The enrichment law of tight sandstone gas in member 2 of Xujiahe in Yingshan gas field, Sichuan Basin

Abstract

The enrichment law of desserts in Xujiahe formation of Sichuan Basin has become the core problem of tight sandstone gas reservoir. In view of this problem, taking the member 2 of Xujiahe Formation in Yingshan area of Sichuan Basin as an example, the author analyzes the main factors of enrichment of natural gas through the analysis of the basic geological features of sedimentary environment, reservoir, hydrocarbon source, structure and reservoir formation, and then discusses enrichment mode of natural gas. The results show that the reservoir forming conditions of member 2 in Yingshan area are superior, and the widely covered source rocks are developed, and the source rocks have good hydrocarbon generation potential. The sand bodies in the delta front with thick layers are deposited in member 2 of Xujiahe, which is distributed in large area, which lays the foundation for the development of high-quality reservoirs. The reservoir space types are various, mainly mainly including primary intergranular pores, dissolution pores and micro fractures, and the reservoir has good physical properties. The accumulation of natural gas in Yingshan structure is the result of coupling of the following factors: the development of high-quality reservoir controls the distribution of natural gas; the structural background is conducive to the enrichment of natural gas; the good matching relationship between faults and traps controls the differential accumulation of natural gas in the reservoir.