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论文探讨了文33块天然气中CO₂气及有机气体的成因。文33-204井CO₂含量高近80%、碳同位素值重δ13C_CO2为－9.0‰，CO₂同位素指示介于有机成因与无机成因之间，与同区块高部位CO₂含量低的其他井天然气同位素差别大，伴生的烃类气体组分与碳同位素表现为油型湿气特征。综合研究认为，文33块含二氧化碳高的文33-204、文269、文269-1的天然气中有机组分与CO₂是不同源，有机组分来源于下第三系泥岩地层，CO₂气体主要来源于石炭—二叠系的煤系地层，同区块而CO₂低的天然气，有机组分与CO₂为同源的，均来源于下第三系泥岩地层。

Geochemical Characteristics of the CO2 Gas Reservoir in Wenliu Structure in Dongpu Depression and Its Genetic Analysis

Through analyzing the geochemical characteristics of both organic and inorganic components in the natural gas with high CO2 gas content in wells Wen 33―204，Wen 269 and Wen 269―1 at Block Wen―33 in the limb of Wenliu structure in Dongpu depression and analyzing the carbon isotopic features of natural gas constituent and its associated He and Ar isotopic characteristics，the geneses of the CO2 gas and organic gases in the natural gas in Block Wen―33 are discussed in the paper by comparison with the characteristics of the natural gas samples collected from the wells Wen 13，Wen 23 and Wengu 2CO2 content in well Wen 33―204 is high up close to 87％ and δ13CCO2 is -9‰CO2 isotopic value shows that this CO2 gas is between organic genetic gas and inorganic genetic gas and is much different from the one collected from the wells located at the higher portion of the same block, in which the CO2 gas content in natural gas is lowIn well Wen 33―204，the associated hydrocarbon gas components and carbon isotope are indicated as an oil type wet gas feature，being identical with the oil type gas in well Wen 13 (E s31) and being much different from the dry coal type gas in wells Wen 23 (Es4) and Wengu 2（P2 sh）The 3He/4He ratio of the natural gas in Wenliu structure shows that it is not mantle source gas but the natural gas originated from the earth crust and its  40Ar/36Ar ritio shows also that it is related to the lacustrine mudstones of Tertiary. Through a comprehensive investigation, it is considered that the organic component in the natural gas with high CO2 content found out in wells Wen 33―204, Wen 269 and Wen 269―1 in Block Wen―33 is not consanguineous with CO2 gas in it, i.e. the former was come from the mudstone of Lower Tertiary and the latter from the coal measure strata of Permian―Carboniferous. In the same block, the organic component and CO2 gas in the natural gas with low CO2 content are consanguineous and they were come from the mudstones of Lower Tertiary.