CSIRO scientists from the Divisions of Land and Water and Petroleum have achieved an international advance in the hunt for oil and gas that will lower the costs and risks of exploration and production.
An increasingly large part of the nation’s petroleum reserves lies in the deep rock formations of Western Australia’s Northwest Shelf oil and gas fields. Displacements in the rock formations called faults can act as barriers to fluid flow and allow the oil and gas to accumulate and pressure to build-up.
But these faults can also leak – allowing oil and gas to escape from their reservoir.
Backed by eleven of the nation’s major petroleum resources companies, as well as the Australian Geological Survey Organisation (AGSO) and the Western Australian Government, Dr Najwa Yassir and Dr Claus Otto have found an answer to the problem.
They have devised a method for assessing which faults are sealing or non-sealing, which reservoirs are leaking and a way to forecast where the petroleum is likely to end up, using science developed to study the movement of deep underground water.
"Our aim was to use applied hydrogeology to find which faults on the Northwest Shelf will seal tight and hold the oil or gas, and which ones will leak," Dr Otto explains.
By studying the dynamics of these underground flows, using similar techniques to those used by hydrogeologists to monitor groundwater, Dr Otto and Dr Yassir say it is possible to assist the petroleum industry in locating potential accumulations. This reduces the financial risk and saves both exploration and production costs.
"The physics of the flows is the same for both oil and water," Dr. Otto explains, "and what we have learned from studying the behaviour of underground water can also be applied to oil. So oil and water really do mix, in terms of the science at least."
The CSIRO advance, which is helping in exploration risk reduction of major new oil resources in Australia, also enables oil companies to estimate with much greater accuracy the size and characteristics of the fields they are exploiting – and so make a better prediction of their productive life.
In the course of their research the team will produce a major hydrodynamic database for two of Australia’s largest energy fields – the Carnarvon basin and Timor Sea – which will be available for companies exploring for, or producing, oil and gas in the region.