Organic geochemistry of Upper Permian Linxi Formation source rocks in Xilin Hot-Ar Horqin Banner area, Inner Mongolia

The Upper Permian Linxi Formation in Xilin Hot-Ar Horqin Banner area has a great potential of hydrocarbon. The source rocks in the study area are mainly dark mudstone and argillites. By means of organic geochemical analysis and from the geochemical parameters (i.e., organic matter abundance, kerogen type, and thermal maturity) , the authors made a comprehensive evaluation of the hydrocarbon generation potential of the source rocks. The TOC content of upper Permian hydrocarbon source rocks of Linxi Formation is mainly distributed in the range of 0.6%~0.8%, belonging to the secondary hydrocarbon source rock type. The thickness of the hydrocarbon source rock is 1827m, and the statistical thickness of the high-quality hydrocarbon source rocks is 469.7m. Main organic matter is of type Ⅲ. It has a high degree of thermal evolution of organic matter, and most Ro data are higher than 2.0%, indicating that hydrocarbon source rocks mostly achieved high mature - over mature stage of evolution. The results show that the study area has advantageous source rock, which is capable of producing high-mature natural gas, condensate gas and unconventional energy-shale gas.