A major aim of this research cluster is to facilitate extraction of oil and gas reserves in the most optimal and sustainable manner. The goal is to reduce the emissions and costs associated with the industries and over the longer-term to allow cleaner alternatives, such as gas, to displace coal-fired electricity.
The Department of Nuclear Physics, Research School of Physics and Engineering, at the ANU hosts the largest ion accelerator in Australia. The high energies provided by the 14UD accelerator allow Accelerator Mass Spectroscopy (AMS) measurements of the isotope 36Cl at a sensitivity that is unparalleled around the globe. Measurements of 36Cl provide useful insight into the large scale structure of oil and gas fields in a number of ways.
Cosmic rays initiate nuclear reactions in the atmosphere to continuously produce trace quantities of the radioactive isotope 36Cl. The atmosphere also contains stable chlorine isotopes derived from sea spray and re-mobilised terrestrial salts. This results in a characteristic 36Cl/Cl ratio for a given location, and rain water that enters the groundwater system is thus labelled by the 36Cl/Cl ratio. Radioactive decay of 36Cl can then be used as a clock to date basin water residence times from a few thousand to a few million years, giving information on the source, origin and recharge rates of underground aquifers. In collaborations with the Queensland government Department of Natural Resources and Mines, and with researchers at CSIRO, the University of Queensland and the Queensland University of Technology we are currently using 36Cl AMS measurements to investigate and understand the hydrology of Australian Coal Seam Gas prospects to allow optimal development of the gas extraction process.
In the oil sector, the Department of Nuclear Physics has also had a long industry collaboration with Statoil of Norway (now Equinor) through its partner IFE (Institutt for Energiteknikk), and more recently with ResTrack (a spin-off company of IFE). Artificially produced 36Cl (made in nuclear reactors) was injected in seawater into the oil-bearing strata at injection wells in the North Sea oil field. Brine accompanying oil from production wells in the vicinity was then analysed for 36Cl content using AMS. The first appearance and subsequent time development of the 36Cl signal provides information on the recoverable reserves, well-to-well communication and on the oil field heterogeneity. The data obtained make a significant contribution to the efficiency and effectiveness of the oil extraction program.
Similarly, researchers in the Department of Applied Mathematics, Research School of Physics and Engineering, have been working for over a decade with many of the largest petroleum companies in the world to better understand the physics of fluid flows at the sub-millimetre scale (between grains in sedimentary rocks). These studies also contribute to improved understanding of the fundamental processes underpinning shale gas extraction and can help quantify the risks of environmental damage and fugitive CO₂ emissions. Much of the science and technology in this area is in common with that required for geologic storage of CO₂ and therefore research in this area overlaps with work done as part of ECI’s Carbon Capture and Storage research cluster.