Hydrocabon Generating Potential Analysis Of Upper Permain Linxi Formation Source Rock In The Eastern Inner Mongolia

The Linxi Formation stratum of the Upper Permian series exposed widely in the eastern Inner Mongolia region. At the same time, analysis of the geophysical data shows that the Linxi Formation is widely distributed under the covers of volcanic rocks with great thickness. In the past, upper palaeozoic erathem has always been regarded as metamorphic basement of the Cenozoic basins in northeast China, and did not get enough attention. In recent years, regional oil and gas geological research shows that most of the upper palaeozoic erathems in eastern Inner Mongolia region did not get metamorphic, but developed thick dark mud shale; they have a good prospect of shale gas exploration. As one of the important hydrocarbon generations in upper palaeozoic eratnem, the Upper Permian series in Linxi Formation did not go through regional metamorphism, but after many times of tectonic activities, some local areas of regional stratum were strongly transformed, lifted, upheaved, and the stratum thermal evolution degree was high, reaching to the gas generation stage. Compared with China’s northwest and southwest regions, northeast China’s shale gas exploration and development degree is relatively low. Therefore, the research on the initial exploration of Linxi group shale gas resources in northeast China has important practical significance.Under the support of China geological survey’s major projects of The Songliao basin and Cenozoic basin in peripheral group of oil and gas geological foundation survey, this paper takes the Mid-upper Permian series in Linxi group stratum in the eastern part of the Inner Mongolia region as the research object, using the oil and gas and geological survey method to study the Linxi group of hydrocarbon source rock distribution and geochemical characteristics in the eastern part of the Inner Mongolia region through the combination of actual measurement of main section and Route geology survey and the integration of stratum deposition and structure research results. We primarily evaluated each section of Permian mudstone shale hydrocarbon generation potential of the Mid-upper Permian series in Linxi Formation stratum in the eastern Inner Mongolia region, and sat up key profile/shallow drilling oil and gas geochemical comprehensive histogram, and briefly analyzed the reservoir performance of Permian sedimentary environment and the Linxi Formation of mud shale in eastern Inner Mongolia. We compared the existing profiles and drilling datas in advantage area of hydrocarbon source rock development and comprehensively evaluated oil and gas geological conditions.Through the above research work, we basically achieved the following results and understandings:1. Mid-upper Permian series in Linxi Formation stratum is widely and thickly distributed in the eastern Inner Mongolia region. Lacustrine silty mudstone and dark mudstone with big thickness of development are important hydrocarbon-generating horizon of Songliao outlying areas.2. Comprehensive evaluation shows that hydrocarbon source rocks in Permian system Linxi Formation abundance are of medium-good; Organic matter type is mainly II type with good material base of hydrocarbon generation; The organic matter maturity is in high-mature degree, reaching the stage of gas generation.3. The late Permian epoch in eastern Inner Mongolia region mainly developed lakeside, shore, vley, semi-deep and deep lake palaeogeographic units. They major developed in the two big plate margins, from Linxi to central China-ZaLuTeQi-baicheng area, with lakeside, shallow lake, half deep lake-deep lake in turn. Statement section of the hydrocarbon potential of hydrocarbon source rock analysis, the study area of the Midwest is a favorable area for hydrocarbon generation block.4. The Linxi Formation dark mud shale has a moderate buried depth with rock composition mainly shale. Argillaceous with lamellar structure has high brittle mineral content, which is suitable for production in the late storage. At the same time, the Linxi group has experienced multiphase tectonic transformation. It has developed rock fracture and fold. The crack not only provides a channel for shale gas migration, but also provides enough storage space for shale gas.5. Through the analysis of shale gas exploration and geological conditions as well as the overall study of the characteristics of hydrocarbon source rocks in the area, we concluded that Upper Permian series in Linxi Formation have good conditions for shale gas exploration. It is a new series of strata which is favorable for the shale gas exploration in eastern Inner Mongolia region. What is more, it is expected to make fresh progress in the Songliao periphery late Paleozoic era shale gas exploration work.