The lower bedrock of the Jurassic in the Dongping area in front of the Altun Mountain in western China has good prospects for oil and gas exploration.In recent years,good oil and gas displays have been obtained during the oil drilling in this area.In order to analyze the characteristics of the base rock reservoir in this area and provide guidance for the exploration of oil and gas reservoirs,in this study,we analyze the base rock reservoir of the block through core observation,thin section identification,scanning electron microscope,core permeability measurement,and core porosity measurement methods.The results show that the bedrock in the Dongping area mainly develops two types of rocks: magmatic rocks and metamorphic rocks.The magmatic rocks are mainly granite,gabbro and diabase,and the metamorphic rocks are mainly gneiss,schist,and slate.The storage space mainly includes three types: matrix micropores,fractures,and dissolved pores,where matrix micropores and dissolved pores are the main places for oil and gas storage.Fractures are both good migration channels and the most important storage space.The porosity of the bedrock is between 2 and 6%,with an average of 4.7%.The permeability is between 0.05 and 1.0 mD,with an average of 0.711 mD.Overall,this reservoir is a fracture-dissolution type reservoir.
展开▼
