复杂断块致密油藏CO_(2)驱油和埋存可行性研究

Feasibility study on the CO_(2) flooding and storage in the complex fault-block tight oil reservoirs

金南复杂断块致密油藏,经过多年的衰竭和注水开发,目前面临注水部位产油井含水率高,衰竭部位地层能量严重亏空,单井采油速度低,区块整体采出程度低等问题.针对这些开发问题,本文以金南复杂断块致密油藏为目标,进行了注CO_(2)驱油和埋存的可行性研究.应用地质建模技术和油藏数值模拟技术,对油藏开发历史进行了拟合,并对剩余油进行了分析,在此基础上,进行了开发方式优选、井网完善分析和注气参数优化研究.研究结果表明:对于压裂投产的断块致密油藏,CO_(2)水气交替(WAG)驱可以有效的提高原油采收率;完善的井网是注气开发的保障,注入压力、段塞比、关井气油比、生产流压等参数是WAG驱的关键参数;WAG驱不仅能提高复杂断块致密油藏的原油采收率,还能实现CO_(2)的有效埋存,从而实现经济与环保的双重效益.

After years of depletion and water flooding development,Jinnan complex fault-block tight oil reservoir is now facing problems,such as high water cut of production wells in water flooding block,serious depletion of formation energy in depletion block,low single-well oil production rate and low overall oil recovery degree in the block.To solve these problems,this paper takes the complex fault-block tight reservoir in Jinnan as the target,and studies the feasibility of CO_(2) flooding EOR and storage.Based on the reservoir development history matching and remaining oil analysis by the geologic modeling technology and reservoir numerical simulation technology,the development mode optimization,well pattern improvement analysis and gas injection parameter optimization are studied.The results show that CO_(2) WAG flooding can effectively improve oil recovery in fault-block tight oil reservoirs.Perfect well pattern is the guarantee of gas injection development.Parameters such as injection pressure,slug ratio,shut-in gas-oil ratio and production flowing bottom-hole pressure are the key parameters of WAG flooding.WAG flooding can not only improve oil recovery in complex fault-block tight reservoirs,but also achieve effective CO_(2) storage,thus achieving both economic and environmental benefits.