Shale Lithofacies and Its Effect on Reservoir Formation in Lower Permian Alkaline Lacustrine Fengcheng Formation, Junggar Basin, NW China

Lower Permian Fengcheng Formation is considered to be a high-quality alkaline lacustrine shale oil resource in the Junggar Basin, NW China. Based on core and thin section observation, X-ray diffraction, scanning electron microscope, low-pressure N 2 adsorption, high-pressure mercury intrusion porosimetry, different lithofacies, pore structures were examined. According mineral composition, shales well My 1 are divided into five types: dolomitic mudstone, calcareous siliceous tuffaceous argillaceous each of which shows its structure distribution. Intragranular pores, inter-crystalline pores associated with clays pyrites, dissolution microfractures commonly observed. There three segments including <50 nm, 50 nm-4 μm, >4 μm. Clay minerals mainly contribute mesopores, especially mudstones. The carbonate feldspars significant for macropores predominantly mudstones mudstones, respectively. Micron-scale laminae dominate Therefore, lamination, proposed favored lithofacies great exploration potential Mahu Sag.