Triassic and Older Source Rock Petroleum Systems Study
Last updated:7 June 2023
Overview
The Energy Systems Branch has compiled a comprehensive inventory for Australia’s offshore frontier basins including their petroleum systems and exploration status (Totterdell et al., 2014). This inventory underpins a strategic approach to prioritizing pre-competitive basin studies. The Roebuck Basin on Australia’s offshore north-western margin was rated as moderately prospective and it is now the focus of a regional prospectivity assessment being undertaken by the North West Margin Energy Studies Section (NWMES). A key theme within this study is the occurrence and distribution of Triassic and older hydrocarbon source rocks and what this means for regional petroleum systems and play fairways. The recent oil and gas discoveries at Phoenix South 1 (2014), Roc 1 (2015-16), Roc 2 (2016), Phoenix South 2 (2016), Phoenix South 3 (2018) and Dorado 1 (2018) wells in the Bedout Sub-basin demonstrate the presence of a petroleum system in the Lower Triassic (and possibly Permian) strata. The current study aims to establish the extent of this new petroleum system, and other potential Triassic and older systems, across the central north-west margin.
This multi-disciplinary regional study’s main objectives are to:
- compile depositional models and palaeogeographic maps of the Triassic and older succession by integration of sequence stratigraphy, structural interpretation and facies mapping, and
- Assess the hydrocarbon-generative potential of potential source rocks and carry out oil and gas to source correlations to better understand petroleum systems in the region.
TR10.0 sequence boundary (basal Triassic unconformity) in TWT across the study area. Major structural features and exploration wells are labelled.
References
Totterdell, J.M., Hall, L., Hashimoto, T., Owen, K., Bradshaw, M.T., 2014. Petroleum geology inventory of Australia’s offshore frontier basins. Geoscience Australia, Record 2014/09.
Reports, datasets and presentations
Grosjean, E., Edwards, D., Rollet, N., Boreham, C., Nguyen, D., Buckler, T. 2021. Geochemical evidence for a new Triassic petroleum system in Australia - APPEA 2021 presentation. Geoscience Australia, Canberra.
Grosjean, E. 2020. Organic geochemical data release for petroleum fluids of the Roc 1 and 2 wells, Bedout Sub-basin, Australia. Record 2020/021. Geoscience Australia, Canberra.
Grosjean, E., Edwards, D.S., Hong, Z., Jinadasa, N., Sohn, J., Buckler, T., Abbott, S. 2020. Organic Geochemical Data Release for Source Rocks of the Roc 2 Well, Bedout Sub-basin, Australia. Record 2020/018. Geoscience Australia, Canberra.
Grosjean, E., Edwards, D.S., Hong, Z., Jinadasa, N. & Buckler, T., 2019. TOC and Rock-Eval pyrolysis data from the well Roc 2, Roebuck Basin, Australia. Record 2019/12. Geoscience Australia, Canberra.
Grosjean, E., Edwards, D.S., Hong, Z., Jinadasa, N., Sohn, J. & Buckler, T., 2019. Geochemical compositions of natural gases from the wells Roc 1 and Roc 2, Roebuck Basin, Australia. Record 2019/11. Geoscience Australia, Canberra.
Grosjean, E., Edwards, D.S., Sohn, J., Hong, Z., Jinadasa, N. & Buckler, T., 2019. Organic geochemical data release for Phoenix South 1 ST2 oils, Bedout Sub-basin, Australia. Record 2019/13. Geoscience Australia, Canberra.
Rollet, N., Grosjean, E., Edwards, D., Kempton, R., Nguyen, D., Abbott, S., Orlov, C., Bernardel, G., Nicholson, C. (2019). Triassic petroleum systems on the central North West Shelf – Learnings from the greater Phoenix area seismic mapping and geochemical studies. AEGC Conference Extended Abstract.
Shi, Z. and Rollet, N., (2019). Enhanced gravity and magnetic grids for Northern Australia [Digital Dataset] Geoscience Australia, Commonwealth of Australia, Canberra.
Orlov, C., Abbott, S., Bernardel, G., Nicholson, C., Rollet, N., Nguyen, D., Gunning, M. (2019). Triassic Horizon Grids, Isochron Grids, and Fault Maps, Central North West Shelf [Digital Dataset] Geoscience Australia, Commonwealth of Australia, Canberra.
Nguyen, D., Rollet, N., Grosjean E., Edwards, D., Abbott, S., Orlov, C., Bernardel, G., Nicholson, C., Kelman, A., Khider, K. and Buckler, T. (2019). The Roebuck Basin, Beagle and Barcoo Sub-basin Well Folio [Digital Dataset] Geoscience Australia, Commonwealth of Australia, Canberra.
Grosjean, E., Edwards, D.S., Hong, Z., Sohn, J., Jinadasa, N., Chen, J., (2018). Does the Phoenix South 1 oil represent an extension of the Lower Triassic petroleum system of the Perth Basin? In: Australian Organic Geochemistry Conference proceedings, 3–7 December 2018, Canberra, Australia. Abstract and presentation.
The following Destructive Analysis Reports are available from NOPIMS.
Grosjean, E., Edwards, D.S. & Hong, Z., 2018. TOC and Rock-Eval pyrolysis data from wells Phoenix South 1, Phoenix South 1 ST1 and Phoenix South 1 ST2, Roebuck Basin, Australia. Geoscience Australia. Resources Division Report 2018-001. Destructive Analysis Report DAR 1818.
Ranasinghe, S.P. & Crosdale, P.J., 2018. Organic petrology and maturation of sample suites from Phoenix 2, Phoenix 1, Phoenix South 1, Phoenix South 1 ST1 and Phoenix South 1 ST2 from Roebuck Basin – Western Australia. Report prepared for Geoscience Australia. Destructive Analysis Report DAR 1839.
Ranasinghe, S.P. & Crosdale, P.J., 2018. Organic petrology and estimated maturation of sample suites from Flinders Shoal 1, Jupiter 1, Giralia 1, Senecio 1, Woodada Deep 1, BHP Noonkanbah PND 1, Areva NC 38, Areva NC 40 Wells - Western Australia. Report prepared for Geoscience Australia. Destructive Analysis Report DAR 1840.
Mahlstedt, N. & Horsfield, B., 2018. Petroleum generation and PhaseKinetics characteristics of two Triassic source rock kerogen samples from wells Jupiter 1 and Phoenix 2, Western Australia. Report prepared for Geoscience Australia. GEOS4 Report Nr. 20181406. Destructive Analysis Report DAR 1843.
Kempton, R.H. & Wang, H., 2019. GOI™ hydrocarbon migration in Triassic and Jurassic strata of the Beagle and Roebuck basins, North West Shelf. CSIRO Open File Report EP193066, Australia. Report prepared for Geoscience Australia. Destructive Analysis Report DAR 1891.
Ranasinghe, S.P. & Crosdale, P.J., 2019. Report on source rock type, maturation levels and hydrocarbon potential of a suite of samples from Roc 2 well, Western Australia. Report prepared for Geoscience Australia. Destructive Analysis Report DAR 1892.
Mahlstedt, N. & Horsfield, B., 2019. Petroleum generation and PhaseKinetics characteristics of two source rock kerogen samples of the Caley Member from the Roc 2 well, Western Australia. Report prepared for Geoscience Australia. GEOS4 Report Nr. 20190618. Destructive Analysis Report DAR 1893.