渤海湾盆地东营凹陷地层油气藏成藏阶段分析

随着渤海湾盆地东营凹陷勘探程度的逐步深入,地层油气藏在勘探中的地位不断提升,而成藏阶段的确定和划分对于地层油气藏成藏机理深入研究和成藏模式总结具有重要意义。在同源情况下,通过对东营凹陷不同区带不同类型油藏原油与烃源区源岩成熟度的对比分析,认为该区地层油气藏油气成熟度高,相对成藏时间晚;而次级构造带不同类型油藏有机包裹体均一温度统计分析表明,地层油气藏成藏时间主要在馆陶组沉积末期—明化镇组沉积时期。在综合考虑东营凹陷成藏地质要素历史演化的基础上,探讨并明确了与盆地构造—充填史相对应的地层油气藏成藏阶段模式,将其划分为多幕断陷期成藏准备、坳陷早期成藏高峰和坳陷后期油气保存等3个阶段。 

Accumulation stages of stratigraphic reservoirs in the Dongying Sag of the Bohai Bay Basin

The exploration degree in the Dongying Sag of the Bohai Bay Basin is gradually developing.The exploration position of stratigraphic reservoirs is continuously advancing.Comparative analysis of maturity of various crude oil and hydrocarbon source rocks showed that the maturity of stratigraphic reservoirs was high and the hydrocarbon accumulation dating was late.According to analysising the homogenization temperature of fluid inclusions of various oil reservoirs at the sub-structural belt,the hydrocarbon accumulation dating of stratigraphic reservoirs is from the final sedimentation period of the Guantao Formation to the sedimentation period of the Minghuazhen Formation.On the base of the evolution of reservoiring factors in the Dongying Sag,a stratigraphic reservoirs accumulating model was established,which correspond with tectonic history and filling history of basin,moreover it was divided into three stages: accumulation preparation stage,accumulation main stage and hydrocarbon preservation stage.