曲流河河道砂体油气选择性充注原因——以济阳坳陷新近系为例

Study on petroleum selective injection into meandering stream sand bodies-a case of Neogene in Jiyang depression

以济阳坳陷新近系馆陶组曲流河河道砂体为例,对不同砂组及其内部不同砂体油气选择性充注的原因进行了探讨。断层的活动性是油气纵向输导的主要影响因素,主油源断层和次油源断层控制油气平面分布范围,区域性的储盖组合决定了油气纵向分布层段(砂组),断层和储盖组合是造成不同含油砂组平面和纵向分布差异性的主要因素。河道砂体与断层、构造等的匹配关系是同一区带同一砂组内不同河道砂体油气选择性充注的主要原因。河道砂体的物性条件对油气的选择性充注也具有重要的控制作用,一般在相同的成藏条件下大型河道的物性条件较好,有利于油气聚集成藏。

In Neogene meandering stream channel sand bodies in Jiyang depression,the petroleum usually concentrates in a given pay bed,and only several given sand bodies are filled with petroleum in the given pay bed.The reasons causing these phenomena are discussed in this paper.Firstly,the differentia of fault activity and reservoir-cap assemblage result in the differential distribution of petroleum in meandering stream channel sandstone in different pay beds of different prolific zones.Secondly,the contact relationship between channel sand bodies and transforming faults and structural settings have caused that only several given sand bodies are selectively filled with petroleum in a given pay bed of a given prolific zone.Thirdly,the reservoir characteristics of channel sandstone also influence the selective injection of petroleum into channel sand bodies.Generally,under the same reservoir-forming conditions,the major river channel sand bodies have advantages in reservoir quality and are more easily to concentrate petroleum.The analyses of the reasons of petroleum selective injection have great significance in the zone and play selection,as well as practical well location in the process of petroleum exploration.