In the view of water-rock interaction

the evolution process of the reservoir spaces.of natural gas in the Permian Yangxin Sense of Weiyuan structure

Sichuan Province karst fissure-cave system could be divided into depositional

emergence and burial stages.Abundant karst effected evidences found during the study show that at least three types ofkarst such as depositional karst

emergence karst and burial karst developed in they&ngxin Series. It is proposed by the authors that the present karst fissure-cave system ofthis area is the result of superposition of karst and the reservoirs are mainly karst controlled ones.