An Applicable Approach of Stratigraphy-Supervised Seismic Inversion: A Case Study of Ngrayong Formation, East Java Basin

Abstract

Summary As a hydrocarbon prone formation in East Java Basin, Ngrayong Formation is a product of various depositional environments with a number of sedimentary progressions. Stratigraphical features are well-pronounced based on the seismic datasets revealing the depositional sequences of the Ngrayong Units. Seismic stratigraphy interprets each system-tracts are belonging to the transgressive-regressive sequences of Ngrayong Units which quite correlate with the well-data sequence stratigraphy. Well-data sequence stratigraphy exposes a relatively thick highstand system-tract towards transgressive system-tract on the top of Ngrayong Formation. Seismic inversion model is supervised by the system-tract boundaries to represent the stratigraphical features towards the development of the initial P-Impedance model. The process resulting in the final P-Impedance model with a greatly disseminated P-Impedance distribution within the distinctive depositional sequences. Clinoform geometries of Ngrayong Formation are clearly defined whereas conventional inversion framework lack of. The approach between seismic stratigraphy and seismic inversion analysis are a valuable aid to greatly expose the interesting intra-formation features that caused by the high variability of depositional settings.