Development of Diapirs and Accumulation of Natural Gases in Yinggehai Basin  

作　　者：Gong Zaisheng China National Offshore Oil Corporation, Beijing 100029 Yang Jiaming Institute of Petroleum Exploration and Development, China National Offshore Oil Corporation, Gaobeidian 074010 Hu Jianwu Hao Fang Faculty of Earth Resources, 

出　　处：《Journal of China University of Geosciences》2001年第2期127-131,共5页中国地质大学学报（英文版）

基　　金：ThepaperissupportedbyNationalNaturalScienceFoundationofChina(No .49732 0 0 5) .

摘　　要：Overpressure developed throughout most of the Yinggehai basin. The burial depth to top overpressure varied from about 1 600 m to 4 500 m, with the shallowest top overpressure occurring in the depocenter. The main cause of the overpressure was disequilibrium compaction resulting from rapid sedimentation of fine grained sediments. The overpressure was strengthened by the retention of fluids including gases due to lack of faults before diapir development. The diapirism in the Yinggehai basin was a combined result of the strong overpressure and the tensile stress field caused by the right lateral slip of the boundary fault. The diapirism, a product of the movement of overpressured fluids and plastic shales, shaped the vertical conduits from source to traps that would be absent without overpressured fluid release. Natural gas accumulation in traps in the diapir structure zones was also intermittent, which can be inferred from the inter reservoir compositional heterogeneity, transient thermal effect of fluid flow and migration fractionation.Overpressure developed throughout most of the Yinggehai basin. The burial depth to top overpressure varied from about 1 600 m to 4 500 m, with the shallowest top overpressure occurring in the depocenter. The main cause of the overpressure was disequilibrium compaction resulting from rapid sedimentation of fine grained sediments. The overpressure was strengthened by the retention of fluids including gases due to lack of faults before diapir development. The diapirism in the Yinggehai basin was a combined result of the strong overpressure and the tensile stress field caused by the right lateral slip of the boundary fault. The diapirism, a product of the movement of overpressured fluids and plastic shales, shaped the vertical conduits from source to traps that would be absent without overpressured fluid release. Natural gas accumulation in traps in the diapir structure zones was also intermittent, which can be inferred from the inter reservoir compositional heterogeneity, transient thermal effect of fluid flow and migration fractionation.

关 键 词：Yinggehai basin OVERPRESSURE DIAPIRISM episodic natural gas accumulation. 

分 类 号：P618.13[天文地球—矿床学]