The Geochemical Characteristics And Gas-Source Correlation In He-8 Members Of Sulige Region, Ordos Basin

The thesis, relying on the coopration research "The causes and controlling factors of Sulige Carboniferous-Permian gas-riched areas" raised by Exploration and Development Institute of Changqing Oilfield Company and Chengdu University of Technology, attampt to difine the distribution of gas in the Upper Paleozoic in Sulige region more clearly, then choose favorable exploring targets and expand the exploration achievement, through further exploration towards the Upper Paleozoic gas in Ordos Basin. It is necessary to study the source of gas using geochemical techniques. This means significance to sulige field.Based on the previous studies, systematic research has been conducted on the organic aboundance, the organic type and the organic maturity of He-8 members source rocks in Sulige region. Therefore, a more comprehensive acquaintance has been achieved on the basic geochemical characteristics of the source rocks. To evaluate the He 8 segment resources objectively, the foundation has been established. The results show that the He 8 segment source rocks in Sulige region have a high content of organic carbon and high maturity, most of which has entered a high maturity phase. It's organic types are II2 and III mainly, and the organic matters were mostly input by the terrestrial higher plant, which has more hydrocarbon source rocks.By comparing the carbon isotope of gas, light hydrocarbon condensate, bitumen-steroidal terpane and adsorption of light hydrocarbons in source rocks, show that the gas source Sulige Xiashihezi more complex. It's organic types are II2 and III mainly, and the organic matters were mostly input by the terrestrial higher plant, natural gas is mainly coal-type gas causes,the whole is dry gas, moisture supplement. Sulige region Xiashihezi main producing formation in the oil and gas not only from coal shale, coal, and also contribute to dark micrite, are multi-source hybrid charging. Sulige region of accumulation of natural gas has many features. Even after several tectonic uplift events, early filling of gas is still preserved.