摘要
把特低渗透油藏岩心根据渗透率划分为不同等级,分别对不同等级岩心进行注水、注氮气和注二氧化碳室内实验。测得了不同开发方式条件下注采压差梯度和洗油效率,回归出不同开发方式下洗油效率随渗透率变化关系式,并对不同开发方式效果进行对比分析。研究结果表明:特低渗油藏在不同方式开发过程中,注入压力都表现为先上升后下降,最后趋于稳定值;由于启动压力的存在,洗油效率在注入开发初期都为零;注氮气开发注采压差大于注二氧化碳开发注采,小于注水开发注采压差;在渗透率较高情况下,注氮气和二氧化碳注采压差相差不大;二氧化碳驱油效果最好,氮气次之,水驱最差。
Ultra-low permeability reservoir cores were divided into different grades according to permeability, then laboratory experiments of different development methods were carried out by water flooding, nitrogen drive and carbon dioxide drive respectively according to different core grades. For different development methods, the pressure gradient and displacement efficiency were measured, the relationship between the displacement efficiency and the permeability was regressed, and the effect of different development methods was compared. Results show that in the ultra-low permeability oil reservoir development process by using different methods, drive pressure increases first, and then decreases, and stabilized at last. Displacement efficiency is zero in the early development stage due to the presence of threshold pressure. The pressure of nitrogen drive is greater than that of carbon dioxide drive but less than that of water flooding. In the case of higher permeability, pressure of nitrogen drive and carbon dioxide drive is almost equal. The driving effect among these methods, carbon dioxide drive is the best, and then followed by nitrogen drive, water flooding is the worst.
出处
《实验力学》
CSCD
北大核心
2011年第4期442-446,共5页
Journal of Experimental Mechanics
基金
国家重点基础研究发展规划"973"项目"温室气体提高石油采收率的资源化利用及地下埋存"(2006CB705804)
泰山学者建设工程专项经费资助项目(TS20070704)
关键词
特低渗透
注水
氮气驱
二氧化碳驱
室内实验
ultra-low permeability
water flooding
nitrogen drive
carbon dioxide drive
laboratory experiment
