The relationship Between the Structural Evolution and Depositional Environments in the Greater Tindilpie Area, Cooper Basin, South Australia
Brenton D. Schoemaker - 2012
Honours Degree of Bachelor of Science (Petroleum Geology and Geophysics)
Australian School of Petroleum
The University of Adelaide
This study focuses on the Greater Tindilpie area in the Cooper Basin, South Australia.
Hydrocarbons are primarily produced from Early Permian tight sand reservoirs, hosted by four-way dip closures. However, there has been successful testing of reservoirs off structure. Reservoir sands have been deposited through fluvial sedimentation. Thus, by constraining the location of fluvial channel systems through time, development of the GT area can be optimised. This study analyses 3D seismic data to assess the relationship between the structural evolution and the depositional history of the GT area.
This was achieved by interpreting a fault framework and constructing isopach maps based on interpreted horizons and unconformities. Structural highs in the GT area are controlled by underlying basement propagated reverse faults. Faults experienced inversion during the Early Permian through reactivation in a compressional stress regime. Four main uplift events followed, resulting in further fault propagation into overlying stratigraphy. As the interpreted fault framework evolved through the Permian, many faults in the GT area became dormant as strain was accommodated along the major fault system on the western flank of the Gidgealpa Ridge. To interpret the isopach maps the modern Ob River in Western Siberia was used as an analogue. This analogue reveals the spatial distribution of depositional environments which are considered responsible for deposition of the Patchawarra Formation during the Permian.
The combination of the above allows for a relationship between the structural evolution and spatial distribution of depositional environments to be determined. Reactivated reverse faults create topographic highs causing diversion or constriction of fluvial systems. Therefore, fluvial sedimentation is constrained through the Permian as a result of fault propagation. Ultimately, the interpreted isopachs combined with the fault framework is a novel way to constrain the likely distribution of fluvial channel systems which will be used to further optimise hydrocarbon development in the GT area.