加密井提高注水开发油田采收率的评价方法

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

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。

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 oiffield and well-controlled area is established. The mobility and weN-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.