Kinetic modeling the effects of primary migration, diffusion and waterwashing on Upper Paleozoic coal-derived gas at the center of Ordos Basin  

作　　者：SHUAI Yanhua ZOU Yanrong PENG Ping’an 

机构地区：[1]State Key Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China

出　　处：《Chinese Science Bulletin》2004年第S1期94-100,共7页

摘　　要：Gold reactor pyrolysis system is used to model the gas formation from the Upper Paleozoic coal measures and the results show coal-derived gas characterized with δ13C1 of-33.46‰, δ13C2 of-23.1‰, dryness(C1/C1-4) 85.6%. And then, effects of the post-genetic processes on coal- derived gas are analyzed in turn: (i) About 27% coal-derived gases constituted with more methane are calculated to be lost during diffusion. The residual in reservoir are characterized with almost the same compositions as the original, which suggests faint influence by diffusion (the residual, δ13C1 of -32.78‰, δ13C2 of-23.1‰, C1/C1-4 83%); (ii) Water washing made about 8% coal-formed gases lost and their components and stable carbon isotopes are stable; (iii) In the final, it is speculated that primary migration makes much more wet gas (C2-4) leave in coal measures. The variance of gas dryness induced by this factor is estimated to be about 10%.Gold reactor pyrolysis system is used to model the gas formation from the Upper Paleozoic coal measures and the results show coal-derived gas characterized with δ13C1 of ?33.46‰, δ13C2 of ?23.1‰, dryness (C1/C1–4) 85.6%. And then, effects of the post-genetic processes on coalderived gas are analyzed in turn: (i) About 27% coal-derived gases constituted with more methane are calculated to be lost during diffusion. The residual in reservoir are characterized with almost the same compositions as the original, which suggests faint influence by diffusion (the residual, δ13C1 of ?32.78‰, δ13C2 of ?23.1‰, C1/C1-4 83%); (ii) Water washing made about 8% coal-formed gases lost and their components and stable carbon isotopes are stable; (iii) In the final, it is speculated that primary migration makes much more wet gas (C2–4) leave in coal measures. The variance of gas dryness induced by this factor is estimated to be about 10%.

关 键 词：DIFFUSION migration DRYNESS ISOTOPIC ratios ORDOS Basin Upper PALEOZOIC coal. 

分 类 号：P618.11[天文地球—矿床学]