Research on the Diagenetic Facies of the Upper Triassic Xujiahe Formation in the Western Sichuan Foreland Basin

Based on diagenetic analysis,the reservoir of the upper Triassic Xujiahe Formation in the Western Sichuan foreland Basin can be divided into eight types of diagenetic facies such us compaction-pressolution facies,carbonate cementation facies,lining chlorite facies,dissolution facies and fracture facies based on single factor.Then the distribution of diagenetic facies of the single factor and their origins are studied based on the analyses of the reservoir's structure,sedimentation and diagenetic background.Then the comprehensive diagenetic facies of the upper Triassic Xujiahe Formation are suggested also.It is concluded that that the compaction-fracture-siliceous cementation facies of the thrust belts and the compaction-dissolution-chlorite coating facies of foredeep zones are more favorable for hosting oil.