Sandstone pinchout boundaries identification using prestack analysis: a case study in JZ oilfield, Bohai Bay Basin

摘要

Accurate pinchout boundaries definition plays a significant role in reservoir delineation and appraisal of lithologic-structural traps, currently the main prospect targets in JZ oilfield. In this study, common reflection point (CRP) gather conditioning is performed at first to enhance amplitude versus offset (AVO) attributes, then prestack simultaneous inversion combined with reservoir elastic parameters cross-plotting, finally lithological probability analysis, to obtain sandstone probability cube using joint probability density functions (Pdfs). The probability cube makes it possible to interpret the elastic volumes derived from prestack simultaneous inversion quantitatively. Reservoir pinchout boundaries definition is accomplished from two aspects, namely sandstone probability values and sandstone thickness, which serves to delineate lithologic-structural traps accurately.