News _________________________________________
| The quest to rescue 'stranded' gas fields |
| Tuesday, 12 August 2008 | |
By Jason Major
Photo by Evan Collis
Flagships target clearly defined goals, framed from a deep analysis of the needs of people and enterprises. Flagships operate on a larger scale and longer timeframes, and have a stronger focus on impact and adoption than previous initiatives. The Flagship Collaboration Fund unites capabilities from across CSIRO with expertise from partners in universities, other research agencies and industry. Up to 50 per cent of Australia's gas resources (about 140 trillion cubic feet), worth an estimated $1 trillion in today's terms, exist in these remote fields, and there could be vast quantities more in Australia's extended continental shelf, recently announced by the United Nations. But to reach them requires radically new and cost-effective technologies. Principal among these is to dispense with the traditional platforms that dominate the offshore oil and gas industry and instead place installations on the sea floor and in the well-hole itself. These would be connected to the shore by large pipelines laid along the seabed. CSIRO's Wealth from Oceans Flagship has begun work on this potential new era of exploration through its platform-free fields program. One of the key tasks is to find a way to design and construct the undersea pipelines that can start in depths exceeding 1000 metres and then traverse the long (up to 300km), and often mountainous, undersea terrain from the well, across the continental shelf, and to the shore. To overcome these design challenges, the Wealth from Oceans Flagship has formed, within its platform-free fields program, a Collaboration Cluster on Subsea Pipelines. The cluster combines the research capabilities of the University of Western Australia (UWA), Curtin University of Technology, the University of Queensland, Monash University, the University of Sydney and Flinders University . Despite all this gas within tantalising reach, CSIRO's leader of the platform-free fields program, Dr Edson Nakagawa, says the next decades will see an imbalance in the supply and demand for hydrocarbon resources in Australia, unless these stranded resources are accessed. “To succeed in this research venture will require the integration of our scientific capability with the best research and development groups worldwide and strong industry partnerships,” Dr Nakagawa says. The platform-free fields program has secured some early industry involvement. Companies worldwide were consulted to establish their needs and areas of interest. “Most projects within the collaboration cluster also have industry support, and as new projects are developed, industry is getting more involved,” he says. “The proximity to industry will be what allows our technology to be implemented.” UWA has also gained funding from a consortium of oil and gas industry players and the WA Government. The Australian program may also be able to draw on similar research being done internationally. The $10 billion Ormen Lange gas field in the Norwegian Sea, which came online in 2007, is one example. The project involved laying 24 subsea wellheads and a 1200km pipeline (the world's longest) at depths of 1000 metres, which climbed towards the shore over a ragged maze of 200-foot peaks and 35-degree hills. However, Dr Nakagawa says that although technologies are available to construct such pipelines, generally their application to other gas fields is still not feasible and many of the models used for their design still need improvement. “The whole industry needs to explore deeper and more remotely to access new oil and gas. And to make this viable, costs need to be lowered. Reducing the size and cost of platforms and, eventually, eliminating them is a sensible way of doing this.” CSIRO estimates platform-free technology could save industry about 75 per cent of the initial capital investment and ongoing operational costs associated with offshore platforms. But Dr Nakagawa says that a changing seabed morphology and the continental shelf present a unique set of technological challenges for each of Australia 's remote, deep-water resources. To assess Australia 's research capabilities in this area, CSIRO d a year-long due diligence study to map available expertise against industry needs and to identify gaps that need to be filled before the platform-free fields concept can become a reality. The pipeline cluster comprises six projects, including research on deep-water seabed sediments; assessment and mitigation of hazards such as sand movements, landslides and tsunami-induced seabed pressures that can affect pipeline integrity; development of analysis tools to determine safe routes for pipelines; risk assessment models; and real-time remote monitoring of pipeline health and stability. Professor Mark Cassidy is the cluster leader and director of UWA's Centre for Offshore Foundation Systems (COFS). COFS has large research initiatives that tackle the challenges associated with developing oil and gas reserves in deep water. This includes expertise in the design of pipelines. For example, Professor Cassidy says industry will need to predict loading conditions on the pipe, when and where it might buckle or displace, and how much resistance the pipe will experience. One of the tasks that COFS will be doing for the cluster is developing models that engineers can use to predict pipeline behaviour under these stresses. “We need to provide industry with the ability to evaluate and plot the best route for the pipeline,” Professor Cassidy says. “That is, which route will be the most economical, but also minimise any risk from landslides, strong currents, seabed movement and other geo and environmental hazards. “In some areas, such as those exposed to certain geohazards, current technology can only provide a qualitative assessment of the level of risk. We aim to develop state-of-the-art numerical analysis models to quantify it. “In other words, instead of having simply a high or low risk associated with specific hazards you can say, for example, there is a 0.1 per cent risk of failure within the lifetime of the pipeline. Such precise modelling reduces uncertainties and risks, leading to less conservative assumptions and design limits and consequently lower costs and greater feasibility.” The models will be informed by physical testing. However, field experiments on offshore pipelines are not feasible because of their enormous size. Researchers at COFS will test reduced-scale models of pipelines in Australia 's only geotechnical centrifuge facility. By spinning the soil and reduced-scale pipelines to accelerations of up to 200 times that of Earth's gravity, they can accurately simulate the stresses that the soil around the pipeline will experience and produce true-scale models. The centrifuge's high gravitational forces can also simulate in a few hours the behaviour of the seabed that would naturally happen over years. In a deep-water environment, pipelines are located where human teams cannot easily reach, so reliability of the infrastructure and the associated monitoring and detection technologies is paramount. A breakage of the pipeline could cost millions of dollars and potentially leak oil and gas into the environment. The monitoring and detection tools need to predict the location and likelihood of a possible fault and, if a problem occurs, be able to remotely and quickly detect and isolate the problem or, where necessary, shut the system down. “We need to ensure that the tools we provide to industry can build, monitor and maintain a pipeline to withstand the rigours of the harsh marine environments and avoid this disaster scenario altogether,” Professor Cassidy says. In its Energy in Australia 2008 report, ABARE projects that fossil fuels will meet the bulk of Australia 's energy needs, accounting for the majority of primary energy consumption to 2030. A 2004 oil and gas report from Geoscience Australia estimated Australia 's consumption of crude oil and gas in 2005 could be sustained with its existing economically obtainable resources for about 10 years. After this time, the imbalance in supply predicted by Dr Nakagawa will start to have an effect. However, Dr Nakagawa expects that by 2020 new enabling technologies resulting from the Flagship's and similar research will help unlock about 25 per cent of Australia 's stranded resources. “Although the technologies arising from this cluster are designed to help with issues specific to Australian conditions, they will help build a local knowledge industry, and many will be applicable worldwide and available for export along with the accumulated knowledge,” says Wealth from Oceans Flagship director Dr Kate Wilson. “The cluster's research needs to increase the attractiveness to industry of such investment. Otherwise, competing opportunities overseas could be of more interest to these companies.” A story provided by CSIRO Solve - A CSIRO Review of scientific innovations for Australian industry. This article is under copyright; permission must be sought from CSIRO Solve to reproduce it. |
