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济阳坳陷无机成因ＣＯ２气藏多沿断裂呈带状分布，且与新生代玄武岩在空间分布上关系密切．它具有高的ＣＯ２含量（６４．５５％～９９．９６％，平均为８８．１７％）和高的δ１３ＣＣＯ２值（－７．５４‰～－３．３５‰，平均为－５．０３‰），４０Ａｒ／３６Ａｒ（３１８～３０００，平均为１３５５）和３Ｈｅ／４Ｈｅ（４．６８×１０－６～３．５５×１０－６，平均为４．０１×１０－６）．这些特征表明，气藏中ＣＯ２为深部地幔来源ＣＯ２和地壳来源ＣＯ２按一定比例混合的产物．研究区内前第三系碳酸盐岩石的ＣＯ２含量及其δ１３Ｃ值的降低进一步表明，地壳来源ＣＯ２主要由碳酸盐岩石的脱碳反应形成．
The inorganic gas accumulation in the Jiyang Depression is characterized by zonal distribution along the faults and closely related to the spatial distribution of Cenozoic basalts. It has a high CO2 content (64.55% ~ 99.96%, an average of 88.17%) and a high δ13CCO2 value (-7.54 ‰ ~ -3.35 ‰, an average of -5.03 ‰) , 40Ar / 36Ar (318 ~ 3000, averaging 1355) and 3He / 4He (4.68 × 10-6 ~ 3.55 × 10-6, averaging 4.01 × 10-6). These characteristics indicate that CO2 in the gas reservoir is a product of a certain percentage of mixed CO2 from the deep mantle and CO2 from the crust. The CO2 content of pre-Tertiary carbonate rocks in the study area and the decrease of δ13C values further indicate that the crustal-derived CO2 is mainly formed by the decarbonization of carbonate rocks.