濮城油田西区沙二下油藏综合治理研究
2021-09-10盖洁超
盖洁超
摘要:濮城油田西区沙二下油藏的开发已经进入到高含水开发后期,由于受到低油价影响,措施工作量急剧减少、事故井大幅度增加、井网损壞严重、水驱效果变差。油藏的开发效益逐年降低,处于低效开发阶段。本文主要基于濮城油田西区沙二下油藏目前开发中存在的问题进行简要分析,并制定出相对的治理思路和对策。
关键词:濮城油田、西区沙二下、综合治理、开发效益、水驱开发
Abstract: The development of lower ES2 reservoir in the western area of Pucheng Oilfield has entered the late stage of high water cut development. Due to the influence of low oil price, the workload of measures is sharply reduced, the number of accident wells is greatly increased, the well pattern is seriously damaged, and the water drive effect is poor. The development benefit of the reservoir is decreasing year by year, and it is in the low efficiency development stage. This paper mainly analyzes the problems existing in the development of the lower ES2 reservoir in the west area of Pucheng Oilfield, and formulates the relative control ideas and countermeasures.
1.油藏地质特征
西区沙二下油藏位于河南省濮阳市范县境内,濮城长轴背斜构造的西北部,南北长约5km,东西宽约3km,构造面积约8.2km2。油藏动用含油面积5.1km2,动用石油地质储量632.0×104t,标定采收率37.42%,标定可采储量236.47×104t。濮城油田西区沙二下油藏位于濮14断层以北、濮31、46、49断层以西,内部被濮3-73断层、濮4断层分割为濮4块和复杂块。濮3-73、濮4断层以西,构造简单、称为濮4断块区,以东称为复杂断块区。西区沙二下地层岩性主要为不等厚互层状的紫红色泥岩与棕褐色含油粉砂岩。西区沙二下油藏地面原油密度为0.8446-0.8484g/cm3,地层原油密度为0.6741-0.7645g/cm3。地面原油粘度为8.34-10.28mPa·s,地层原油粘度为0.99-1.6mPa·s。原始油气比146-205m3/t。
2.油藏开发历程
西区沙二下1-8油藏于1981年正式投入开发,分沙二下1-4、沙二下5-8两个层系注水开发,依据其开发特点,可分为六个阶段:初步开发阶段(1980-1983年),调整稳产阶段(1984-1991年),高含水递减阶段(1992-2002年),重建井网恢复产能阶段 (2003-2007年),精细注采调整阶段(2008-2014年),低油价递减阶段(2015-2019年)。
3.存在问题
①事故井影响导致井网损坏,注采失调,水驱储量损失大。……
