Abnormal overpressure distribution and natural gas accumulation in foreland basins, Western China  

作　　者：SONG Yan XIA Xinyu HONG Feng QIN Shengfei FU Guoyou 

机构地区：[1]Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China [2]Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550002,China

出　　处：《Chinese Science Bulletin》2002年第S1期71-77,共7页

摘　　要：Abnormal overpressure occurs in the forelandbasins of Kuqa, South Junggar and West Sichuan in China.The pressure coefficients are high. Overpressure exists inwide areas and various strata. The layers of overpressurehave a very close relationship with lithology, and the area ofoverpressure is controlled by the piedmont depression. Themechanisms of overpressure formation in the Kuqa andSouth Junggar Depression include disequilibrium compac-tion and tectonic compression; the importance of these twofactors varies in different basins and in different stages of thesame basin. Different models of gas accumulation are estab-lished to explain the relationship between overpressure dis-tribution and gas pool formation, and the influence of over-pressure on the gas pools. These models include: (i) theviolent tectonic movement leads to the pool formation inoverpressure belt (Kela-2 gas field in Kuqa); (ii) the pres-sure releases at shallow part and the gas pool forms in latetime (Hutubi gas field in southern Junggar Basin); (iii)through the pressure transfer the gas migrates and accumu-lates (Xinchang gas field in Western Sichuan Basin).Abnormal overpressure occurs in the foreland basins of Kuqa, South Junggar and West Sichuan in China. The pressure coefficients are high. Overpressure exists in wide areas and various strata. The layers of overpressure have a very close relationship with lithology, and the area of overpressure is controlled by the piedmont depression. The mechanisms of overpressure formation in the Kuqa and South Junggar Depression include disequilibrium compaction and tectonic compression; the importance of these two factors varies in different basins and in different stages of the same basin. Different models of gas accumulation are established to explain the relationship between overpressure distribution and gas pool formation, and the influence of overpressure on the gas pools. These models include: (i) the violent tectonic movement leads to the pool formation in overpressure belt (Kela- 2 gas field in Kuqa); (ii) the pressure releases at shallow part and the gas pool forms in late time (Hutubi gas field in southern Junggar Basin); (iii) through the pressure transfer the gas migrates and accumulates (Xinchang gas field in Western Sichuan Basin).

关 键 词：FORELAND basin ABNORMAL pressure GENESIS natural gas accumulation. 

分 类 号：P618.13[天文地球—矿床学]