Seismic character delineation of fluvial sandbody geometry, upper Toolachee Formation, central Patchawarra Trough, Cooper Basin, South Australia

Publication Name: The Cooper & Eromanga Basins Australia

Authors: R.J. Taylor and A.D. Thomas

Date Published: June 1989

Number of Pages: 25

Reference Type: Book Section

Abstract:

Within the Late Permian Toolachee Formation of the central Patchawarra Trough a fluvial sandstone complex of
low sinuosity can be traced by mapping a seismic anomaly. The anomaly is characterised by an additional seismic peak developed below the Toolachee Formation event. Well correlation and seismic modelling of this anomaly show that it only occurs when the thickness of a sandstone/siltstone package between the two upper
Toolachee Formation coals (C1 and C2) exceeds approximately 12 m. Where the package is thinner than 12 m, the seismic resolution is insufficient to define its distribution accurately.
The seismic anomaly, is interpreted to represent a sandbody that was deposited in a meandering fluvial system. Following successive meander belt avulsions a lenticular channel system sandbody developed. A preference for channel deposition along the axes of the anomalous zones suggests some structural control on sedimentation. The distribution of this anomaly provides not only a useful tool for predicting sand-prone fairways, but also an insight into the environment of deposition of the Toolachee Formation. Further analyses of similar anomalies in the Patchawarra Trough and in other parts of the Cooper Basin will provide greater confidence for the exploration of new plays.

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Tags: Australia. basin central character Cooper delineation fluvial formation geometry Patchawarra sandbody Seismic South Toolachee Trough upper