摘要
煤系地层中往往包含了源内成藏、调整成藏等多种类型油气藏,特别是在经历多期构造活动的盆地中,煤系地层油气成藏类型多、成藏机制复杂。为揭示深部煤系地层油气成藏机制,以渤海湾盆地黄骅坳陷古生界含油气系统为例,从区域构造演化史出发,通过岩心观察、煤系烃源岩地球化学测试、镜下薄片观察、包裹体测试及典型油气藏剖面解析等多种手段,结合地层埋藏史和热史,明确了煤系地层油气成藏机制,建立了成藏模式。研究结果表明:黄骅坳陷古生界含油气系统存在源下、源内、源上3种成藏组合;区域构造演化控制了烃源岩早、晚2次生烃过程,呈现“早油晚气”的生烃特征;油气2期成藏,第一期成藏发生于中白垩世,低熟原油和少量天然气主要储集于粒间孔及溶蚀孔隙中,晚白垩世的构造抬升使古油藏遭受破坏。第二期成藏发生于古近纪中期至今,大量天然气和高熟原油主要储集于溶蚀孔隙和构造裂缝中;烃源岩成熟演化、储层改造及构造活动共同控制了黄骅坳陷煤系油气成藏。基于上述认识,提出煤系油气“中转站”成藏模式,即油气优先在源内或近源储集体中聚集,后期由于构造活动改造,油气由“中转站”向其他油气低势区调整。
There are many types of hydrocarbon accumulation in coal measure strata,such as intra-source accumulation and adjusted accumulation.Particularly in basins that had experienced multi-stage tectonic activities,there are many types of hydrocarbon accumulation and its accumulation mechanism is complex.In order to reveal the mechanism of hydrocarbon accumulation in deep reservoirs,taking the Paleozoic petroleum system in Huanghua Depression of Bohai Bay Basin as an example,based on the regional tectonic evolution,by means of core observation,geochemistry testing of coal measure source rock,thin section observation,fluid inclusions testing and profile analysis of typical reservoirs,combined with the burial and thermal history of strata,the mechanism of hydrocarbon accumulation in coal measures is defined and the accumulation model was established.The results show that there are three types of source-reservoir-cap assemblages in Paleozoic petroleum system in Huanghua Depression:Under-source,intra-source and above-source assemblages.Regional tectonic evolution controlled the hydrocarbon generation process of source rocks,showing the hydrocarbon generation characteristics of“oil in the early stage and gas in the late stage”.There were two stages of hydrocarbon accumulation,the first accumulation stage occurred in the Middle Cretaceous,and the low-maturity oil and a small amount of natural gas were mainly stored in intergranular pores and dissolution pores.The tectonic uplift in the Late Cretaceous caused the destruction of the ancient reservoir.The second accumulation stage occurred in the Middle Paleogene to the present.A large amount of natural gas and high maturity oil were mainly stored in dissolution pores and structural fractures.The maturation of source rocks,reservoir reformation and tectonic activities jointly controlled the hydrocarbon accumulation in Huanghua Depression.Based on the above understanding,the hydrocarbon accumulation model of“oil and gas transfer station”in coal measures is put forward,tha
作者
杨润泽
刘海涛
李宏军
赵长毅
李传明
YANG Runze;LIU Haitao;LI Hongjun;ZHAO Changyi;LI Chuanming(Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;PetroChina Dagang Oilfield Company,Tianjin 300280,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2022年第7期1074-1090,共17页
Natural Gas Geoscience
基金
中国石油勘探生产分公司前期项目“渤海湾盆地新层系新领域研究与有利区带评价”(编号:kt2021-06-02)
中国石油科技部前瞻性项目“潜山内幕及复杂断块油气藏勘探评价技术研究”(编号:2021DJ0701)联合资助
关键词
煤系油气
生烃史
成藏组合
成藏机制
调整成藏
黄骅坳陷
Coal measure derived oil and gas
Hydrocarbon generation history
Accumulation assemblage
Accumulation mechanism
Accumulation adjustment
Huanghua Depression
