胜二区沙二段3砂层组氮气泡沫驱提高采收率技术研究

Study on Technology of Nitrogen Foam Flooding for EOR in Es3 2of Shengtuo Oilfield

以胜坨油田二区(简称胜二区)沙河街组二段3砂层组先导性试验区为研究对象,针对储层的非均质特征以及主力层顶部剩余油富集的特点,采用数值模拟与矿场试验相结合的方法,研究了低张力氮气泡沫驱油体系,利用其耐温抗盐、封堵能力强,"堵大不堵小,堵水不堵油"和界面张力低的特点,结合优选出的交错行列式井网,可进一步扩大波及体积,提高洗油效率,从而提高采收率。已在矿场开展单井试注试验,取得了较好效果,确定采用井口气液混合注入方式,气液比为1∶1,预计矿场实施可提高采收率8%,为胜利油区三类高温高盐油藏的有效开发起到指导作用。

By taking the pilot area in Es3 2sand group in the 2nd Region of Shengtuo Oilfield as research object,according to the characteristics of the heterogeneity and the remaining oil enrichment on the top of main reservoir,the foam flooding system of low interfacial tension was researched by using the method of simulation combined with field test.Its characteristics of temperature and salt resistance,strong sealing ability,plugging big pore and not small one,not oil but water,and low interfacial tension were used and combined with optimized and selected staggered row-column network,the sweep volume was expanded for enhancing oil displacement efficiency.The technology is used for field test of single well injection and better effect is obtained,the method of wellhead mixed injection of gas and fluid,the gas-liquid ratio is 1∶1,the predicted oil recovery enhancement is 8%.It provides guidance for the effective development of Type III high temperature and pressure reservoirs in Shengli Oilfield.