Factors controlling tight gas sandstone reservoir quality in the Whicher Range gas field, Southern Perth Basin, Western Australia*
C. Orsini A , R. Rezaee A and M. Wilson ACurtin University of Technology.
The APPEA Journal 51(2) 741-741 https://doi.org/10.1071/AJ10121
Published: 2011
Abstract
There are limited studies characterising the Willespie Formation, a Permian tight gas sandstone in the southern Perth Basin of Western Australia. Consequently, the main factors controlling the reservoir quality, lateral reservoir connectivity and fluid flow mechanism remain unknown. Available data from five Whicher Range wells—including wireline logs, seismic, core data, well reports and petrographic data—were studied to define the syn-depositional and post-depositional events affecting the reservoir rock quality.
Based on analysis of the aforementioned data, the Willespie Formation is interpreted to have been deposited under predominantly fluvial conditions in an ancient rift basin of continental origin with no marine influence. The sedimentary environments were laterally varied, as inferred from discontinuous facies formed by meandering channels, crevasse splay and flood plain settings that were mainly controlled by the Permian tectonic setting.
Extensive compaction due to ductile grain deformation, as well as clay and calcite cements—filling pores and replacing grains—are the main post-depositional factors affecting the reservoir quality of the medium–coarse-grained, poorly sorted litharenitic sandstones of the Willespie Formation. Combined syn-depositional parameters—controlling the composition and the texture of the sandstone—and post-depositional diagenetic events have had a critical control on the distinctive poor porosity (8% average) and very low permeability of this tight gas sandstone reservoir.
Cesar Orsini is a PhD candidate at Curtin University and a member of the unconventional gas research team in the Department of Petroleum Engineering at Curtin University. He received his BSc (geological engineering) at UCV (Central University of Venezuela) in 2004. Prior to joining Curtin University, Cesar’s experiences cover work as a geologist and wellsite geologist, developing 3D geological modelling and geological operations for conventional oil, coal and heavy oil projects. His research interests lie in the understanding of reservoir characterisation and geological reservoir modelling for conventional and unconventional reservoirs. |
Reza Rezaee is an associate professor at Curtin’s Department of Petroleum Engineering and has a PhD in reservoir characterisation. He has more than 20 years’ experience in academia and industry. During his career he has been engaged in several research projects supported by national and international oil companies. These commissions, together with his supervisory work at various universities, have involved a wide range of achievements. He has supervised more than 50 MSc and PhD students during his university career to date. His research has been focused on integrated solutions for reservoir characterisation, formation evaluation and petrophysics. He has used expert systems such as artificial neural networks and fuzzy logic, and has introduced several new approaches to estimate rock properties from log data where conventional methods failed to succeed. He is presently focused on unconventional gas including gas shale and tight gas sand studies, and is the lead scientist for the WA:ERA (EIS) Tight Gas and shale gas research projects. |
Moyra Wilson is a research and teaching fellow in the Department of Applied Geology, Curtin University (since late 2007), specialising in past environmental change, carbonate and sedimentary systems, and their reservoir quality. Prior to her move to Australia, Moyra held a lectureship at Durham University, UK (1999–2007) and was a postdoctoral researcher at Birkbeck and then Royal Holloway Colleges (London; 1995–9), leading industry-funded research on carbonate reservoir development in southeast Asia. She is an honours graduate in geology (Cambridge, UK), was awarded her PhD in carbonate sedimentology from London University (1995) and holds a higher education teaching qualification from Durham University (2002). Moyra has authored more than 50 scientific papers and reports, supervised more than 30 postgraduate and honours students, and received awards for excellence in sedimentary research (Including the Lyell Fund from the Geological Society of London). Her present teaching duties include delivery and co-ordination of units in sedimentary and petroleum systems. Her research is focused on understanding major controls affecting the evolution and reservoir quality of tropical marine, and other sedimentary systems. She works with the oil and gas industry on applied projects and funding for research has come from numerous companies and grant bodies. |
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