Prediction of permian karst reservoirs in the yuanba gas field, northern sichuan basin, China

Karst reservoir has great hydrocarbon potential, however karst prediction is inhibited by the strong lateral and vertical heterogeneity of karstification which in turn results recognition difficulty when geological geophysical methods are used isolation. Combined methods, including core observation, thin section analysis, well log interpretation, seismic attributes inversion applied to understand depositional environment, types karstification, response distribution controls over evolution model Permian Yuanba gas field, northern Sichuan Basin. The show that there four major facies recognized study area, correspond platform margin reef, carbonate platform, inter-bay slope. Karstification can be divided into 3 zones: supergene zone, seepage zone horizontal underflow among have strongest karstification. highlighted with low impedance, Poisson's ratio, high attenuation on as micro scale paleo geomorphology trend surface analysis. By comparing geomorphology, fault contents, it observed a good matching relationship these factors. dominant type epigenic karst, strongly influenced geomorphology. Fracture networks contributed but not factor formation. integration predict accuracy within large area exploration similar setting.