氮气泡沫驱提高高渗透特高含水油藏采收率技术——以梁家楼油田纯56块为例

N_2 foaming EOR for high permeable and high water cut reservoir——case of block Chun56,Lianjialou oilfield

梁家楼油田纯56块高含水、高采出程度,剩余油主要富集于构造顶部及厚油层上部,常规措施挖潜效果越来越差,剩余储量动用难度大,油藏处于低效开发状况,为此,开展了氮气泡沫驱提高采收率技术的研究。重建了该区的三维地质模型,利用数值模拟进行历史拟合和注入参数优化,预测氮气泡沫驱开发指标及经济效益,通过对氮气水、氮气泡沫同注或交替注入4类36个方案开发指标的分析对比,选择氮气泡沫同注,6口注入井分为3组交替注入2个周期,平均单井氮气注入量为73.6×104m3,起泡剂用量为75t,预计提高采收率5.7%。先导试验选取井组1注7采,6口井见效,综合含水率下降0.8%,增油量为8.1t/d,取得了较好的降水增油效果。

The EOR by nitrogen-foam flooding was implemented in block Chun56 of Liangjialou oilfield,which entered the stage of high wa-ter cut and high recovery percent of reserves,the production potential of conventional development style is lower than expected.the production of remaining reserves becomes more and more difficult,and the reservoir is in low development performance.Three-dimension geological model of the oilfield was reconstructed,and the history matching and injection parameters optimiza-tion were studied through numerical stimulation,the development index of nitrogen-foam flooding and economic benefit were forecasted.Thirty-six project development indexes were analyzed by nitrogen-water injection,nitrogen-foam injection and nitrogen alternate foam injection.Selecting 6 injection wells as three series and injected alternatively with 2 period by nitrogen-foam injec-tion,the average injection volume of N2 is 73.6× 104m3 and the frother quantity is 75t per well,and the recovery efficiency is ex-pected to be improved by 5.7%.Selecting 1 injection well and 7 production wells as the pilot,and 6 production wells achieved good performances,water cut decreased by 0.8%,oil increased by 8.1 t/d,