Mechanics and Arctic Engineering, cylinder in an oscillatory flow, Ocean Honolulu, Hawaii, OMAE2009-79738. Engineering, 36(14): 1089-1097. 20. Boukpeti, N., D. White and M.F. 9. An, H., Cheng, L., Zhao, M., (2010), Steady Randolph (2012) Analytical modelling streaming around a circular cylinder near of the steady flow of a submarine a plane boundary due to oscillatory flow. , slide and consequent loading on a Journal of Hydraulic Engineering: (accepted). pipeline, Géotechnique, 62(2) 137-146. 10. An, H., Cheng, L., Zhao, M. (2011), Direct 21. Boukpeti, N., D.J. White, M.F. Randolph numerical simulation of oscillatory and H.E. Low (2012), The strength of flow around a circular cylinder at low fine-grained soils at the solid-fluid Keulegan-Carpenter number, Journal transition, Geotechnique: in press, posted of Fluid Mechanics, 666: 77-103. ahead of print, 10.1680/geot.9.P.069. 11. Baldock, T. E., D. Cox, T. Maddux, J. 22. Boylan, N., C. Gaudin, D.J. White, M.F. Killian and L. Fayler (2009), Kinematics Randolph and Schneider, J.A. (2009), of breaking tsunami waves: a data set Geotechnical centrifuge modelling from large scale laboratory experiments, techniques for submarine slides, 28th Coastal Engineering, 56: 506-516. International Conference on Offshore Mechanics and Arctic Engineering, Honolulu, Hawaii, OMAE2009-79059.

28 Subsea Pipeline Collaboration Cluster – final report 23. Boylan, N., C. Gaudin, D.J. White and M.F. 36. Guard, P. A., T.E. Baldock and P. Nielsen Randolph (2010), Modelling of submarine (2009), Bed shear stress in unsteady Postgraduate slides in the geotechnical centrifuge, flow, Coasts and Ports, Wellington, NZ. 7th International Conference on Physical 37. Hodder, M., M.J. Cassidy and D. Modelling in Geotechnics (ICPMG 2010), Barrett (2008), Undrained response Zurich, Switzerland CD:1095-1100. of pipelines subjected to combined profile 24. Boylan, N. and M. F. Randolph (2010), vertical and lateral loading, 2nd Enhancement of the ball penetrometer International Conference on Foundations test with pore pressure measurements, (ICOF), Bracknell, UK, CD:897-908. Grant Pusey 2nd International Symposium on Frontiers 38. Hodder, M. S., White, D.J., Cassidy, M.J. in Offshore Geotechnics (ISFOG 2010), Characterisation of long- (2012) An effective stress framework for Perth, Australia, CD:259-264. the variation in penetration resistance range horizontal performance 25. Boylan, N. P., C. Gaudin, D.J. White due to episodes of remoulding and of underwater acoustic and M.F. Randolph (2012), Centrifuge reconsolidation, Géotechnique, 63(1): 30-43. modelling of submarine slides, Ocean communication 39. Hodder, M. S., D.J. White and M.J. Engineering: under review April 2011. Cassidy (2009), Effect of remoulding Grant’s study sought to characterise the 26. Boylan, N. P. and D. J. White (2010). and reconsolidation on the touchdown performance of horizontal underwater Geotechnical frontiers in offshore stiffness of a steel catenary riser: acoustic data communication in engineering - invited keynote lecture. Observations from centrifuge modelling, various scenarios with particular International Symposium on Recent 41st Offshore Technology Conference, Advances and Technologies in Coastal Houston, Texas, OTC-19871. application to subsea monitoring Development, Tokyo, Japan, CD: 18 pages. and control systems. This involved 40. Hodder, M. S. and M. J. Cassidy (2010), A conducting field trials to simultaneously 27. Cassidy, M.J. and Y. Tian (2007), plasticity model for predicting the vertical Technical note on pipesoil data and lateral behaviour of pipelines in clay measure environmental parameters interaction model testing, GEO:08451. soils, Geotechnique, 60(4): 247–263. and communication performance. 28. Cassidy, M.J. and Y. Tian (2008), 41. Hodder, M. S., D. J. White, et al. (2010), An underwater acoustic communication Technical note on implementation of Analysis of strength degradation during simulator was also developed UWAPIPE into ABAQUS, GEO:07421. episodes of cyclic loading, illustrated by and the results compared to the the T-bar penetration test, International 29. Chatterjee, S., D.J. White, D. Wang experiments. This thesis investigates Journal of Geomechanics, 10(3): 117-123. and M.F. Randolph (2010), Large the environmental dependency of deformation finite element analysis of 42. Jaeger, R. A., J.T. DeJong, R.W. Boulanger, communication performance and the vertical penetration of pipelines into the H.E Low and Randolph, M.F. (2010), feasibility of using the technology seabed, 2nd International Conference in Variable penetration rate CPT in an Frontiers in Offshore Geotechnics (ISFOG intermediate soil, 2nd International in place of cabled telemetry. 2010), Perth, Australia, n/a:785-790. Symposium on Cone Penetration Testing, CPT10, Huntington Beach, California. 30. Cheng, L., K. Yeow, Z. Zang and B. Teng (2009), Three-dimensional scour 43. Khalilpasha, H. (2010). Buckling propagation below pipelines in steady currents, of subsea pipelines. EAIT Postragraduate Coastal Engineering, 56(5-6): 577-590. Student Conference, Queensland, Australia. 31. Davies, M. C. R., E.T. Bowman and D.J. 44. Khalilpasha, H. (2011). Nonlinear White (2010), Physical modelling of numerical investigation of buckle natural hazards - a keynote lecture, 7th propagation in subsea pipelines. The 1st International Conference on Physical International Postgraduate Conference on Modelling in Geotechnics (ICPMG 2010) Engineering, Designing and Developing Zurich, Switzerland, CD:3-22. the Built Environment for Sustainable Wellbeing, Brisbane, Australia. 32. DeJong, J., N. Yafrate, D. DeGroot, H.E. Low and M.F. Randolph (2010), Recommended 45. Khalilpasha, H. and F. Albermani (2011). practice for full flow penetrometer On the propagation buckling and effects testing and analysis, ASTM Geotechnical in ultra-long deep subsea pipelines. Testing Journal, 33(2): 13 pages. 30th International Conference on Ocean, Offshore and Arctic Engineering (OMAE 33. DeJong, J. and M. F. Randolph (2012), 2011), Rotterdam, The Netherlands. Influence of partial consolidation during cone penetration on estimated 46. Kodikara, J. K. (2008). Study of the axial soil behaviour type and pore pressure response and its coupling of the general dissipation measurements, Journal pipe-soil interaction of seabed pipelines. of Geotechnical & Geoenvironmental 47. Kokegei, M., F. He and K. Sammut (2008), Engineering, 138(7): 777-788. Fully-coupled 6 degress-of-freedom control 34. DeJong, J. T., N.J. Yafrate and M.F. of autonomous underwater vehicles, Randolph (2008), Use of pore pressure IEEE Oceans 2008, submitted July 2008. measurements in a ball full-flow 48. Kokegei, M., F. He and K. Sammut (2009), penetrometer, 3rd International Conference Nonlinear fully-coupled control of AUVs, on Site Characterization, Taiwan, 1269-1275. 1st Annual Society for Underwater Society 35. Gaudin, C., D.J. White, N. Boylan, J. Subsea Technical Conference (SUT), Perth. Breen, T.A. Brown, S. De Catania and P. 49. Kokegei, M., He, F. and Sammut, K. Hortin (2009), A wireless high speed data (2011). Fully coupled 6 DoF control of an acquistion for geotechnical centrifuge over-actuated autonomous underwater model testing, Measurement Science vehicle. Underwater Vehicles, InTech. and Technology, 20(9): 11 pages.

29 50. Lammas, A., K. Sammut and He, 63. Liu, H.B, and X.L. Zhao (2012), Fatigue Postgraduate F. (2008), Improving navigational Behaviour of Welded Steel Connections accuracy for AUVs using the MAPR under Combined Actions, Advances particle filter, IEEE Oceans 2008. in Structural Engineering – An International Journal, 15(10): 1817-1828. 51. Lammas, A., K. Sammut and He, F. profile (2009). 6-DoF navigation systems for 64. Liu, H.B and X.L. Zhao (2013), Prediction autonomous underwater vehicles. Mobile of fatigue life for CFRP strengthened Robots Navigation, In-Tech Books. steel connections under combined Bassem Youssef loads, International Journal of Structural 52. Lammas, A., K. Sammut and He, F. (2009), Stability and Dynamics, 12(6): DOI: MAPR particle filter for AUV sensor fusion, The Integrated Stability Analysis 10.1142/S0219455412500599 1st Annual Society for Underwater Society of Offshore Pipelines Subsea Technical Conference (SUT), Perth. 65. Low, H. E., M.F. Randolph, C.J. Rutherford, B.B. Bernard and J.M. The dissertation is concerned with the 53. Lammas, A. S., K. and He, F. (2012), Brooks (2008), Characterization of Measurement-assisted partial resampling stability analysis of offshore pipelines near seabed surface sediment, Offshore particle filter for full-order state-estimation under wave and current loading. An Technology Conference, OTC19149. integrated hydrodynamic-pipe-soil of an AUV’s hydrodynamic parameters, IEEE Oceanic Engineering: submitted April 2011. 66. Low, H. E., M.F. Randolph, J.T. DeJong and modeling program is developed and N.J. Yafrate (2008), Variable rate full-flow 54. LeBlanc, C. and M. F. Randolph (2008), used in investigating the pipeline penetration tests in intact and remoulded Interpretation of piezocones in silt, stability in conditions found on the soil, 3rd International Conference on Site using cavity expansion and critical state Characterization, Taiwan, 1087-1092. Australian North West Shelf and the methods, 12th International Conference Gulf of Mexico. The developed program of International Association for Computer 67. Low, H. E., T. Lunne, K.H. Andersen, is a combination of three individual Methods and Advances in Geomechanics M.A. Sjursen, M.A., X. Li and M.F. programs to perform an integrated (IACMAG), Goa, India, CD:822-829. Randolph (2010), Estimation of intact and remoulded undrained shear pipeline simulation. A hydrodynamic 55. Lee, J. and M. F. Randolph (2011), strengths from penetration tests in soft modelling program that generates Penetrometer based assessment of clays, Geotechnique, 60(11): 843-859. 3D ocean surface, estimates the wave spudcan penetration resistance, Journal kinematics at the pipeline level and of Geotechnical & Geoenvironmental 68. Low, H. E., M. F. Randolph, T. Lunne, K.H. Engineering: 137(6): 587-596. Andersen and M.A. Sjursen (2011) Effect calculates the hydrodynamic loads on the of soil characteristics on relative values 56. Lehane, B., C. O’Loughlin, C. Gaudin pipeline. A pipe-soil modelling program of piezocone, T-bar and ball penetration and M.F. Randolph (2009), Rate that simulates the complicated pipe-soil resistance, Geotechnique, 61 (8): 651-664. interaction behaviour under complex effects on penetrometer resistance in kaolin, Geotechnique, 59(1): 41-52. 69. Low, H. E., M.M. Landon, M. F. hydrodynamic loading. The pipeline Randolph and D. DeGroot, (2011) 57. Li, Y. H., K.Q. Fan, X.Q. Zhu and H. Hao is modelled using the commercial Geotechnical characterisation and (2009), Operational modal identification finite element program ABAQUS. engineering properties of Burswood of offshore structures using blind clay, Geotechnique, 61 (7): 575-591. Advanced statistical methods are source separation, 1st Annual Society for utilized in the thesis to investigate Underwater Technology Subsea Technical 70. Low, H. E. and M. F. Randolph (2010), Conference (SUT), Perth, CD: SUT09-LiYH. Strength measurement for near the reliability of the pipeline stability seabed surface soft soil, Journal of 58. Liu, H. B., X.L. Zhao and Z.G. Xiao (2010), and the sensitivity of the design Geotechnical and Geoenvironmental Fatigue testing of subsea pipeline input parameter. Pipeline centrifuge Engineering, 136(11): 1565-1573. steel connections under combined modeling is conducted under complex actions, The 21st Australasian Conference 71. Lunne, T., K.H. Andersen, H..E. Low, hydrodynamic loading, with the results on the Mechanics of Structures and M. F. Randolph and M.A. Sjursen, used to validate the integrated program. Materials, Melbourne, 649-655. (2011) Guidelines for offshore in situ The study provides engineers with a testing and interpretation, Canadian 59. Liu, H. B. and X. L. Zhao (2011). Predictions Geotechnical Journal, 48(4): 543-556. 3D pipeline modeling program and of fatigue life of steel connections methodologies to achieve reliable under combined actions using boundary 72. Mahmoodzadeh, H., N, Boylan, M.F. and economic pipeline designs. element method. 21st International Randolph and M.J. Cassidy (2011). The Offshore and Polar Engineering effect of partial drainage on measurements Bassem received an Innovation Award Conference, Maui, Hawaii, 4: 276-281. by a piezoball penetrometer. 30th Commendation from the Australian Gas International Conference on Ocean Offshore 60. Liu, H. B. and X. L. Zhao (2012). Fatigue Technology Conference (Perth-2012) and Arctic Engineering (OMAE2011), behaviours of subsea pipeline steel Rotterdam, The Netherlands. for the development of the integrated connections under combined actions. pipeline simulation program. 7th International Conference on Advances 73. Merifield, R. S., D.J. White and M.F. in Steel Structures, Nanjing, China. Randolph (2008), The effect of pipe- soil interface conditions on undrained 61. Liu, H. B. and X. L. Zhao (2012). breakout resistance of partially- Fracture mechanics analysis of steel embedded pipelines, 12th International connections under combined actions. Conference on Advances in Computer 7th International Conference on Advances Methods and Analysis in Geomechanics in Steel Structures, Nanjing, China. (IACMAG), Goa, India, CD:4249-4256. 62. Liu, H. B. and X. L. Zhao (2012). Repair 74. Merifield, R. S., D.J. White and M.F. efficiency of CFRP reinforced steel Randolph (2009), The effect of surface connections under combined actions. heave on the response of partially- 6th International Conference on Fibre embedded pipelines on clay, Journal Reinforced Polymer Composites in of Geotechnical and Geoenvironmental Civil Engineering, Rome, Italy. Engineering, 135(6): 819-826. 75. Osman, A. S. and M. F. Randolph and Arctic Engineering (OMAE 2009), 100. Seelam, J. K. and T. E. Baldock (2011). (2010), Response of a solid infinite Honolulu, Hawaii, OMAE2009-79259. Tsunami induced bed shear strewsses cylinder embedded in a poroelastic on Northwest Coast of Australia. 87. Randolph, M. F. and D. J. White (2008), medium and subjected to a lateral International Conference of Asia Oceania Offshore foundation design – a load, International Journal of Solids Geosciences Society (AOGS2011), Taiwan. moving target. Keynote paper, 2nd and Structures, 47(18-19): 2414-2424. International Conference on Foundations 101. Seelam, J. K. and T. E. Baldock (2011). 76. Peng, X. L. and H. Hao (2008), Damage (ICOF), Bracknell, UK, 27-59. Tsunami induced shear stresses along detection of underwater pipeline using submarine canyons off south-east coast of 88. Randolph, M. F. and D. J. White (2008), vibration-based method, 3rd World India. 6th International Conference on Asia Pipeline embedment in deep water Congress on Engineering Asset Management and Pacific Coasts (APAC2011), Hong Kong. processes and quantitative assessment, and Intelligent Maintenance System. Offshore Technology Conference, OTC19128. 102. Seelam, J. K. and T. E. Baldock (2012). 77. Pusey, G., A. Duncan and A. Smerdon Solitary wave friction factors from 89. Randolph M.F. and D.J. White (2012), (2009), Analysis of acoustic modem direct shear measurements on a sloping Interaction forces between pipelines performance for long range bed. 8th International Conference and submarine slides - a geotechnical horizontal data transmission, OCEANS on Coastal and Port Engineering in viewpoint. Ocean Engineering, 48, 32-37. 09 IEEE Bremen, Germany. Developing Countries, Madras, India. 90. Rognon, P. G., I. Einav and C. Gay 78. Pusey, G. (2011). Characterisation of 103. Seelam, J. K. and T. E. Baldock (2011), (2010), Internal relaxation time in long-range horizontal performance of Comparison of bed shear under immersed particulate materials, underwater acoustic communication, non-breaking and breaking solitary Physical Review E, 81: 061304. Curtin University, PhD Thesis. waves, International Journal of Ocean 91. Rognon, P. G., I. Einav, J. Bonivin and and Climate Systems: 2(4): 259-278. 79. Pusey, G. and A. Duncan (2008), T. Millar (2010),A scaling law for heat Characterisation of underwater 104. Senthilkumar, M., P. Rajeev, P. and J. conductivity in sheared granular material, acoustic modem performance for Kodikara (2010). Offshore pipe clay- Europhysics Letters, 89, pp 58006. real-time horizontal data transmission, seabed interaction in axial direction. Australian Acoustical Society Annual 92. Rognon, P. G. and C. Gay (2008), Soft Cluster workshop: abstract. Conference 2008, Geelong. dynamics simulation 1: normal approach 105. Senthilkumar, M., J. Kodikara and P. of two deformable particles in a viscous 80. Pusey, G. and A. Duncan (2009), Rajeev (2011). Numerical modelling of fluid and optimal-approach strategy, The Development of a simplistic underwater undrained vertical load-deformation European Physics Journal, 27: 253-260. acoustic channel simulator for analysis and behaviour of seabed pipelines. prediction of horizontal data telemetry, 93. Rognon, P. G. and C. Gay (2009), Soft 13th International Confernce of the Australian Acoustical Society National dynamics simulation 2: elastic spheres International Association for Computer Conference, Adelaide, abstract submitted. undergoing T1 process in a viscous fluid, Methods and Advances in Geomechanics The European Physics Journal, 30: 291-301. (IACMAG 2011), Melbourne, Australia. 81. Pusey, G. and A. Duncan (2009), An investigation of oceanographic parameters 94. Schneider, J. A., M.F. Randolph, P.W. 106. Senthilkumar, M., J. Kodikara and P. affecting acoustic modem performance for Mayne and N. Ramsey (2008), Analysis Rajeev (2011). Numerical modelling of horizontal data transmission, Underwater of factors influencing soil classification vertical load-displacement behaviour Acoustic Measurements Technologies using normalized piezocone tip resistance of offshore pipeline using coupled and Results 3rd International Conference and pore pressure parameters, Journal analysis. Pan Am CGS Geotechnical and Exhibition, Nafplion, Greece. of Geotechnical and Geoenvironmental Conference, Toronto, Canada. Engineering, 134(11): 1569-1586. 82. Pusey, G. and A. Duncan (2009), A 107. Senthilkumar, P. R., M., J. Kodikara and preliminary study of underwater acoustic 95. Schneider, J. A., M.F. Randolph, P.W. N.I. Thusynathan (2011). Laboratory communications over horizontal ranges, Mayne and N. Ramsey (2008), Influence of modelling of pipe-clay seabed interaction 1st Annual Society for Underwater Society partial consolidation during penetration in axial direction. International Subsea Technical Conference (SUT) Perth, CD. on normalised soil classification by Symposium of Offshore and Polar piezocone, 3rd International Conference on Engineering 2011, Maui, Hawaii. 83. Randolph, M. F., D. Wang, H. Zhou, Site Characterization, Taiwan, 1159-1165. M.S. Hossain and Y. Hu (2008), 108. Sleelam, J. K., Baldock, T.E. (2010), Large deformation finite element 96. Seelam, J. K., P.A. Guard and T.E. Baldock Tsunami induced currents in vicinity analysis for offshore applications, (2011), Measurements and modelling of of Palar submarine canyon off south- 12th International Conference of bed shear stress under solitary waves, east coast of India – a numerical International Association for Computer Coastal Engineering, 58: 937-947. model study, Poster presentation at Methods and Advances in Geomechanics International Conference of Asia Oceania (IACMAG), Goa, India, CD:3307-3318. 97. Seelam, J. K. and T. E. Baldock (2009), Geosciences Society (AOGS 2010), India. Direct bed shear stress measurements 84. Randolph, M. F., D. Seo and D.J. under solitary tsunami-type waves 109. Tian, Y., M.J. Cassidy and G. Gaudin, White (2010), Parametric solutions and breaking tsunami wavefronts, (2008), Pipeline integrity: centrifuge for slide impact on pipelines, Journal International Conference on Coastal modelling of pipes in sand, Geo:09475. of Geotechnical & Geoenvironmental Dynamics, Tokyo, Japan. 110. Tian, Y., M.J. Cassidy and C. Gaudin Engineering, 136(7): 940-949. 98. Seelam, J. K. and T. E. Baldock (2009), (2010), Advancing pipe-soil interaction 85. Randolph, M. F., C. Gaudin, S.M. Role of submarine canyon on tsunami models through geotechnical centrifuge Gourvenec, D.J. White, N. Boylan and amplification on south east coast testing in calcareous sands, Applied M.J. Cassidy (2011), Recent advances in of India, International Conference of Ocean Research, 32(3): 284-297. offshore geotechnics for deepwater Asia Oceania Geosciences Society, 111. Tian, Y., M.J. Cassidy and B.S. Youssef oil and gas developments, Ocean Singapore, poster presentation. (2010). Consideration for on-bottom Engineering, special issue: 38(7): 818-834. 99. Seelam, J. K. and T. E. Baldock (2010), stability of unburied pipelines using 86. Randolph, M. F. and P. Quiggin (2009), Measurements and modelling of direct force-resultant models. 20th International Non-linear hysteretic seabed model for bed shear stress under solitary waves, 9th Offshore and Polar Engineering Conference catenary pipeline contact, 28th International International Conference on Hydro-Science (ISOPE), Beijing, China, 2: 212-219. Conference on Offshore Mechanics and Engineering, Chennai, India, 421-430.

31 112. Tian, Y., M.J. Cassidy and C. Gaudin 125. Wang, D., D.J. White and M.F. Randolph 137. Xiao, Z. G. and X. L. Zhao (2007), (2011). Centrifuge tests of shallowly (2010), Large deformation finite element Frequency analyses of free spanning embedded pipeline on undrained and analysis of pipe penetration and large- subsea pipelines with finite element partially drained silt sand. GEO: 11560. amplitude lateral displacement, Canadian method, 5th International Conference on Geotechnical Journal, 47(8): 842-856. Advances in Steel Structures, 3:645-650. 113. Tian, Y., D. Wang and M.J. Cassidy (2011). Large deformation finite element 126. Wang, D., M.F. Randolph and D.J. White 138. Xiao, Z. G. and X. L. Zhao (2008), Stress analysis of offshore geotechnical (2012), A dynamic large deformation finite analyses of free spanning subsea penetration tests. 2nd International element method and element addition pipelines with finite element method, Symposium on Computational Mechanics technique, International Journal for 10th International Symposium on Structural (ComGeo11), Cavtat-Dubrovnik, Croatia. Geomechanics: under review April 2011. Engineering for Young Experts. 114. Tian, Y., M.J. Cassidy and B.S. Youssef 127. Wang, Y., X.Q. Zhu, H. Hao and 139. Xiao, Z. G. and X. L. Zhao (2010), (2011), Consideration for on-bottom K.Q. Fan (2009), Development and Prediction of Natural Frequency of Free stability of unburied pipelines using a testing of guided wave techniques Spanning Subsea Pipelines, International dynamic fluid-structure-soil simulation for pipeline integrity monitoring, Journal of Steel Structures, 10(1): 81-90. program, International Journal of Offshore 1st Annual Society for Underwater 140. Xiao, Z. G. and X. L. Zhao (2010), and Polar Engineering: 21(3): 1-8. Society Subsea Technical Conference Frequency analyses of free spanning (SUT), Perth, CD:SUT009-WangY. 115. Tian, Y. and M. J. Cassidy (2008), Explicit subsea pipelines, International Journal and Implicit integration algorithms for 128. Westgate, Z., D.J. White and M.F. Randolph of Steel Structures 10(1): 1598-2531. an elastoplastic pipe-soil interaction (2009), Video observations of dynamic 141. Yafrate, N. J., J.T. DeJong, D. DeGroot macroelement model, 27th International embedment during pipelaying, 28th and M.F. Randolph (2009), Evaluation Conference on Offshore Mechanics and International Conference on Offshore of remolded shear strength and Arctic Engineering, OMAE2008-57237. Mechanics and Arctic Engineering (OMAE sensitivity of soft clay using full 2009), Honolulu, Hawaii, OMAE2009-79814. 116. Tian, Y. and M. J. Cassidy (2008), Modelling flow penetrometers, Journal of of pipe-soil interaction and its application 129. Westgate, Z., M.F. Randolph, M.F, D.J. Geotechnical and Geoenvironmental in numerical simulation, International White and S. Li (2010), The influence Engineering, 135(9): 1179-1189. Journal of Geomechanics, 8(4): 213-229. of seastate on as laid pipeline 142. Yan, Y., White, D.J. and Randolph, M.F. embedment: a case study, Applied 117. Tian, Y. and M. J. Cassidy (2008), A practical (2010), Investigation into the toroid Ocean Research, 32(4): 321-331. approach to numerical modelling of penetrometer on non-homogeneous clay, pipe-soil interaction, 18th International 130. Westgate, Z., D.J. White and M.F. 2nd International Symposium on Frontiers Offshore and Polar Engineering Conference Randolph (2010), Pipeline laying and in Offshore Geotechnics (ISFOG2010), (ISOPE), Vancouver, Canada, 2:533-538. embedment in soft fine-grained soils: field Perth, Western Australia, CD:321-326. observations and numerical simulations., 118. Tian, Y. and M. J. Cassidy (2009), Pipe- 143. Yan, Y., D.J. White and M.F. Randolph Offshore Technology Conference, Houston, soil interaction analysis with a 3D (2011), Penetration resistance and stiffness OTC2010:Paper number 20407. macroelement model, 19th International factors in uniform clay for hemispherical Offshore and Polar Engineering Conference 131. Westgate, Z. J., M.F. Randolph and D.J. and toroidal penetrometers, International (ISOPE), Osaka, Japan, 461-468. White (2010), Theoretical, numerical and Journal for Geomechanics: 11(4): 263-275. field studies of offshore pipeline sleeper 119. Tian, Y. and M. J. Cassidy (2010), The 144. J.T. Yi, S.H. Goh, F.H. Lee and M.F. crossings, 2nd International Symposium challenge of numerically implementing Randolph,(2012), A numerical study of on Frontiers in Offshore Geotechnics, numerous force-resultant models cone penetration in fine-grained soils Perth, Australia, n/a:845-850. in the stability analysis of long on- allowing for consolidation effects, bottom pipelines, Computers and 132. White, D. J., C. Gaudin, N. Boylan Géotechnique, 62(8): 707 –719. Geotechnics, 37(1-2): 216-232. and H. Zhou (2010), Interpretation of 145. Youssef, B. S., M.J. Cassidy and Y. Tian T-bar penetrometer tests at shallow 120. Tian, Y. and M. J. Cassidy (2010), A pipe-soil (2010), Balanced three-dimensional embedment and in very soft soils, Canadian interaction model incorporating large modelling of the fluid-structure-soil Geotechnical Journal, 47(2): 218-229. lateral displacements in calcareous sand, interaction of an untrenched pipeline, 20th Journal of Geotechnical & Geoenvironmental 133. White, D. J. and D. N. Cathie (2010). International Offshore and Polar Engineering Engineering, 137(3): 279-287. Geotechnics for subsea pipelines – a Conference (ISOPE), Beijing, China, 2:123-130. keynote lecture. 2nd International 121. Tian, Y. and M. J. Cassidy, (2013), 146. Youssef, B. S., Y. Tian and M.J. Cassidy Symposium on Frontiers in Offshore Equivalent absolute lateral static (2011). Probabilistic modes application Geotechnics, Perth, Australia, n/a: 87-123. stability of on-bottom offshore in the integrated stability analysis of pipelines, Australian Geomechanics 134. White, D. J. and M. S. Hodder offshore on-bottom pipeline. 30th Journal, under review November. (2010), A simple model for the effect International Conference on Offshore on soil strength of remoulding Mechanics and Arctic Engineering 122. Tian, Y. and M. J. Cassidy (2011), and reconsolidation, Canadian (OMAE2011): OMAE50047. Incorporating uplift in the analysis Geotechnical Journal, 47(7): 821-826. of shallowly embedded pipelines: 147. Zang, Z., L. Cheng, M. Zhao, D. Liang and Int. Journal of Structural Engineering 135. Wu, D., L. Cheng and M. Zhao (2010), B. Teng (2009), A numerical model for and Mechanics, 40(1): 29-48. Numerical and experimental study of onset of scour below offshore pipelines, natural backfill of pipeline in a Ocean Engineering, 56: 458-466. 123. Tran, D. S. and V. M. Tran (2010). under steady currents, International Propagation of buckle in subsea pipelines, 148. Zang, Z., L. Cheng and M. Zhao (2010), Conference on Ocean, Offshore and Arctic BE Thesis, University of Queensland. Onset of scour below pipeline under Engineering (OMAE2010), Shanghai, combined waves and current, International China, CD:OMAE2010-20325. 124. Wang, D., D.J. White and M.F. Randolph Conference on Ocean, Offshore and Arctic (2009), Numerical simulations of dynamic 136. Xiao, Z. G. and X. L. Zhao (2007), Current Engineering (OMAE2010), Shanghai, embedment during pipe laying on soft status of research into subsea pipelines China, CD:OMAE2010-20719. clay, 28th International Conference on subjected to fatigue loading, International Offshore Mechanics and Arctic Engineering, Institute of Welding Asian Pacific Congress, Honolulu, Hawaii, OMAE2009-79199. Stream 1 – Structures/Pipelines:Paper 1.34.

32 Subsea Pipeline Collaboration Cluster – final report 149. Zang, Z., L. Cheng and M. Zhao (2010). Onset 28th International Conference on Characterization, Monitoring and of scour below pipeline under combined Ocean, Offshore and Arctic Engineering Modelling of Geosystems, 179: 108-117. waves and current. 29th International (OMAE 2009), OMAE2009-79148. 160. Zhou, H. and M. F. Randolph (2009), Conference on Offshore Mechanics 155. Zhao, M. and L. Cheng (2010), Finite element Numerical investigations into cycling and Arctic Engineering (OMAE2010), analysis of flow control using porous of full-flow penetrometers in soft Shanghai, China, CD: OMAE2010-20325. media, Ocean Engineering, 37: 1357-1366. clay, Geotechnique, 59(10): 801-812. 150. Zang, Z. and L. Cheng (2012), Numerical 156. Zhao, M. and L. Cheng (2010), Numerical 161. Zhou, H. and M. F. Randolph (2009), simulation on sand waves behaviour and investigation of local scour below a Resistance of full-flow penetrometers their interaction with pipelines by ROMS vibrating pipeline under steady currents, in rate-dependent and strain-softening model, Ocean Engineering: submitted 2011. Coastal Engineering, 57: 397-406. clay, Geotechnique, 59(2): 79-86. 151. Zhao, M., L.Cheng and T. Zhou (2009), 157. Zhao, M. and L. Cheng (2010), Numerical 162. Zhou, H. and M. F. Randolph (2011), Numerical simulation of three-dimensional investigation of vortex-induced Effect of shaft on resistance of a ball flow past a yawed circular cylinder, Journal vibration of a circular cylinder close penetrometer, Geotechnique, 61 (11): 973-981. of Fluids and Structures, 25(5): 831-847. to a plane boundary., International 163. Zhou, T., H. Wang, S. F. Mohd Razali, 152. Zhao, M., L.Cheng and Z. Zang (2010), Conference on Ocean, Offshore and Y. Zhou and L. Cheng (2010), Three- Experimental and numerical investigation Arctic Engineering, OMAE2010, dimensional vorticity measurements in of local scour around a submerged vertical Shanghai, China, OMAE2010-21147. the wake of a yawed circular cylinder, circular cylinder in steady currents, 158. Zhao, M. and L. Cheng (2010). Three- Physics of Fluids, 22(1): 015108. Coastal Engineering, 57: 709-721. dimensional numerical simulation of 164. Zhu, H. and M. F. Randolph (2011), 153. Zhao, M. and L. Cheng (2008), Numerical hydrodynamic forces on an oblique cylinder Numerical analysis of a cylinder moving simulation of local scour below a vibrating in oscillatory flow. 17th Australasian through rate-dependent undrained soil, pipeline in currents, 4th International Fluid Mechanics Conference, Auckland, Ocean Engineering, 38(7): 943-953. Conference on Scour and Erosion, 233-239. New Zealand, Pen Drive: Paper 042. 165. Zhu, H. and M. F. Randolph (2010), Large 154. Zhao, M. and L. Cheng (2009), 159. Zhou, H., D.J. White and M.F. Randolph deformation finite element analysis of Experimental investigation of local (2008), Physical and numerical simulation submarine landslide interaction with scour around a submerged vertical of shallow penetration of a cylindrical embedded pipelines, International Journal circular cylinder in steady currents, object in soft clay, GeoCongress for Geomechanics, 10(4): 145-152.

Postgraduate Yue Yan Novel methods for characterising pipe-soil interaction profile forces in situ in deep water Yue’s thesis focused on establishing under vertical and torsional The ultimate aim of this research is to a theoretical understanding for the loading appropriate for toroid develop a theoretical understanding of response of a new class of seabed and ball penetrometer at shallow the behaviour of a shallowly embedded penetrometers – the toroid and ball embedment depths (b) allow spherical and toroid penetrometer penetrometers – designed specifically operative soil stiffness to be subjected to vertical and torsional for pipe-soil interactions without the estimated, or for the penetrometer loading, and to prove through physical difficulty of end effects. In view of the stiffness to be converted into modelling the concept of this new site perceived need to improve the pipe pipe-soil stiffness as required. characterisation tool focusing on axial design guidelines and develop more ◆◆Investigating the drainage of interaction between a pipeline and soil. reliable procedures for estimating soil during penetration and the axial interaction between pipe torsional loadings. The key effect and soil, this study explored toroid is to provide robust dissipation and ball penetrometer performance solutions specifically for these on clays through centrifuge model two new penetrometers, which tests and small strain finite element enables the measured pore analyses. There was also an emphasis pressure to be interpreted in on the axial interaction in isolation at terms of the consolidation shallow embedment ratio, but some characteristic of the soil. possible way of its incorporation Develop a testing framework and a into a more general interaction ◆◆ more reliable interpretation method modelling scheme are examined. for the near surface seabed soft soil. The aim of the research was to: ◆◆Provide recommendations on ◆◆Provide an improved quantitative the design of in these in situ framework to characterise the tools and associated testing undrained surficial soft sediments procedures which will lead to which will conclude (a) suggest more reliable and less conservative undrained resistance factors assessments of axial friction.

33 Key papers

Low, H..E., T. Lunne, K.H. Andersen, M.A. Sjursen, M.A., X. Li and M.F. Randolph. (2010). Estimation of intact and remoulded undrained shear strength from penetration tests in soft clays. Géotechnique, 60(11), 843-859.

Difficulties in obtaining high quality solutions to evaluate the influence compression. In the correlation soil samples from deep water sites have of particular soil characteristics. The between the remoulded penetration necessitated increasing reliance on overall statistics showed similar levels resistance and remoulded strength, piezocone, T-bar and ball penetration of variability of the resistance factors, the resistance factors for remoulded tests to determine soil properties for with low coefficients of variation, strength were found higher than those design purposes. This paper reports the for all three types of penetrometer. for intact strength and with slight results of an international collaborative However, correlations of the resistance tendency to increase with increasing project in which a worldwide, factors with specific soil characteristics strength sensitivity but insensitive high quality database of lightly indicated that the resistance factors for to soil index properties. Based on an overconsolidated clays was assembled the piezocone were more influenced assessment of the influence of various and used to evaluate resistance factors by soil stiffness, or rigidity index, soil characteristics, resistance factors for the estimation of intact and than for the T-bar and ball, while the are recommended for the estimation remoulded undrained shear strength effect of strength anisotropy was of intact and remoulded undrained from the penetration resistance of each only apparent in respect of resistance shear strength from the penetration device. The derived factors were then factors for the T-bar and ball relative resistances of each device for soil with compared with existing theoretical to shear strengths measured in triaxial strength sensitivity less than six.

q (kPa) q (kPa) qnet (kPa) T-bar ball 12 0500 1000 1500 2000 0500 1000 1500 2000 0 500 1000 1500 2000 0 10 m e

r 8 5 Burswood , r a

Chinguetti b - ( ) ( ) Chinguetti T

10 q 6

Chinguetti / r a b Onsøy - ( ) T ( ) ( ) Ariake 4 ( ) ( ) ( ) 15 q ( ) ( ) Burswood ( ) ( ) ) Chinguetti (m 2 ( )

h Ariake

t 20

p Yafrate and DeJong (2006) GOG 1 De Laminaria GOG 2 0 25 GOG 3 Norwegian Sea 12 GOG 4 Onsøy GOG 5 30 Burswood Laminaria GOG 6 10 Norwegian Sea Laminaria Chinguetti Burswood 1g model test 35 Norwegian Sea 8 GOG 1 1g model test m

e r , l 40 l a 6 b

(a) (b) (c) q / l l a

b 4 (a) Profiles of netq (b) profiles of Tq -bar (c) profiles of ballq q

2 Yafrate and DeJong (2006) 0 0 2 4 6 8 10 12

St

(a) Comparison between qT-bar/qT-bar,rem and strength sensitivity. (b) Comparison between qball/qball,rem and strength sensitivity.

34 Subsea Pipeline Collaboration Cluster – final report Key papers

Randolph, M. F., D. Seo and D.J. White (2010), Parametric solutions for slide impact on pipelines, Journal of Geotechnical & Geoenvironmental Engineering, 136(7): 940-949.

Pipelines are frequently subjected to the slide is equilibrated by membrane accuracy over a wide parameter range, active loading from slide events, both on tension in the pipeline in addition to and the net effect of the slide in terms land and in the offshore environment. the passive resistance. Various authors of stresses induced in the pipe wall Whether the pipeline is initially buried have explored this problem, and and maximum displacement of the or lying close to the surface, and these principles are well established. pipeline may be captured in appropriate whether it crosses the unstable region However, to date, no attempt has dimensionless groups. Design charts or lies in the path of debris originating been made to develop a standard set are presented for slide widths of up to from further away, the main principles of parametric solutions, which is the 1000 times the pipeline diameter, for are unchanged. The pipeline will purpose of the current paper. Both a practical range of other parameters be subjected to active loading over analytical and numerical solutions of such as the ratios of passive normal some defined length, related to the the problem have been developed, and frictional resistance to the active width of the slide, and as it deforms initially for slides acting normal to the loading. Although the solutions are will be restrained by transverse and pipeline but later extended to general limited by some of the idealisations, longitudinal resistance in adjacent conditions with the slide impacting they should provide a useful starting passive zones. Ultimately, the pipeline the pipeline at some angle. It is shown point in design, providing a framework may come to a stable deformed shape that analytical solutions based on for more detailed numerical analysis for where continued active loading from certain idealisations maintain their the particular governing conditions.

0.01 Note, order of curves is from centre outwards for qB/EA = the two B/D values, according to the legend 0.01 Combined 0.001

/E 0.0005

n, B/D = 10,000 i 0.001 0.0002 /E B/D = 100 ra 0.0001 , in

Tension ra

ed st 0.00005 st

ut 0.001

0.00002 ed ut mp 0.0001 p/q = 4, f/p =1 mp Co p/q = 0.5, f/p = 1 Co p/q = 0.5, f/p = 0.5 p/q = 0.5, f/p = 0.25 p/q = f/p = 0.5 p/q = 0.05, f/p = 0.25 0.00001 0.0001 10 100 1000 10000 0.00001 0.0001 0.001 0.01 Normalized debris flow width, B/D Slide loading, qB/EA

Effect of slide loading and width on maximum pipeline strains Variation of maximum combined strain with slide loading

35 Key papers

Hodder, M. S. and M. J. Cassidy (2010), A plasticity model for predicting the vertical and lateral behaviour of pipelines in clay soils, Geotechnique, 60(4): 247–263.

A complete theoretical model for The testing was conducted within to be made for various vertical and predicting the undrained behaviour The University of Western Australia’s horizontal load or displacement of a rigid pipe in clay soils when geotechnical drum centrifuge using combinations. However, it is limited to subjected to combined vertical and an element of pipe 10mm in diameter, monotonic loading and relatively small horizontal loading is described. 50mm in length and at an acceleration displacements. The model is verified in Physical modelling of a pipe on soft, 50 times the Earth’s gravity. The this paper by retrospectively simulating lightly overconsolidated kaolin clay model presented is expressed by a selection of combined loading tests was conducted, with the experimental the force resultants on the pipe and and comparing the output with the test program specifically designed the corresponding displacements experimentally recorded results to establish the model parameters. and allows predictions of response

UWA drum centrifuge used for pipeline testing

36 Subsea Pipeline Collaboration Cluster – final report Key papers

Tian, Y. and M. J. Cassidy (2008), Modelling of pipe-soil interaction and its application in numerical simulation, International Journal of Geomechanics, 8(4): 213-229.

This paper presents three plasticity for the behaviour within an allowable and their potential to investigate models that can be applied to combined loading surface. The first is generic pipeline system behaviour numerically simulate pipe-soil based on traditional strain-hardening is demonstrated. The applicability interaction. They can be applied plasticity theory and therefore assumes of the three models is interpreted individually to evaluate the force- purely elastic response inside a single theoretically and their differences displacement response of a small plane- expandable yield-surface. The second shown through application for (i) a strain pipe section or in combination allows some plasticity due to the use one pipe-soil interaction element, to simulate a long pipeline system. of a bounding surface, and the third and along (ii) a 100m segment of In the latter, numerous pipe-soil accounts for kinematic hardening pipeline. The latter shows the practical elements are attached to structural through the introduction of a second application of these models to offshore finite-elements, each simulating smaller surface. The models are detailed pipeline engineering examples, with localised foundation restraint along in this paper, allowing for simple the influence of a free span behaviour the pipeline. The three models are numerical implementation. Importantly, investigated. The ability to model increasing in sophistication, mainly due they are incorporated within the complex cyclic loading is also shown. to the manner in which they account structural analysis of a pipeline

Footing response of 30-m span

37 Key papers

Liu, H.B. and X.L. Zhao (2011), Predictions of fatigue life of steel connections under combined actions using boundary element method, The 21st International Offshore and Polar Engineering Conference, Maui, Hawaii, USA, 19-24 June, Volume 4, pp. 276-281

The fatigue life of girth weld is always boundary element method of analysis. were described clearly by the stress an important issue for subsea pipelines. Combined forces were applied in these intensity factors near crack-tip, the In this paper the method of numerical models: constant amplitude cyclic mode crack propagation rates and the fatigue modelling was used to study the fatigue I load and perpendicular static load. lives. The effect of perpendicular behaviours of subsea pipeline steel The numerical results were compared static load, stress ratio and stress connections. The analytical models were with the corresponding experimental range on fatigue behaviours were established using the software of BEASY, results and good agreements were evaluated through parametric study. which is developed on the basis of the achieved. Their fatigue behaviours

F1

Loading frame

Fh Fh

F1

Hydraulic to apply hoop force

Hand pump

Pipeline displacement after 3 hrs hydrodynamic loads

Footing response of 30-m span

38 Subsea Pipeline Collaboration Cluster – final report Key papers

Zhao, M. and L. Cheng (2010), Numerical investigation of local scour below a vibrating pipeline under steady currents, Coastal Engineering, 57: 397-406.

Local scour below a vibrating pipeline vibrations cause increases of scour scale of the scour. The shallower the under steady current is investigated by depth below the pipeline. The scour pit water depth is, the less time it requires a finite element numerical model. The underneath a two-degree-of-freedom to reaches the equilibrium state of scour. flow, sediment transport and pipeline vibrating pipeline is deeper than that It is found that the vibration forces response are coupled in the numerical under a pipeline vibrating only in the vortices to be shed from the bottom side model. The numerical results of scour transverse flow direction. The effects of the pipeline. Then vortex shedding depths and pipeline vibration amplitudes of water depth are also investigated. around a vibrating pipeline is closer to are compared with measured data The present numerical result shows that the seabed than vortex shedding around available in literature. Good agreement water depth has weak effect on the scour a fixed pipeline. This contributes to the is obtained. It is found that pipeline depth. However it does affect the time increase of the scour depth.

Mini –tube facility: 0.25m x 0.25m test section area

Time development of scour below a pipeline

39 Key papers

Albermani, F., H. Khalilpasha and H. Karampour (2011), Propagation buckling in subsea pipelines, Engineering Structures, 33(9): 2547-2533

The paper investigates buckle numerical results using finite element pipe, a faceted cylindrical geometry is propagation in deep subsea pipelines. analysis. The experimental investigation also investigated. Preliminary analysis of Experimental results using ring squash was conducted using commercial a faceted pipe shows that a substantial tests and hyperbaric chamber tests aluminium pipes with diameter-to- increase in buckling capacity can be are presented and compared with a thickness (D/t) ratio in the range of 20- achieved for the same D/t ratio. modified analytical solution and with 48. In contrast to conventional cylindrical

(a) (b)

Ring squash test RST

40 Subsea Pipeline Collaboration Cluster – final report Key papers

Senthilkumar, M. P. Rajeev, J. Kodikara, and N. I. Thusyanthan, (2011). Laboratory modelling of pipe-clay seabed interaction in axial direction, The 21st International Offshore and Polar Engineering Conference, Maui, Hawaii, USA, 19-24 June.

The current trend of bottom embedding axial walking and lateral buckling, works obtained from literature are of offshore petroleum pipelines is relevant to the axial and lateral detailed and modelling techniques are increasingly being challenged by the components of interaction. This paper reviewed. Finally, the development expansion of the pipeline at elevated summaries current knowledge on the of the Monash Advance Pipe testing operating conditions of temperature and axial resistance of surface laid pipes, System (MAPS) for further investigating pressure. For simplicity, the expansion in general, the pipe-soil interaction axial response is explained and the challenges could be classified into in axial direction. The experimental testing methods are discussed.

Monash Advanced Pipe Testing System (MAPS) in action

Monash Advanced Pipe Testing System (MAPS)

41 Key papers

Wang, D., D.J. White and M.F. Randolph. (2010), Large deformation finite element analysis of pipe penetration and large-amplitude lateral displacement, Canadian Geotechnical Journal, 47(8): 842-856.

Seabed pipelines must be designed using a large deformation finite element the soil strength. For ‘light’ pipes, the to accommodate thermal expansion – (LDFE) method, with a strain-softening, pipe rises to the soil surface and the which is commonly achieved through rate-dependent soil model being soil failure mechanism involves sliding controlled lateral buckling – and to incorporated. The calculated soil flow at the base of the berm. In contrast, resist damage from submarine slides. mechanisms, pipe resistances and ‘heavy’ pipes dive downwards and In both cases, the pipe moves laterally trajectories from the LDFE analyses a deep shearing zone is mobilised, by a significant distance and the overall agree well with upper bound plasticity expanding with continuing lateral pipeline response is strongly influenced solutions and centrifuge test data. It movement. The different responses by the lateral pipe-soil resistance. This is found that the lateral resistance is are reconciled by defining an ‘effective resistance is affected both by the soil strongly influenced by soil heave during embedment’ that includes the effect of conditions and also the weight of the penetration and the berm formed the soil berm or wall ahead of the pipe. pipe, since the longitudinal flexibility ahead of the pipe during lateral pipe The relationship between normalised allows the pipe to move vertically while displacement. Two distinct modes of lateral resistance and effective being pushed or dragged laterally. In this behaviour are evident, depending embedment is well fitted using a power paper, the process of pipe penetration on the weight of the pipe relative to law, regardless of the pipe weight. and lateral displacement is investigated

-1 -1 u/D=0.5 u/D=0.01 -0.5 -0.5

0 0 D D z/

z/ 0.5 0.5

1 1

(a) (b) 1.5 1.5

-1.5 -1 -0.5 0 0.5 1 1.5 -2.5 -2 -1.5 -1 -0.5 0 0.5 x/D x/D -1.5 u/D=1.0 -1.5 u/D=2.0 -1 -1 Equivalent plastic strain around pipe after vertical penetration (w/D = 0.45) -0.5 -0.5 D z/ 0 D z/ 0

0.5 0.5

(c) (d) 1 1

-3 -2.5 -2 -1.5 -1 -0.5 0 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 x/D x/D Soil flow mechanisms for a heavy pipe R( = 1.25)

42 Subsea Pipeline Collaboration Cluster – final report Key papers

Boylan, N., C. Gaudin, D.J. White and M.F. Randolph (2010), Modelling of submarine slides in the geotechnical centrifuge, 7th International Conference on Physical Modelling in Geotechnics (ICPMG 2010), Zurich, Switzerland CD:1095-1100.

The depletion of near shore hydrocarbon dependent on the security of the Western Australia. This facility uses resources has led to a move to installations and tie-backs to shore, the long, narrow channel of the drum exploration and production in deep which are susceptible to geohazards centrifuge to model the run-out of and ultra-deep waters. This shift into such as submarine slides. The Centre submarine slides that are triggered deeper waters requires increased for Offshore Foundation Systems (COFS) from an intact block of clay, along a reliance on sub-sea installations and has initiated research to investigate the model seabed. This paper describes pipelines that can extend to more than impact of submarine slides on offshore the development of the apparatus to 500km from shore, often across areas pipelines. As part of this project, a trigger the slides in the drum centrifuge of changing seabed morphology and facility has been developed to model and presents some results from the continental shelves. The viability of submarine slides in the geotechnical first tests conducted in the facility. these developments is increasingly drum centrifuge at the University of

Sliding door Paddle

Legend

intact block of clay Counter mass Slide triggering device

Slide box CLD gantry Slide run-out

Cross-section of drum centrifuge equipment for slide modelling

43 Key papers

Baldock, T. E. and J. K. Seelam (2009), Numerical and physical modelling of tsunami run-up and impact on subsea pipelines, 1st Annual Society for Underwater Technology Subsea Technical Conference (SUT), Perth.

This paper presents initial results from on the and on the results of the experiments which aim experimental and numerical modelling continental slope are also examined. to simulate conditions corresponding of tsunami wave propagation over the to the continental shelf slope and The experimental measurements continental slope and near shore region. particularly the near shore zone, where include data covering non-breaking and The paper considers the potential tsunami breaking may generate high breaking tsunami-type waves obtained impacts of tsunami waves on subsea horizontal pressure gradients over from the large-scale Tsunami Wave pipelines, which may be indirect i.e. the large areas of the seabed. Novel shear Basin at Oregon State University. Initial triggering of submarine landslides or cell measurements will be made to experimental measurements of sea bed turbidity currents. The project will also investigate the relative contribution and bed shear stresses will consider how the complex bathymetry of shear stress and pressure gradients be presented from the University of around pipelines may change the fluid to submarine slide initiation. Tsunami Queensland tsunami wave flume, which loading, and it will also examine the kinematics within submarine canyons will subsequently be used to investigate potential loads induced by internal may amplify the tsunami motion and the potential for tsunami-induced waves. The modelling encompasses both flow velocities and is also of concern. liquefaction of the sea bed around overland flow processes and the seabed The experimental results will be used pipelines and the potential for tsunami pressures and shear stresses induced to further refine numerical modelling to trigger submarine landslides. The by tsunami waves. Likely conditions of tsunami and to develop models. paper provides an overview and initial

OSU tsunami wave basin

44 Subsea Pipeline Collaboration Cluster – final report Key papers

Pusey, G. and A. Duncan (2009), A preliminary study of underwater acoustic communications over horizontal ranges, 1st Annual Society for Underwater Technology Subsea Technical Conference (SUT) Perth, CD.

Difficulties in subsea data telemetry stem applications, communications over transmission over long ranges. This is from issues to do with electromagnetic a large horizontal range are subject followed by preliminary results from wave penetration and procedures to many complications. This study propagation models and trials off the involved in deploying and maintaining investigates the various mechanisms coast of Western Australia. cabled solutions. While acoustic affecting acoustic propagation, modems are increasingly useful in many specifically those important for data

(a) (b)

Summary of deployment results showing modem performance over range (a) and the corresponding signal strength data detected by the ambient noise recorder (b).

45 Awards

Pipeline industry awards:

Australian Gas Innovation Award Commendation Bassem Youssef received the Australian Gas Innovation Award Commendation. He was recognised for his unique pipeline on-bottom stability simulation program, developed as part of his PhD study. This provides pipeline engineers with a reliable and accurate pipeline design tool capable of a 3D simulation of offshore pipelines under the action of wave and current loading. Bassem was supervised by Mark Cassidy and Yinghui Tian.

> Bassem Youssef

Postgraduate student awards: Benthic Scholarship: Han Eng Low • Hamed Mahmoodzadeh Poornaki SUT Scholarship: Bassem Youssef AusAid Scholarship: Siti Fatin Mohd Razali

46 Subsea Pipeline Collaboration Cluster – final report Pipeline industry awards:

Industry Innovation and Technology prize and Innovation and Development category of the 2012 WA Engineering Excellence Awards Cluster Chief Investigators Liang Cheng and David White, along with Scott Draper and Hongwei An won the Innovation and Development category of the 2012 WA Engineering Excellence Awards for the O-Tube Program, which simulates the effects of cyclone on subsea pipelines. The O-Tube also won the Subsea Energy Australia Industry Innovation and Technology Award. The research is crucial for Australia’s massive oil and gas industry, which plans to install an estimated 3000km of offshore pipelines worth more than $15 billion over the next 10 years. > David White with the beam centrifuge

Researcher awards: Whitfield Scholarship: Hongjie Zhou Australian Academy of Science’s Anton Hales medal: David White ARC Future Fellowships: David White • Mark Cassidy 2011 E.H. Davis Lecturer: Mark Cassidy 2011 WA young scientist of the year: David White

47 Keynote presentations, invited lectures and papers

Boylan, N. P. and D. J. White (2010). Randolph, M. F., D. Wang, H. Zhou, White, D.J. and C. Gaudin (2009). Geotechnical frontiers in offshore M.S. Hossain and Y. Hu (2008), Physical modelling techniques engineering – invited keynote lecture. Large deformation finite element developed within the Cluster and the International Symposium on Recent analysis for offshore applications, resulting advances in pipeline analysis Advances and Technologies in Coastal 12th International Conference of techniques, International Workshop Development, Tokyo, Japan, CD: 18 pages. International Association for Computer on Geotechnical Modelling, Tongji Methods and Advances in Geomechanics University, China, November 2009. Cassidy, M.J. (2009). Engineering (IACMAG), Goa, India, CD: 3307-3318. for a new generation of offshore White, D. J. and D. N. Cathie (2011). production. ATSE Focus. Vol. 154, White, D.J. (2008). Geotechnical Geotechnics for subsea pipelines – a Australian Academy of Technological design of seabed pipelines, keynote lecture. 2nd International Sciences and Engineering, pp. 21-22. European Symposium on Centrifuge Symposium on Frontiers in Offshore Modelling, London, May 2008. Geotechnics, Perth, Australia, n/a: 87-123. Cassidy, M.J. (2009). Foundations for Australia’s offshore oil and gas White, D.J. (2009). Recent advances in installations, WA Chapter of the pipeline geotechnics made through Australian Academy of Technological centrifuge modelling at UWA, Deltares, Sciences and Engineering, 10 June 2009. The Netherlands, December 2009. Cassidy, M.J. and Y. Tian (2011). Development and application of models for the stability analysis of Australia’s offshore pipelines. Proc. 2011 Symposium on Coastal and Marine Geotechnics: Foundations for trade, 15th Annual Symposium of the Australian Geomechanics Society, Sydney, Australia. Hao H. (2009). SHM research in UWA, Guangzhou University, China, 2009. Randolph, M.F., C. Gaudin, S. Gourvenec, D.J. White, N. Boylan and M.J. Cassidy (2011), Recent advances in offshore geotechnics for deepwater oil and gas developments, Ocean Engineering. Randolph, M. F. and D. J. White (2008), Offshore foundation design – a moving target. Keynote paper, 2nd International Conference on Foundations (ICOF), Bracknell, UK, 27-59.

48 Subsea Pipeline Collaboration Cluster – final report Hosting the Second International Symposium on Frontiers in Offshore Geotechnics

Pipeline engineering and the research of the Subsea Pipeline Collaboration Cluster was highlighted at the Second International Symposium on Frontiers in Offshore Geotechnics (ISFOG), hosted by the Centre of Foundation Systems at the University of Western Australia, Perth, between 8 and 10 November 2010.

The ISFOG symposium provided a The technical themes of the symposium platform for academics and practitioners were selected to reflect the key stages to discuss and exchange ideas to address of an offshore project. They ranged from the emerging challenges in offshore assessing offshore geohazards with and showcase state-of-the-art geophysics and in situ state-of-the-art offshore geotechnics. geotechnical testing techniques, through to design considerations for foundation ISFOG 2010 was opened by Ann solutions and pipelines, culminating in Pickard, the Country Chair of Shell in key considerations involving design risk. Australia and Executive Vice President of Shell Upstream Australia. Professor David White delivered the keynote lecture, and international The symposium attracted 306 delegates practitioners and academics presented from 24 countries representing industry 14 papers on pipeline engineering. and academia. These can be found in the proceedings.

Ann Pickard, Country Chair of Shell, at the opening of ISFOG 2010 with Mark Cassidy

Christophe Gaudin giving a tour of the beam centrifuge during ISFOG2010 ISFOG2010 proceedings

49 The Subsea Pipeline Collaboration Cluster combined the capabilities of:

◆◆The University of Western Australia ◆◆Curtin University of Technology ◆◆The University of Queensland, Brisbane Monash University, Melbourne, Victoria

The partners ◆◆ ◆◆The University of Sydney ◆◆Flinders University, Adelaide ◆◆CSIRO Wealth from Oceans Flagship.

50 Subsea Pipeline Collaboration Cluster – final report The Flagship Collaboration Fund enables the skills of the wider Australian research community to be applied to the major national challenges targeted by the CSIRO’s National Research Flagship Program. As part of the $305 million provided over seven years by the Australian Government to the National Research Flagships, $97 million was allocated specifically to enhance collaboration between the CSIRO, Australian universities

Flagship Collaboration Fund and other publicly funded research agencies. The Australian Government’s budget announcement in 2007 provided additional resources for the fund. The Subsea Pipeline Collaboration Cluster contributes to the Wealth from Oceans Flagship. The program aims to work with industry to develop the science and technology to unlock new opportunities in the exploration and development of Australia’s offshore hydrocarbon resources. The cluster consisted of a $3.6 million grant through the Flagship Collaboration Fund and in- kind contributions totalling $7.4 million from the participating universities.

51 52 Subsea Pipeline Collaboration Cluster – final report 53 Contact us For further information t 1300 363 400 Flagship Collaboration Cluster leader +61 3 9545 2176 Winthrop Professor Mark Cassidy e [email protected] Director – Centre for Offshore Foundation w www.csiro.au Systems, University of Western Australia M053 Your CSIRO 35 Stirling Highway Australia is founding its future on Crawley WA 6009 science and innovation. Its national t +61 8 6488 1142 science agency, CSIRO, is a powerhouse f +61 8 6488 1104 of ideas, technologies and skills for e [email protected] building prosperity, growth, health and sustainability. It serves governments, CSIRO industries, business and communities Ian Cresswell across the nation. Science Director, Wealth from Oceans National Research Flagship, CSIRO GPO Box 1538 Hobart TAS 7001 t +61 3 6232 5213 f +61 3 6232 5125 e [email protected]