Multi-stage hydrocarbon accumulation and formation pressure evolution in Sinian Dengying Formation-Cambrian Longwangmiao Formation, Gaoshiti-Moxi structure, Sichuan Basin
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- 作者：Juan Wu ; Shugen Liu ; Guozhi Wang ; Yihua Zhao ; Wei Sun…
- 关键词：Sichuan Basin ; Gaoshiti ; Moxi structure ; Sinian–Cambrian ; hydrocarbon accumulation ; formation pressure ; fluid inclusion
- 刊名：Journal of Earth Science
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：27
- 期：5
- 页码：835-845
- 全文大小：2,925 KB
- 刊物主题：Earth Sciences, general; Geotechnical Engineering & Applied Earth Sciences; Biogeosciences; Geochemistry; Geology;
- 出版者：Springer Berlin Heidelberg
- ISSN：1867-111X
- 卷排序：27
文摘
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.