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Abstract

To solve the problems of identifying and mapping prospective structures, comprehensive analysis of 3D seismic attributes is widely used at the present stage of geological research; it was applied to assess the petroleum potential of the Jurassic rock complex in the Aral Sea offshore area of the Ustyurt region. The study integrates structural mapping on the tops of Permo-Triassic and Jurassic horizons, attribute volumes (Variance/Coherence, Sweetness, root-mean-square (RMS) amplitude, Envelope) and generalized spectral decomposition (GSD, 19-41 Hz), combined with well-log and well-test data from the Western Aral, Meros, Dengiz and Karakum areas. Variance attributes were used to delineate fault zones and flexural-block areas, whereas Sweetness and RMS amplitude made it possible to identify potential reservoir-rock intervals associated with channel sand bodies and zones of elevated porosity values. Spectral decomposition refined the interpretation of fluvial palaeochannels and associated litho-facies changes. As a result, four main types of Jurassic traps were identified: structural (anticlinal), fault-bounded (tectonically screened), litho-stratigraphic channel traps and combined structural-facies traps. Based on the integrated attribute analysis, a risk cube and a prospect map were constructed, providing a basis for planning further exploration.

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36

References

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