Mechanism of diapirism and episodic fluid injections in the Yinggehai Basin  

作　　者：郝芳 李思田 龚再升 杨甲明 

机构地区：[1]Department of Geoscience, Petroleum University, Beijing 102200, China [2]Basin Research Institute, China University of Geosciences, Wuhan 430074, China [3]China National Offshore Oil Corporation, Beijing 100027, China

出　　处：《Science China Earth Sciences》2002年第2期151-159,共9页中国科学（地球科学英文版）

基　　金：This project was supported by the National Natural Science Foundation of China (Grant No.40125008) and 973 Project (Grant No. 1999043309).

摘　　要：The diapirism in the Yinggehai Basin is a combined result of strong overpressure caused by rapid sedimentation of fine-grain sediments and the tensile stress field resulting from right-lateral slip of the boundary-fault. The diapirism showed multiple-stage, episodic nature, and caused intermittent counter-direction onlaps and changes in the thickness of strata. The shallow gas reservoirs in the diapir structural zone displayed obvious inter-reservoir compositional heterogeneities, and their filling history could be divided into 4 stages, with gases injected during different stages having different hydrocarbon gas, CO2 and N2 contents and different stable isotope compositions. The multiple-episode, intermittent activities of the diapirs, multiple-stage, non-continuous injections of fluids, and the transient thermal effect of fluid flow as well as the strong migration fractionation reflected episodic fluid injection and natural gas accumulation.The diapirism in the Yinggehai Basin is a combined result of strong overpressure caused by rapid sedimentation of fine-grain sediments and the tensile stress field resulting from right-lateral slip of the boundary-fault. The diapirism showed multiple-stage, episodic nature, and caused intermittent counter-direction onlaps and changes in the thickness of strata. The shallow gas reservoirs in the diapir structural zone displayed obvious inter-reservoir compositional heterogeneities, and their filling history could be divided into 4 stages, with gases injected during different stages having different hydrocarbon gas, CO2 and N2 contents and different stable isotope compositions. The multiple-episode, intermittent activities of the diapirs, multiple-stage, non-continuous injections of fluids, and the transient thermal effect of fluid flow as well as the strong migration fractionation reflected episodic fluid injection and natural gas accumulation.

关 键 词：Yinggehai Basin OVERPRESSURE DIAPIRISM fluid heterogeneity injection history episodic accumulation 

分 类 号：P618.13[天文地球—矿床学]