RESERVOIR CHARACTERISTICS AND MAIN CONTROLLING FACTORS OF THE XUJIAHE FORMATION IN NORTHEASTERN SICHUAN BASIN

Exploration and research show that there has favorable exploration potential in Xujiahe Formation ofnortheastern Sichuan Basin,particularly in Yuanba shallow areas,and reservoir is the key factor for gas exploration.Reservoir is the key factor of gasfield distribution in Xujiahe formation of northeastern Sichuan Basin.Based onthe study on petrologic,physical characteristics,pore types and diagenetic characteristics of the Xujiahe Formationsandstone reservoirs and their relationship,we conclude that sedimentary facies are the key factors to control the developmentof high quality reservoir.Diagenesis and tectonic fractures have an important impact on the developmentof sandstone reservoir,and the second stage of Xujiahe formation in the northeast of Yuanban area is the primarytarget for exploration where sandstone reservoir in the shallow of large-type of pores.