Identification of Structural Hydrocarbon Traps in the Amadeus
Basin
Supervisors
Research Affiliations
Degree Type/Name
Pre-requisites
Student Support
Collaboration
Prof Mike Dentith, A/Prof Annette George and Prof Peter Cawood
Tectonics Special Research Centre
Ph.D, M.Sc or Honours - Geology, Earth Science, Petroleum
Geoscience
Degree in Geology or Geophysics or other kinds Geoscience
degree. For Honours, units involving tectonics, basin analysis
and magnetic data
The student undertaking this project is eligible for financial
support provided by the UWA Geoscience Foundation.
This project is supported by Central Petroleum.
Skills
This research project provides the opportunities for research students to obtain skills and
experience in the enhancement and interpretation geophysical data an its integration with
geological information, skills highly regarded in resource exploration companies, as well as
forming a firm basis for a research or academic career.
Project Description
The Amadeus Basin, one of the major basins of central Australia, is the least explored
onshore petroleum-bearing basin with proven reserves in Australia. It is located in the
southern part of the Northern Territory and extends westward into Western Australia (Fig. 1).
The Amadeus Basin comprises rocks recording nearly 500 million years of Earth history
ranging from the latest part of the Precambrian into the Mid-Paleozoic (~800 to 300 Ma;
Lindsay et al., 2005). The sedimentary fill in the basin is at least 10 km thick. The Basin has
a complicated depositional history and structural complexity caused by the upward movement
of salt bodies during burial compaction and subsequent phases of tectonic deformation (e.g.
Lindsay & Korsch, 1991; Shaw et al., 1991; Haines et al. 2001; Dyson & Marshall, 2005);
Figure 1
Map of Amadeus Basin showing location, main features and wells.
The Amadeus Basin hosts two producing petroleum fields (Fig.1), both fields are in structural
traps. Mereenie contains considerable reserves of oil and gas and Palm Valley has gas.
Reservoirs not only contain natural gas (methane) but also helium.
High quality modern basin-wide aeromagnetic data have been flown by the Northern Territory
Geological Survey (NTGS). A preliminary appraisal of the basin-wide aeromagnetic dataset
acquired by the NTGS shows that there are responses which are consistent with potential
hydrocarbon trap structures. Initial analysis of the aeromagnetic data shows that most basin-
fill responses are caused by tabular sources, which suggests stratigraphically controlled
variations in magnetism are responsible for the observed variations in magnetic intensity.
Gravity data are also available, most are in the public domain, and additional proprietary data
will be made available for the proposed research project. In the Amadeus Basin it is
necessary to ascertain how they can be most effectively used to derive structural information
about the basin fill, and hence the presence of potential hydrocarbon traps. This will be
based on texture-based processing of these data (Fig.2, Dentith et al., 2000), petrophysical
data, all available seismic data and modeling of magnetic and gravity responses.
The ‘Noddy’ geology-geophysical modeling package will be used to understand the geological
evolution of particular areas (Jessell et al., 1993). This package allows the user to
progressively deform (fold, fault, intrude) a geological model with the intention of reproducing
the observed cross-sectional and/or geological map patterns. Importantly, the package has
the capability to calculate the gravity and magnetic responses of the model at any stage in its
development. Seismic data will also modeled, using in-house software.
An innovative aspect of the proposed research is an investigation of whether hydrocarbonbearing structures have particular geophysical and remote-sensing responses related to
seepage. Magnetic anomalies of this kind have been postulated in areas outside Australia
but there are no reported studies from this country. The origin of these anomalies is
controversial (Liu et al., 2004 and references therein). The most favoured interpretation is
that secondary magnetic minerals are created in the rocks overlying the field due to
hydrocarbon leakage.
BEFORE
AFTER
Figure 2.
Examples of results of novel techniques currently being developed at UWA to
enhance the weak magnetic responses from features in sedimentary basins. The two
datasets are from geological terrains comparable to the Amadeus Basin. The images on the
left are TMI. Those on the right are the equivalent data after enhancement.
Recommended Reading
Dentith, M.C., Cowan, D.R. and Tompkins, L.A., 2000. Enhancement of subtle features in
aeromagnetic data. Exploration Geophysics 31, 104-108.
Dyson, I.A. and Marshall, T.R., 2005. The influence of salt tectonics on Neoproterozoic to
early Palaeozoic sedimentation, Amadeus Basin. Central Australian Basins Symposium
Handbook, 25-27.
Haines, P.W., Hand, M. and Sandiford, M. 2001. Palaeozoic synorogenic sedimentation in
central and northern Australia: a review of distribution and timing with implications for the
evolution of intracontinental orogens. Australian Journal of Earth Sciences, 48, 911-928.
Jessell, M.W., Valenta, R.K., Jung, G., Cull, J.P. and Geiro, A., 1993. Structural geophysics.
Exploration Geophysics 24, 599-602.
Lindsay, J.F. and Korsch, R.J., 1991. The evolution of the Amadeus Basin, central Australia.
In, Korsch, R.J. and Kennard, J.M., (Editors), Geological and Geophysical Studies in the
Amadeus Basin, Central Australia, BMR Bulletin 236, 7-32.
Lindsay, J.F., Kruse, P.D., and five others, 2005. The Neoproterozoic–Cambrian record in
Australia: a stable isotope study. Precambrian Research 143, 113-133.
Liu, Q., Chan, L., Liu, G., Li, H., Wang, F., Zhang, S., Xia, X. and Cheng, T., 2004.
Relationship between magnetic anomalies and hydrocarbon microseepage above the
Jingbian gas field, Ordos Basin, China. AAPG Bulletin 88, 241-251.
Shaw, R.D., Korsch, R.J., Wright, C. and Goleby, B.R., 1991. Seismic interpretation and
thrust tectonics of the Amadeus Basin, central Australia, along the MBR regional seismic line.
BMR Bulletin 236, 385-408.