Thin-Layer Siliceous Dolomite Prediction Based on Post-Stack Seismic Data Mining and Optimization

Siliceous dolomite is developed at the top of the fourth member of Dengying Formation in Penglai gas field, Sichuan Province, and can be used as a good cap rock to seal oil and gas. In this study, based on post-stack seismic data mining and optimization, sensitive logging curve analysis is found to be the optimal prediction method, subdividing small layers to finely characterize thin-layer siliceous dolomite. It is found that the navigation-pyramid two-stage classification seismic data and the waveform indication simulation method based on RXO parameters have a good recognition effect on the characterization of thin-layer siliceous dolomite. Studies have shown that faults can provide ascending channels for deep silicon-rich hydrothermal fluids, resulting in the development of siliceous dolomite mostly near the fault zone. The siliceous dolomite in the upper sub-member of the fourth member of Dengying Formation in Penglai area mainly develops two sets of siliceous dolomite in the vertical direction, and the lower siliceous rock develops on a larger scale. In the lateral direction, it is mainly distributed in the JT1-PS7-P8-PS9 well area in the north, in a continuous sheet shape. In the south, the development scale of siliceous dolomite is small and distributed in the shape of a strip.