加密井提高注水开发油田采收率的评价方法

大庆油田杏 4-6 区自 1967 年投入开发至今,先后经历了 3 次加密开发过程。分析 3 次加密后的开发动态资料,得出了评价加密井提高采收率效果的实用方法。3 次加密后的技术采收率分别为 40.1%、53.0%和 57.8%. 从宏观和微观两个方面,对谢尔卡切夫的井网密度法原式进行推导;并利用大庆油田杏 4-6 区等 5 个油田的实际数据,建立了水驱开发油田采收率和井控面积的相关经验公式。将杏 4-6 区的流度值和平均井控面积值代入相关经验公式,得到一次加密后的采收率为 38.7%,这与产量递减法确定的采收率 40.1%很接近,表明相关经验公式的适用性。

A Method for Evaluation of EOR of Waterflooding Oilfield by Infill Well Process

Xin4-6 region in Daqing oilfield has undergone three infill development processes since 1967.The production performance data from these infill processes are analyzed followed by proposing a practical method for evaluation of enhanced oil recovery(EOR)from infill wells.The technical EOR from them is 40.1%,53.0%and 57.8%,respectively.In microscopic and macroscopic aspects,the original formula of Selkachev's network density method is deduced.Using the data from five oilfields in Daqing(Xin4-6 region),Romashikino,Dumaz,Bovilin and East-Texas,a new relative empirical formula for determination of EOR of waterflooding oilfield and well-controlled area is established.The mobility and well-controlled area in Xin4-6 region are substituted into this formula,the primary infilled recovery efficiency equals to 38.7%,which is close to that given by production decline method(40.1%),showing the reliability or practicability of the relative empirical formula.