断裂是复杂断块油气藏聚集成藏最主要的控制因素,查明断裂体系发育特征和封闭性的强弱是断块油气藏勘探开发和有利区带预测的关键。本文在对东营穹窿构造区地震资料精细解释的基础上,结合相干体和断裂活动性对断裂体系的时空发育特征进行了分析,并对主要断层的封闭性进行了评价,在此基础上探讨了断裂封闭性与油气聚集分布的关系,结果表明:东营穹窿构造的形成与孔店组、沙四段的盐、膏岩及塑性泥岩层的上拱、北界边界断层的逆牵引和后期的右旋张扭有关,多期次叠加、多方向伸展、多类型组合的断裂体系将其复杂化;不同构造层、不同部位断层封闭性的存在较大差异,Es3—Es2。亚段二级断层封闭性较好,三级断裂则较差,Es2LEd段则表现出相反的趋势;油气藏的聚集分布与断层封闭性好坏具有很好的相关性,多聚集于封闭性好的断层附近,封闭性差的油源断层很难聚集成藏。
Fracture is the most important controlling factor for fault-block reservoirs. So clarifying fault system developmentcharacteristics and its sealing properties is a key step-in fault-block reservoirs' exploration and development and favorable-zones prediction. Many methods have been used to deal with the dome structure in Dongying Sag, such as the detailed interpretation of three-dimensional seismic data, the coherence cube analysis, and the fault activity analysis techniques. Based on those processingmethods, the fault system spatial characteristics and its evolution of the study area were analyzed. Combined with the single factor analysis and comprehensive fuzzy evaluation, the sealing properties of the main faults in work area were analyzed. Based on all the above, the relationship between hydrocarbon accumulation and distribution and the fault sealing was discussed. The results show that, the Dongying dome structure originated from the upwarp of salt gypsum and plastic mudstone in Kongdian and the fourthmember of theShahejie formati-on thereverse dr-ag o-f thenobounfault-and-the laiterdextral transtensi-onand then was complicated by multi-stage superimposition, multi-directional trending and multi-type array fault systems. The sealing properties of different strata and different parts of the faults show difference. As a whole, in the third to the lower second member of the Shahejie formation, the sealing properties of the second-grade faults were quite good, but those of the third-grade faults were not so good. While in the upper second member of the Shehejie to the Dongying formation, the study of the sealing properties of these faults show that there is a good correlation between fault sealing properties and the reservoirs accumulation and distribution, that is, reservoirs are usually located by the faults with good sealing properties.