INFLUENCE OF DIAGENETIC MINERAL FACIES BELTS ON THE ACCUMULATION PROPERTIES OF SANDSTONE IN THE WESTERN SICHUAN DEPRESSION

The sandstone reserviors show severe heterogeneity in the Shaximiao Fr.in the central part of the Western Sichuan Depression.The accumulation properties of the reservoirs are mainly controlled by diagenetic mineral facies belts.The development of secondary porosity is indicated by the chlorite-zeolite facies belt and the kaolinite facies belt.And where the plate carbonate and quartz overgrowth diagenetic mineral facies belts are developed,the sandstone is with compact texture.