基于沉积过程点坝内部结构对剩余油分布影响——以大庆油田萨北地区为例

Influence of Point Bar Internal Structure on Remaining Oil Distribution Based on the Depositional Process

为了研究高含水期曲流河点坝内部结构对剩余油分布的影响,对大庆油田萨北地区两个研究层进行河流演化过程重塑及点坝内部解剖。首先根据砂体厚度以及砂体测井响应识别单一河道,再根据不同单河道中废弃河道最终位置,分析河流的摆动过程,重塑河流演化过程和迁移规律,然后在此基础上刻画点坝内侧积体及夹层属性,综合水淹资料和岩石薄片资料对点坝内剩余油进行分析。分析认为,点坝内有两种特殊侧积体,一种是"封闭式"侧积体,另一种是"半通式"侧积体,两种侧积体都具有良好的夹层起屏蔽作用,油气在其中聚集难以被驱替,是点坝内主要剩余油来源。

In order to study the influence of point bar internal structure on remaining oil distribution in high water ratio meandering river,two Research layers in Sabei Area of Daqing Oil Field were taken as an example to show the process of river evaluation and point bar sand dissection. Single channel through the sand thickness and response of sand log can be distingushed,then the rivers swing process、remode evolution and the migration of the river are analyzed according to the eventually position of the abandoned channel in different single river. At last,According to flooding information and data sheet rock the remaining oil was analyzed. The results show that there are two lateral accretion body,Closed and Semi-connected lateral accretion body,both of them are the main source of remaining oil in point bar because those interlayer play a shield role in which the oil-gas resource is hard to displace.