Australian Governement branding Australian Government branding

Northern Sorell Basin

Bids close 21 April 2016

  • Under-explored Mesozoic–Cenozoic basin
  • Overlies large area of the frontier Sandy Cape Sub-basin, a depocentre containing up to 6 km of sediment
  • Potential presence of petroleum systems proven to be productive in adjacent basin
  • Potential good quality reservoirs and seals, oil- and gas-prone source rocks and active petroleum systems
  • Shallow to ultra-deep water depths, 100–3200 m
  • Adjacent to recently awarded permit
  • Adjacent to Release Area T15-2 in the Otway Basin
  • Special Notices apply, refer to Guidance Notes

Release Area T15-3 is located within the northern Sorell Basin, covering a large portion of the Sandy Cape Sub-basin, offshore of western Tasmania (Figure 1). It covers an area 5741 km2 consisting of 88 graticular blocks located along the continental shelf and slope, in water depths ranging from approximately 100 m to 3200 m. The area is adjacent to the Otway Basin, a well established gas-producing basin and is considered to have experienced a similar geologic history and have contiguous stratigraphy (Figure 2). Petroleum exploration permit T/49P (Figure 1), granted in 2013, adjoins T15-3 on the eastern half of its northern boundary.

Although the area is considered frontier, there are several factors suggesting that active petroleum systems may exist within the basin. These include the presence of a Cretaceous basin fill up to 6000 m thick (Figure 3) which is interpreted to contain organic-rich coaly, deltaic and marine facies that are mature for hydrocarbon generation in much of the basin, and traces of free oil and minor gas indications in a well to the south (Cape Sorell 1).

Figure 4 shows the existing data coverage of the region which includes numerous, open file 2D seismic surveys. Figure 4 also gives the locations of petroleum exploration wells near to the release area, including Jarver 1 (2008) in the southern part of the Sandy Cape Sub-basin and Clam 1 in the adjacent King Island Sub-basin. The area also has a good aeromagnetic data coverage.

Petroleum systems elements

Northern Sorell Basin

Potential Sources
  • Lower Cretaceous fluvio–lacustrine, coaly rocks equivalent to the Otway Group of the Otway Basin
  • Upper Cretaceous fluvio-deltaic to marine sediments equivalent to the Sherbrook Group of the Otway Basin (potential to generate both oil and gas).
Potential Reservoirs
  • Upper Cretaceous sandstones equivalent to the Waare Formation, Flaxman Formation and the “Thylacine Sandstone Member” at the base of the Belfast Mudstone that are present in the Otway Basin
  • Upper Cretaceous sandstones equivalent to the Paaratte Formation of the Otway Basin
  • Paleocene and Eocene sandstones equivalent to those of the Wangerrip Group of the Otway Basin
  • Eocene and Oligocene sandstones equivalent to those of the Nirranda Group in the Otway Basin
  • Oligocene and Miocene sandstones equivalent to those of the Heytesbury Group of the Otway Basin
Potential Seals Regional Seals
  • A thick Upper Cretaceous claystone, siltstone and sandstone unit overlying the basal Upper Cretaceous sandstones
  • Oligocene and Miocene marls and fine-grained limestone equivalent to those within the Heytesbury Group of the Otway Basin

Intra-formational Seals

  • Upper Cretaceous rocks within the sequence equivalent to the Paaratte Formation and the Belfast Mudstone of the Otway Basin
Potential Traps
  • Structural traps (high-side fault traps and faulted anticlines) in the Waarre Formation and Sherbrook Groups
  • Paleocene–early Eocene canyon-related stratigraphic traps

Infrastructure and markets

No infrastructure exists, or is planned, within the Sorell Basin, as the basin is frontier. The nearest gas pipelines in operation are located approximately 120 km to the north–northwest, servicing the Thylacine and Geographe gas fields in the Otway Basin and 185 km to the northeast in the Bass Basin. The Tasmanian Gas Pipeline that delivers gas from the Gippsland Basin across Bass Strait to the northern part of Tasmania is also nearby at Port Latta, approximately 115 km to the east of the release area.

Critical risks

As this is a frontier area, risks derive from the lack of infrastructure and the limited exploration thus far, especially in the more distal and thicker parts of the basin—namely, the distribution and nature of source, reservoir and seal facies and thus lack of understanding of the petroleum systems, migration pathways and play types in the region. The potential size of petroleum accumulations and their preservation as a result of latest Cretaceous–Paleocene structural reactivation, could also be an issue.

Data sets

Wells Data and Seismic Survey listings for the northern Sorell Basin are available on the Supporting Information page.

Geoscience Australia products

Regional geology and seismic

Stratigraphy

Search for these and other Geoscience Australia reports and products at www.ga.gov.au/search

Contact Geoscience Australia’s Sales Centre for more information or to order these reports or products, phone +61 (0)2 6249 9966, email sales@ga.gov.au

AMOCO AUSTRALIA PETROLEUM COMPANY, 1982—Cape Sorell 1. Geological Completion Report, Exploration Permit T/12P, offshore west Tasmania, Australia. Mineral Resources Tasmania Report, OR_0358A (unpublished).

BLEVIN, J.E. AND CATHRO, D.L., 2008—Australian Southern Margin Synthesis, Project GA707. Client report to Geoscience Australia by FrOG Tech Pty Ltd. https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&catno=68892

BOREHAM, C.J., BLEVIN, J.E., DUDDY, I., NEWMAN, J., LIU, K., MIDDLETON, H., MACPHAIL, M.K. AND COOK, A.C., 2002—Exploring the potential for oil generation, migration and accumulation in Cape Sorell-1, Sorell Basin, offshore West Tasmania. The APPEA Journal, 42 (1), 405–435.

CONOLLY, J. AND GALLOWAY, M.J., 1995—Hydrocarbon prospectivity of the offshore West Coast of Tasmania. Tasmanian Geological Survey, Record, 1995/04 (unpublished).

ESSO EXPLORATION AND PRODUCTION AUSTRALIA INCORPORATED, 1969—Clam 1 well completion report. Mineral Resources Tasmania Report, OR_0335 (unpublished).

EXON, N.F., BRINKHUIS, H., ROBERT, C.M., KENNETT, J.P., HILL, P.J. AND MACPHAIL, M.K., 2004—Tectono-sedimentary history of uppermost Cretaceous through Oligocene sequences from the Tasmanian region, a temperate Antarctic margin. In: Exon, N.F., Kennett, J.P. and Malone, M.J. (eds), The Cenozoic Southern Ocean: Tectonics, Sedimentation, and Climate Change between Australia and Antarctica. American Geophysical Union, Geophysical Monograph Series, 151, 319–344.

EXON, N.F., LEE, C.S., FELTON, E.A., HEGGIE, D., MCKIRDY, D., PENNEY, C., SHAFIK, S., SREPHENSON, A. AND WILSON, C., 1992—BMR Cruise 67: Otway Basin and west Tasmanian sampling. Bureau of Mineral Resources, Geology and Geophysics, Report, 306.

EXON, N.F., LEE, C.S., HILL, P.J. AND SHIPBOARD PARTY, 1989—Preliminary Post-cruise report: BMR Cruise 78. Rig Seismic geological and geophysical research cruise off western and southeastern Tasmania. Bureau of Mineral Resources, Geology and Geophysics, Record, 1989/12.

EXON, N.F., WHITE, T.S., MALONE, M.J., KENNETT, J.P. AND HILL, P.J., 2001b—Petroleum potential of deepwater basins around Tasmania: insights from Deep Ocean Drilling Program Leg 189. In: Hill, K.C. and Bernecker, T. (eds), 2001—Eastern Australasian Basins Symposium: A Refocused Energy Perspective for the Future. Petroleum Exploration Society of Australia, Special Publication, 49–60.

GIBSON, G. M., TOTTERDELL, J.M., MORSE, M. P., GONCHAROV, A., MITCHELL, C.H. AND STACEY, A.R., 2012—Basement structure and its influence on the pattern and geometry of continental rifting and breakup along Australia’s southern rift margin. Geoscience Australia, Record, 2012/47.

HILL, P.J. AND DE DECKKER, P., 2004—AUSCAN seafloor mapping and geological sampling survey on the Australian southern margin. Geoscience Australia, Record, 2004/04.

HILL, P.J. AND EXON, N.F., 2004—Tectonics and basin development of the offshore Tasmanian area incorporating results from Deep Ocean drilling. In: Exon, N.F., Kennett, J.P. and Malone, M.J. (eds), The Cenozoic Southern Ocean: Tectonics, Sedimentation, and Climate Change between Australia and Antarctica. American Geophysical Union, Geophysical Monograph Series, 151, 19–42.

HINZ, K. AND SHIPBOARD PARTY, 1985—Geophysical, geological and geochemical studies off West Tasmania and on the South Tasman Rise. Bundesanstalt für Geowissenschaften und Rohstoffe Cruise Report, Cruise SO36(2).

KRASSAY, A.A., CATHRO, D.L. AND RYAN, D.J., 2004—A regional tectonostratigraphic framework for the Otway Basin. In: Boult, P.J., Johns, D.R. and Lang, S.C. (eds), Eastern Australasian Basins Symposium II. Petroleum Exploration Society of Australia, Special Publication, 97–116.

LODWICK, W.R., PASSMORE, V.L., HILL, P.J., LAVERING, I.H., VUKOVIC, V. AND DAVEY, S., 1999—Sorell Basin, Tasmania, Petroleum Prospectivity Bulletin. Australian Geological Survey Organisation (AGSO), June 1999, (CD-ROM).

MARTINEZ, J.I., CHAPRONIERE, G.C.H., SHATIK, S. AND NICOLL, R.S., 1998—Sorell Basin, Biozonation and Stratigraphy, 1998, Chart 13. In: Smith, T.E., Kelman, A.P., Nicoll, R.S., Laurie, J.R. and Le Poidevin, S.R., 2013. Geoscience Australia's Basin Biozonation and Stratigraphy Chart Series. Basin Biozonation and Stratigraphy Chart Series.

MAXUS, 1993—Block T/24P West Tasmania, Australia: an exploration opportunity. Farmout brochure, Maxus Energy Corporation (unpublished).

MOORE, A.M.G., 1991—Western Tasmanian Margin seismic interpretation and mapping. Geoscience Australia, Record, 1991/070.

MOORE, A.M.G., WILLCOX, J.B., EXON, N.F. AND O’BRIEN, G.W., 1992—Continental shelf basins on the west Tasmania Margin. The APEA Journal, 32, 231–250.

MORSE, M.P., GIBSON, G.M. AND MITCHELL, C.H., 2009—Basement constraints on offshore basement architecture as determined by new aeromagnetic data acquired over Bass Strait and the western margin of Tasmania. Extended Abstract. Australian Society of Exploration Geophysicists and Petroleum Exploration Society of Australia, 20th International Geophysical Conference and Exhibition. Adelaide.

NORVICK, M.S. AND SMITH, M.A., 2001—Mapping the plate tectonic reconstruction of southern and southeastern Australia and implications for petroleum systems. The APPEA Journal, 41(1), 15–35.

O’BRIEN, G.W., TINGATE, P.R., BLEVIN, J.E., BOREHAM, C.J., MITCHELL, A., CALVER, C. AND WILLIAMS, A., 2004—Hydrocarbon generation, migration, leakage and seepage on the West Tasmanian margin. In: Boult, P.J., Johns, D.R. and Lang, S.C. (eds), Eastern Australasian Basins Symposium II. Petroleum Exploration Society of Australia, Special Publication, 163–180.

PITMAN, J., 2008—Jarver 1 Basic data Report. Santos Ltd report (unpublished).

STACEY, A.R., MITCHELL, C.H., STRUCKMEYER, H.I.M. AND TOTTERDELL, J.M., 2013—Geology and hydrocarbon prospectivity of the deepwater Otway and Sorell basins, offshore southeastern Australia. Geoscience Australia, Record, 2013/02.

TOTTERDELL, J., HALL, L., HASHIMOTO, T., OWEN, K. AND BRADSHAW, M., 2014—Petroleum geology inventory of Australia's offshore frontier basins. Geoscience Australia, Record, 2014/009.

WALKER, T.R., 2007—Deepwater and frontier exploration in Australia—historical perspectives, present environment and likely future trends. The APPEA Journal, 47(1), 13–36.

Figures

Select image to zoom.

Download All Images


 

Figure 1

 Sorell Basin-Northern Sorell Basin-figure-1 map image
Location map of the northern Sorell Basin 2015 Release Area, showing exploration wells, petroleum accumulations and the location of the seismic section in Figure 3. Release Areas shown by outline only are discussed elsewhere.
Image icon Download image (3.8 MB)

Figure 2

 Sorell Basin-Northern Sorell Basin-figure-2 map image
Stratigraphy of the Sandy Cape Sub-basin, northern Sorell Basin. The stratigraphy and hydrocarbon discoveries in the Gambier Embayment and Voluta Trough of the “deepwater Otway Basin” (based on the Otway Basin Biozonation and Stratigraphy Chart 34; Mantle et al, 2009) is also shown for reference. Geologic Time Scale after Gradstein et al (2012).
Image icon Download image (2.13 MB)

Figure 3

 Sorell Basin-Northern Sorell Basin-figure-3 map image
Seismic line ds01/126 across the northern Sorell Basin and parts of the Nelson and Inner Otway sub-basins of the adjacent Otway Basin. Interpretation by Stacey et al (2013). Location of the seismic line is shown in Figure 1.
Image icon Download image (3.24 MB)

Figure 4

 Sorell Basin-Northern Sorell Basin-figure-4 map image
Seismic and well data coverage in the vicinity of the Release Area in the northern Sorell Basin. Release Areas shown by outline only are discussed elsewhere.
Image icon Download image (4.97 MB)