东营凹陷南斜坡地层油藏成藏规律

Reservoir forming regularity of strati-graphic oil pool in the south slope of Dongying Sag

东营凹陷南斜坡地处盆地边缘,地层圈闭成藏条件优越。分析了南斜坡地区的地层油藏成藏条件,结果表明东营凹陷发育沙四段上亚段和沙三段下亚段2套优质烃源岩,断层、不整合和输导性砂层组成了油气运移的立体通道,不整合面上下的岩性类型和不整合样式有16种组合方式,储层类型多,盖层条件优越,烃源岩排烃期与地层圈闭定型期配置良好,具备形成大型地层油藏的条件。南斜坡地区地层油藏主要分布在盆地边缘的地层超剥带,超剥带与大型鼻状构造带的组合区域是地层油藏最为富集的地区。

The south slope of Dongying Sag locates at the margin of the basin , in which the stratigraphic traps have good conditions of pool forming. The forming condition of stratigraphic hydrocarbon reservoir in the south slope of Dongying Sag was analyzed. The results show that two sets of high-quality hydrocarbon source rocks developed in Dongying sag as following: the upper Sha4 submember and the lower Sha3 submember. Faults, unconformities and sandstones make up the spatial migration passage of oil and gas. There are 16 lithology-unconformity combination types above and beneath the unconformity surface. It has the conditions of large stratigraphic oil pool forming for many types of reservoir, good cap rocks and good match between hydrocarbon expulsion period of source rocks and finalizing period of stratigraphic traps. The distribution regularity of the stratigraphic oil pools is summed up in the south slope area. The stratigraphic oil pools mainly locate in the stratigraphic onlap and denudation zone of basin margin, especially the zone which stratigraphic onlap and denudation combine with large - scale of nose structure belts.