Causes and Mechanisms of the Badaowan Formation Reservoir on the Southern Slope of the Mahu Depression

The Jurassic Badaowan Formation on the southern slope of the Mahu Sag has a shallow burial depth and abundant oil and gas resources. On the basis of clarifying the basic characteristics of the reservoir, an in-depth analysis is conducted on the control of sedimentation and diagenesis on the reservoir genesis. The reservoir is mainly composed of lithic sandstone and feldspathic lithic sandstone; the types of reservoir space are mainly intergranular pores and intragranular pores, belonging to a low-porosity and ultra-low-permeability reservoir. The sedimentary environment is the underwater distributary channel of the delta front subfacies, and the distribution of sedimentary facies determines the distribution of sand bodies. Compaction is the main factor destroying primary pores. The changes in reservoir physical properties are mainly controlled by sedimentation and diagenesis. Sedimentation lays the material foundation for reservoir formation, while diagenesis plays a role in later transformation of the reservoir. The research results can provide ideas and directions for the next exploration and development of the Mahu Sag.