Petroleum systems analysis of the onshore Otway Basin, South Australia
Casey Edwards A * , Tim Rady B , Chris Cubitt C , Rob Kirk D and Sharon Tiainen CA
B
C
D
Graduating with a BSc in Geology (hons) from UNSW, Casey Edwards has over 20 years’ industry experience, including several years as a senior and principal geoscientist with ECL Australia and RPS Group, where she specialised in petroleum systems analysis for conventional and unconventional systems. In 2014 Casey started Source Geoscience Pty Ltd; projects to date have included PSA work in most Australian basins and multiple international basins, for private companies and government organisations. She is a member of PESA. |
Tim Rady is a geophysicist with 18 years’ industry experience, specialising in seismic interpretation, play analysis, & prospect maturation. He has worked for Santos, Premier Oil and TotalEnergies on a broad range of projects worldwide. 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. |
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 (SADEM) as a Deputy Director and is now currently head of the Basin Prospectivity team. Chris is an author of more than 20 publications, is a member PESA, IAS and the EAGE. |
Graduating in geology and geophysics from the University of Adelaide (BSc Hons) and the University of WA (MSc), Rob Kirk has four decades of industry experience in seismic and sequence stratigraphy, working with SA Oil & Gas, Occidental, BHP, Woodside and 20 years consulting in 40+ basins worldwide. Rob has given public and inhouse industry courses on seismic stratigraphy for 30 years, jointly won the 1991 AAPG Best Paper Award, was 1993 and 2014 PESA Distinguished Lecturer and has had regular articles in the PESA Journal. He is a member of PESA and the AAPG. |
Sharon Tiainen holds an Honours degree in petroleum geology and geophysics from the University of Adelaide and has over 25 years’ experience in the oil & gas industry, having worked in exploration, appraisal, development, and production in over 20 countries. In 2009 she established her own company and most recently she joined the South Australia Department for Energy and Mines; she is a member of EAGE, SPE and PESA. |
Abstract
An updated Petroleum Systems Model was built for the South Australian onshore Otway Basin, incorporating new seismic interpretation, seismic stratigraphy, core interpretations and a recent chemostratigraphy study. The Otway Basin is a divergent passive continental margin, with the Penola Trough the most significant hydrocarbon province discovered to date. Revision of the existing geochemistry database and seismic stratigraphy along with source rock model indicates potential good quality, liquids prone lacustrine source rocks are present in the Jurassic Casterton Formation (S0-P5) and the Early Cretaceous Basal Shale (McEachern Sand equivalent)/Lower Sawpit Shale (S1-P1/S1-P2). Gas prone source rocks are modelled in the Valanginian Upper Sawpit Shale (S1-P4/S1-P5) and Hauterivian Laira Formation (S1-P6–S1-P10). Modelling suggests liquid hydrocarbons were expelled from the Lower Sawpit Shale between 126 and 70 Ma, with the majority sourced from the Penola and Robe Troughs. Gas/condensate expulsion also took place up to 30 Ma from the Upper and Lower Sawpit Shale in the Penola and Robe Troughs. Gas is modelled to have been expelled from the Laira Formation in the Tantanoola Trough, between 100 Ma and present day.
Keywords: basin modelling, gas, gas expulsion, geochemistry, lacustrine, Otway, petroleum systems modelling, oil expulsion.
Graduating with a BSc in Geology (hons) from UNSW, Casey Edwards has over 20 years’ industry experience, including several years as a senior and principal geoscientist with ECL Australia and RPS Group, where she specialised in petroleum systems analysis for conventional and unconventional systems. In 2014 Casey started Source Geoscience Pty Ltd; projects to date have included PSA work in most Australian basins and multiple international basins, for private companies and government organisations. She is a member of PESA. |
Tim Rady is a geophysicist with 18 years’ industry experience, specialising in seismic interpretation, play analysis, & prospect maturation. He has worked for Santos, Premier Oil and TotalEnergies on a broad range of projects worldwide. 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. |
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 (SADEM) as a Deputy Director and is now currently head of the Basin Prospectivity team. Chris is an author of more than 20 publications, is a member PESA, IAS and the EAGE. |
Graduating in geology and geophysics from the University of Adelaide (BSc Hons) and the University of WA (MSc), Rob Kirk has four decades of industry experience in seismic and sequence stratigraphy, working with SA Oil & Gas, Occidental, BHP, Woodside and 20 years consulting in 40+ basins worldwide. Rob has given public and inhouse industry courses on seismic stratigraphy for 30 years, jointly won the 1991 AAPG Best Paper Award, was 1993 and 2014 PESA Distinguished Lecturer and has had regular articles in the PESA Journal. He is a member of PESA and the AAPG. |
Sharon Tiainen holds an Honours degree in petroleum geology and geophysics from the University of Adelaide and has over 25 years’ experience in the oil & gas industry, having worked in exploration, appraisal, development, and production in over 20 countries. In 2009 she established her own company and most recently she joined the South Australia Department for Energy and Mines; she is a member of EAGE, SPE and PESA. |
References
Bendall B, Forbes A, Revie D, et al. (2020) New insights into the stratigraphy of the Otway Basin. The APPEA Journal 60, 691-696.
| Crossref | Google Scholar |
Bendall B, Forbes A, Hill T (2021) Resolving lithostratigraphic complexities in the Crayfish Group, Otway Basin using chemostratigraphy. The APPEA Journal 61, 588-593.
| Crossref | Google Scholar |
Boreham CJ, Hope JM, Jackson P, et al. (2004) Gas-oil-source correlations in the Otway Basin, southern Australia. PESA Eastern Australasian Basins Symposium II, 603-627.
| Google Scholar |
Boult PJ, Lyon P, Camac B, et al. (2004) Subsurface plumbing of the Crayfish Group in the Penola Trough: Otway Basin. PESA Eastern Australasian Basins Symposium II, 483-498.
| Google Scholar |
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.
| Crossref | Google Scholar |
Edwards D, Struckmeyer HIM, Bradshaw MT, et al. (1999) Geochemical characteristics of Australia’s southern margin petroleum systems. The APPEA Journal 39, 297-321.
| Crossref | Google Scholar |
Geoscience Australia (2023) Regional Geology of the Otway Basin. Available at https://www.ga.gov.au/scientific-topics/energy/province-sedimentary-basin-geology/petroleum/acreagerelease/otway
Hill T, Bendall B, Murray A (2020) New insights into the organic geochemistry of the Otway Basin. The APPEA Journal 60, 712-717.
| Crossref | Google Scholar |
Pepper AS, Corvi PJ (1995) Simple kinetic models of petroleum formation. Part I: oil and gas generation from kerogen. Marine and Petroleum Geology 12(3), 291-319.
| Crossref | Google Scholar |
Tiainen S, Kirk R, Cubitt C, Rady T (2024) Revisiting the rocks discovers turbidites and a new exploration play in the Penola Trough, Otway Basin, South Australia. Australian Energy Producers Journal 64, S435-S440.
| Crossref | Google Scholar |
