摘要：Junggar basin is one of the most important oil and gas exploration blocks in China. Mahu sag, asthe most important hydrocarbon generation sag, is rich in oil and gas resources and has good explora- tion prospects. Taking the reservoir of lower Wuerhe formation in Madong slope belt of Mahu sag as the research object, this paper studies the reservoir char- acteristics and main controlling factors of lower Wuerhe formation on the basis of core data and log-ging data. The results show that the main rock type of lower Wuerhe formation is glutenite, and there are four types of reservoir space: primary intergranular pore, residual intergranular pore, intragranular dis- solved pore and intergranular dissolved pore. Reser- voir porosity ranges from 5.12% to 10.30%, with anaverage of7.15%, and permeability ranges from 0.01 to 100mD, with an average of0.24mD. Reservoir de- velopment in this area is mainly controlled by tec- tonism, sedimentary microfacies, diagenesis and other factors, in which sedimentation is the main controlling factor. Compaction is the main factor that destroys reservoir physical properties, and the nose convex structure formed by tectonic action is the fa- vorable area of structural reservoir. Combined with the drilling logging data and oil test and production data, the favorable area of lower Wuerhe formation in the study area is predicted, and it is pointed out that type Il, type 12 and type II are the dominant res- ervoirs. The study of reservoir characteristics and main controlling factors of lower Wuerhe formation in Madong slope belt has guiding significance for ex- ploration in the study area.
