Reservoir Characteristics and Controlling Factors of Oil Content in Hybrid Sedimentary Rocks of the Lucaogou Formation, Western Jimusar Sag, Junggar Basin

Hybrid sedimentary rocks (HSR) are a major reservoir type in unconventional oil exploration. The characteristics and controlling factors of the content HSR not clear, restricting understanding storage mechanism sweet spots within HSR. Lucaogou Formation western Jimusar Sag is taken as case study. Starting with classification lithofacies system, differences microscopic pore structure, reservoirs revealed. results show that seven recognized based on mineral composition, organic matter characteristics, exhibiting rapid vertical horizontal changes affected by environment. Layered mudstone shallow lake mud massive dolomitic flats have worst physical properties properties. However, they do high contents main source Formation. argillaceous siltstone dolomite interbed frequently. Although their moderate, “source-reservoir integrated” can be formed, due to adjacent rock. Massive siltstone, silty developed middle Formation, highest proportion mesopores macropores, which indicative good When these filled crude generated from at top bottom formation, “source adjacent” formed. also controlled structure specific surface area. macropores positively correlated content. samples very low, when area exceeds 2 m /g. This manuscript provides geological basis for evaluating establishing reasonable interpretation models spots.