大庆喇萨杏油田不同类型河道砂体剩余油分布规律研究

Research on Distributive Rules of Remaining Oil in Different Types of Channel Sand-bodies in Daqing Lasaxing Oilfield

大庆喇萨杏油田为大型陆相浅水湖盆河流三角洲沉积体系,发育辫状河、曲流河和水下分流河道3种河道砂体。根据喇萨杏油田不同开发阶段钻取的125口密闭取心检查井的统计分析,研究各类河道砂体水淹动态变化规律,并总结了各类河道砂体分布模式。分析表明,辫状河、曲流河砂体规模相对较大且连续分布,水下分流河道砂体规模窄小,分布零散;辫状河砂体动用比例较大,很难实施进一步挖潜,而曲流河、水下分流河道砂体动用比例相对较低,是进一步挖潜的主要对象;辫状河、水下分流河道砂体以砂体规模窄小型剩余油分布模式为主,曲流河砂体剩余油分布模式以各种遮挡型剩余油为主。

It is a typical continental basin of shallow-water fluvial-delta sedimentary system in Lasaxing Oilfield.The channel sands are mainly consisted of braided,meandering and underwater distributary channel,and the geological reserves in those channel sands account for more than 70% of the water flooded reserves.The remaining oil and watered out characteristic in the channel sands are discussed based on the statistic of 125 inspection well drilled in different times of the field development.The relationship between watered-out thickness and time is established,and the law of watered out performance in different channel sands is thoroughly studied,the remaining oil distribution pattern is given in the paper.Because of the differences in remaining oil controlling factor,the stimulation measures and exploiting strategy should be changed accordingly.The measures are developed based on interlay status and the state of technologies.A new pattern of remaining oil exploiting in the high water cut period is finally promoted,which provides a reference for the related oilfields.