Multi-Stage Hydrocarbon Accumulation and Formation Pressure Evolution in Sinian Dengying FormationCambrian Longwangmiao Formation, Gaoshiti-Moxi Structure, Sichuan Basin  

作　　者：Juan Wu Shugen Liu Guozhi Wang Yihua Zhao Wei Sun Jinming Song Yanhong Tian Juan Wu Shugen Liu. Guozhi Wang Yihua Zhao Wei Sun Jinming Song Yanhong Tian(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology;Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences;Chuanzhong Division of Southwest Oil & Gasfield Company,Petro China)

机构地区：[1]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology [2]Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences [3]Chuanzhong Division of Southwest Oil & Gasfield Company,Petro China

出　　处：《Journal of Earth Science》2016年第5期835-845,共11页地球科学学刊（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.41502134);the 973 Program of China(No.2012CB214805);the China Postdoctoral Science Foundation(No.2014M552327);the research grant from the Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences(No.TPR-2014-02)

摘　　要：Sichuan Basin is a typical superimposed basin, which experienced multi-phase tectonic movements, meanwhile Sinian–Cambrian underwent complex hydrocarbon accumulation processes, causing exploration difficulties in the past 60 years. Based on the microscopic evidence of fluid inclusions, combined with basin-modelling, this paper determines stages and time of hydrocarbon accumulation, reconstructs evolution of formation pressure and dynamic processes of hydrocarbon accumulation in Sinian Dengying Formation-Cambrian Longwangmiao Formation of Gaoshiti-Moxi structure. Three stages of inclusions are detected, including a stage of yellow-yellowgreen fluorescent oil inclusions, a stage of blue fluorescent oil-gas inclusions and a stage of non-fluorescent gas inclusions, reflecting the study area has experienced a series of complex hydrocarbon accumulation processes, such as formation of paleo-oil reservoirs, cracking of crude oil, formation of paleo-gas reservoirs and adjustment to present gas reservoirs, which occurred during 219–188, 192–146 and 168–0 Ma respectively. During the period of crude oil cracking, Dengying Formation-Longwangmiao Formation showed weak overpressure to overpressure characteristics, then after adjustment of paleo-gas reservoirs to present gas reservoirs, the pressure in Dengying Formation changed into overpressure but finally reduced to normal pressure system. However, due to excellent preservation conditions, the overpressure strength in Longwangmiao Formation only slightly decreased and was still kept to this day.Sichuan Basin is a typical superimposed basin, which experienced multi-phase tectonic movements, meanwhile Sinian–Cambrian underwent complex hydrocarbon accumulation processes, causing exploration difficulties in the past 60 years. Based on the microscopic evidence of fluid inclusions, combined with basin-modelling, this paper determines stages and time of hydrocarbon accumulation, reconstructs evolution of formation pressure and dynamic processes of hydrocarbon accumulation in Sinian Dengying Formation-Cambrian Longwangmiao Formation of Gaoshiti-Moxi structure. Three stages of inclusions are detected, including a stage of yellow-yellowgreen fluorescent oil inclusions, a stage of blue fluorescent oil-gas inclusions and a stage of non-fluorescent gas inclusions, reflecting the study area has experienced a series of complex hydrocarbon accumulation processes, such as formation of paleo-oil reservoirs, cracking of crude oil, formation of paleo-gas reservoirs and adjustment to present gas reservoirs, which occurred during 219–188, 192–146 and 168–0 Ma respectively. During the period of crude oil cracking, Dengying Formation-Longwangmiao Formation showed weak overpressure to overpressure characteristics, then after adjustment of paleo-gas reservoirs to present gas reservoirs, the pressure in Dengying Formation changed into overpressure but finally reduced to normal pressure system. However, due to excellent preservation conditions, the overpressure strength in Longwangmiao Formation only slightly decreased and was still kept to this day.

关 键 词：Sichuan Basin Gaoshiti-Moxi structure Sinian-Cambrian hydrocarbon accumulation formation pressure fluid inclusion. 

分 类 号：P618.13[天文地球—矿床学]