VGP Technical Report 18 - A review of the Penryn gas field Onshore Otway Basin, Victoria
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Product description:About the Victorian Gas Program: The Victorian Gas Program (VGP) is a comprehensive science-led program, incorporating geoscientific and environmental research to assess the risks, benefits and impacts of potential onshore conventional gas exploration and production. The program is also investigating the potential for further discoveries of onshore conventional and offshore gas in the Otway and Gippsland geological basins and assessing the feasibility of additional onshore underground gas storage in depleted reservoirs around the Port Campbell area. The VGP includes an extensive, proactive and phased community and stakeholder engagement program, through which the results of the scientific studies are being communicated. Executive summary: The opportunity for further underground gas storage (UGS) in depleted gas fields in the onshore Otway Basin is being investigated as part of the Victorian Gas Program (VGP). There are currently three depleted gas fields used for UGS in Victoria. These sites are in the Port Campbell area in the onshore Otway Basin. The Geological Survey of Victoria (GSV) engaged SEAL Energy Pty Ltd (SEAL Energy) to carry out a suite of technical studies to investigate the potential for further underground gas storage at existing depleted gas fields and known unproduced fields in the onshore Otway Basin. Six sites, including Penryn, have been selected through a ranking process (Bagheri, 2019) for static and dynamic modelling. To guide the static and dynamic modelling, data from the Penryn field was reviewed to provide further insight into the nature of the geological structure including the potential for connectivity across the field and inputs for probabilistic original gas in place (OGIP) calculations. Analysis of geological structure maps and stratigraphic, fluid and pressure data from Penryn-1 and Penryn-2 were integrated to examine evidence for gas continuity between the two wells and to determine if they form one contiguous or two discrete gas accumulations. Wellhead pressure data suggests that Penryn-1 and Penryn-2 may not be connected. Analysis of strata across the south bounding fault of the Penryn complex indicates that connection between the porous layers may explain breaching to form two discrete pools. As part of the underground gas storage project, dynamic modelling will provide a better understanding of the structure by testing the areal extent of the closure and by history matching the production volumes and pressure data. Bibliographic reference: SEAL Energy, 2020. A review of the Penryn gas field, Onshore Otway Basin, Victoria. Victorian Gas Program Technical Report 18. Geological Survey of Victoria. Department of Jobs, Precincts and Regions. Melbourne, Victoria. Download: The downloadable version of this report is supplied in PDF format (6.2 MB) and accessible version (DOCX 14.3 MB). | ||||||
