Fluid Inclusions Analysis Of Puguang Gas Field Reservoir, Xuanhan, Sichuan

Puguang gas field as the largest gas field of Sichuan Basin is also the biggest marine carbonate formational gas reservoir. This paper systematic researches on the characteristics of fluid inclusions in Puguang gas field and it is by means of collects previous results. The results show that:In Puguang gas field, the quantity and volume of fluid inclusions is small, and the forms are complicated and various.The inclusions is classified as three major types: aqueous inclusions, hydrocarbon- aqueous inclusions and hydrocarbon inclusions.The homogenization temperatures of saline aqueous inclusions coexisting with the hydrocarbon inclusions in the three stage calcites are 85.2～117℃, 115.5～168℃and 135～217℃, respectively.The salinity of fluid inclusions has a relatively wide range from 4.49wt% to 20.22wt%. The fluid density is 0.90~1.15g/cm3. The pressure is 156.05×105Pa ~787.5×105Pa. The gas component of fluid inclusions is dominated by CH4 and H2S, and also have a little CO2.There are three periods hydrocarbon charge: the first period took place in Early Jurassic (198～182 Ma); the second period took place in Latest Early Jurassic- Middle Jurassic (180～166 Ma); the third period took place in Late Jurassic-Early Cretaceous (162～120 Ma).The Puguang gas field is a structure-lithology reservoir which has experienced primary oil reservoir stage, gas reservoir stage and reformation and definition stage.