东营凹陷沙四上亚段烃源岩排烃特征及潜力评价

Hydrocarbon-Expulsion Characters and the Potential Resource Evaluation of Hydrocarbon Source Rocks from the Upper Section of 4th Member of Shahejie Formation in Dongying Depression

东营凹陷岩性类隐蔽油气藏的勘探日趋重要,其主力烃源岩的排烃特征及资源潜力的研究亟待加强。将东营凹陷沙四上亚段烃源岩分为暗色泥岩和油页岩两套,根据排烃门限理论,利用生烃潜力法对两套烃源岩的排烃特征进行了详细分析并对其资源潜力进行了评价。沙四上亚段烃源岩的主要排烃期为明化镇组沉积时期,排烃门限深度为2600 m。两套烃源岩的总排烃量和总平均远景资源量分别为59.67×108t和25.65×108t,其中暗色泥岩的总排烃量和总平均远景资源量分别占总量的72.18%和72.2%,而油页岩仅分别占27.82%和27.80%,表明暗色泥岩的资源潜力更大。综合分析后认为,沙四上亚段为岩性油藏的主力烃源层,具有良好的资源前景。

The lithologie pool plays a more and more important role in Dongying Depression, so it is necessary to enhance study its main hydrocarbon source rocks in terms of hydrocarbon-expulsion characters and potential resource evaluation. The upper section of 4th member of Shahejie Formation includes two sets of hydrocarbon source rocks： dark mudstone and oil shale. In this paper, based on the theory of hydrocarbon- expulsion threshold, the hydrocarbon-expulsion characters and the potential resource evaluation of the upper section of 4th member of Shahejie Formation is discussed by hydrocarbon-generation potential method. The upper section of 4th member of Shahejie Formation discharged hydrocarbon mainly in the depositing stage of Minghuazheng Formation, with its hydrocarbon-expulsion threshold depth at 2 600 m. The total hydrocarbon-expulsion and the total sources are 59.67×10^8 t and 25.66 ×10^8 t,in which the dark mudstone holds more than 72.18% ,and the oil shale holds sion that the the upper section of 4th member of 27.82 %. The comprehensice analysis leads to the conclu- Shahejie Formation is the main hydrocarbon source rocks to the lithologic pools in Dongying Depression.