Revisiting the rocks discovers turbidites and a new exploration play in the Penola Trough, Otway Basin, South Australia
Sharon Tiainen A * , Rob Kirk B , Chris Cubitt A and Tim Rady CA
B
C
Sharon Tiainen is a graduate of the University of Adelaide and has an Honours degree in petroleum geology and geophysics. She has over 25 years’ experience in the upstream oil and gas industry having worked in exploration, appraisal, development, and production roles. She has worked acreage in Algeria, Austria, Australia, Ecuador, Germany, India, Libya, Malaysia, Morocco, Myanmar, the Netherlands, Norway, Papua New Guinea, Pakistan, the Philippines, Romania, Tunisia, Turkey, the UAE, and the United Kingdom. In 2009 she established her own company and most recently she joined the South Australia Department for Energy and Mines and is a member of EAGE, SPE and PESA. |
Rob Kirk graduated from the University of Adelaide (BSc Hons) and the University of WA (MSc) – combining geology with geophysics. He has four decades of industry experience in seismic and sequence stratigraphy having worked with SA Oil and Gas, Occidental, BHP, and Woodside as well as 20 years consulting. He has worked some 40 basins worldwide. Rob has given public and inhouse industry courses on seismic stratigraphy for 30 years. Rob jointly won the 1991 AAPG Best Paper Award, was 1993 and 2014 PESA Distinguished Lecturer, 1994 Keynote Speaker at GCSSEPM, Houston and has had regular articles in the PESA Journal. He is a member of PESA and the AAPG. |
Dr Chris Cubitt graduated from the University of Adelaide with a PhD in clastic diagenesis and sedimentology. He has more than two decades of industry experience in reservoir and regional geology working basins worldwide. In early 2023 he joined South Australia’s Department for Energy and Mining as a Deputy Director. Chris is an author of more than 20 publications, and is a member of PESA, IAS and the EAGE. |
Tim Rady is a geophysicist with 18 years’ experience in the oil & gas industry, specialising in seismic interpretation, play analysis, prospect maturation and opportunity evaluation. He has worked for Santos, Premier Oil and Total Energies on a broad range of new ventures, exploration and development projects across Australia, SE Asia, Brazil, PNG, Bangladesh, and Norway. Tim currently consults to the E&P industry and is leading the subsurface technical aspects of entX Limited’s underground hydrogen storage project. Tim holds a BSc (Hons) in Petroleum Geophysics from the Australian School of Petroleum and an MBA from the London Business School. |
Abstract
As part of an integrated geological, geochemical, and geophysical study, conventionally cored intervals from the lower-most stratigraphic section of the onshore South Australian part of the Penola Trough, Otway Basin have been reviewed and reinterpreted. Three conventionally cored wells; Bungaloo-1, Jolly-1ST1 and Sawpit-2, were described using a quick-look approach to determine gross lithological and sedimentological information. Seven lithology types were observed: clay-siltstone with horizontal lamination, diamictite (claystone with horizontal lamination and dropstones), clay-siltstone with massive-horizontal lamination, silt-sandstone with horizontal lamination, sandstone with ripple lamination, sandstone with parallel lamination and sandstone with massive bedding ± rip-up clasts. The first two lithologies are interpreted as representing deposition in a cold climate, profundal-lacustrine depositional environment. The first, containing interpreted varves is the most distal and the second, containing dropstones indicates relatively colder freeze/thaw conditions. The last five lithologies are interpreted as lacustrine turbidite depositional environments, specifically Bouma sequences Te, Td, Tc, Tb and Ta, respectively. Seismic facies interpretation has identified canyon-like and mound features and interpreted them as slope-feeder channels and fan/s respectively, at and away from well control. This rock-based turbidite interpretation provides an alternative to the current alluvial channel/crevasse splay/floodplain lake model for reservoir deposition and as such presents a new exploration play. Further the reservoirs’ immediate lateral association with gas/oil-prone source rocks and seals in the clay-rich lithologies potentially provide for stratigraphic trapping in addition to the previously targeted fault-controlled structural traps.
Keywords: Australia, core, lacustrine, Otway Basin, play, sedimentology, seismic facies, turbidite.
Sharon Tiainen is a graduate of the University of Adelaide and has an Honours degree in petroleum geology and geophysics. She has over 25 years’ experience in the upstream oil and gas industry having worked in exploration, appraisal, development, and production roles. She has worked acreage in Algeria, Austria, Australia, Ecuador, Germany, India, Libya, Malaysia, Morocco, Myanmar, the Netherlands, Norway, Papua New Guinea, Pakistan, the Philippines, Romania, Tunisia, Turkey, the UAE, and the United Kingdom. In 2009 she established her own company and most recently she joined the South Australia Department for Energy and Mines and is a member of EAGE, SPE and PESA. |
Rob Kirk graduated from the University of Adelaide (BSc Hons) and the University of WA (MSc) – combining geology with geophysics. He has four decades of industry experience in seismic and sequence stratigraphy having worked with SA Oil and Gas, Occidental, BHP, and Woodside as well as 20 years consulting. He has worked some 40 basins worldwide. Rob has given public and inhouse industry courses on seismic stratigraphy for 30 years. Rob jointly won the 1991 AAPG Best Paper Award, was 1993 and 2014 PESA Distinguished Lecturer, 1994 Keynote Speaker at GCSSEPM, Houston and has had regular articles in the PESA Journal. He is a member of PESA and the AAPG. |
Dr Chris Cubitt graduated from the University of Adelaide with a PhD in clastic diagenesis and sedimentology. He has more than two decades of industry experience in reservoir and regional geology working basins worldwide. In early 2023 he joined South Australia’s Department for Energy and Mining as a Deputy Director. Chris is an author of more than 20 publications, and is a member of PESA, IAS and the EAGE. |
Tim Rady is a geophysicist with 18 years’ experience in the oil & gas industry, specialising in seismic interpretation, play analysis, prospect maturation and opportunity evaluation. He has worked for Santos, Premier Oil and Total Energies on a broad range of new ventures, exploration and development projects across Australia, SE Asia, Brazil, PNG, Bangladesh, and Norway. Tim currently consults to the E&P industry and is leading the subsurface technical aspects of entX Limited’s underground hydrogen storage project. Tim holds a BSc (Hons) in Petroleum Geophysics from the Australian School of Petroleum and an MBA from the London Business School. |
References
Beach Energy Ltd (2013) Sawpit 2 well completion report. Available at https://peps.sa.gov.au/home
Beach Energy Ltd (2014a) Jolly-1/ST1 well completion report. Available at https://peps.sa.gov.au/home
Beach Energy Ltd (2014b) Bungaloo-1 well completion report. Available at https://peps.sa.gov.au/home
Cubitt C, Kirk R, Rady T, Tiainen S (2024) Gross depositional environment mapping in the onshore South Australian Otway Basin: an example of data integration. Australian Energy Producers Journal 64, S347-S353.
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Edwards C, Rady T, Cubitt C, Kirk R, Tiainen S (2024) Petroleum Systems Analysis of the Onshore Otway Basin, South Australia. Australian Energy Producers Journal 64, S359-S364.
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Shanmugam G (2016) Submarine fans: A critical retrospective. Journal of Palaeogeography 5(2), 110-184.
| Crossref | Google Scholar |
