中原油田提高采收率优化技术

中原油田相继开展了CO2吞吐、N2驱、空气驱、合成聚合物驱、交联聚合物驱、微生物采油等项现场试验。鉴于中原油田地层温度高、地层水矿化度高,常规三次采油技术难以适应。对中原油田提高采收率的技术进行优化分析,对油田地质特点、开采特点和不同类型油藏采收率现状进行归纳,并对各技术潜力进行分析,得出结论:从储层条件和原油性质来看,适用中原油田的三次采油方法是CO2混相驱、天然气非混相驱,其次是化学驱。研究预测显示,通过水驱综合调整和气驱,可提高采收率11.1个百分点,达到40.5%,其中水驱综合调整增加可采储量3841×104t,提高采收率7.4个百分点,三次采油提高采收率3.7个百分点。总结出中原油田提高采收率的方向和思路:水驱提高采收率仍是油田当前开发的重点,重组开发层系、强化差层开采、提高油藏水驱采收率,大力发展堵水调剖等配套工艺技术、提高水驱控制程度,气驱仍是今后的主要发展方向。

The Optimization Technique of Enhancing Recovery Efficiency in Zhongyuan Oilfield

Field tests have been made on CO2 stimulation,N2 drive,air injection displacement,synthetic polymer flooding,cross-linked polymer flooding and microbial oil recovery successively.Normal tertiary oil recovery isn′t fit for Zhongyuan oilfield with high reservoir temperature and formation water salinity.The techniques of enhancing oil recovery in Zhongyuan oilfield are optimized,and geologic and development features and current recovery condition of different types of oil reservoirs of Zhongyuan oilfield are summed up.After the analysis of technique potential,it draws the conclusion that CO2 miscible flooding,natural gas immiscible flooding first and then chemical flooding are fit for Zhongyuan oilfield from the reservoir condition and oil nature.Research shows that recovery efficiency can be enhanced by 11.1percentage point to 40.5% in Zhongyuan oilfield by integrated waterflooding adjustment and gas drive.Among them,increased recoverable reserves are 3841×104t and enhanced oil recovery is 7.4 percentage point by integrated waterflooding adjustment,and improved oil recovery is 3.7 percentage point by tertiary oil recovery.The direction and thinking for enhancing oil recovery in Zhongyuan oilfield are summarized that enhancing oil recovery by water flooding is still the key of current development in Zhongyuan oilfield.In the future,the main direction include restructuring development layer series,strengthening development of bad layers,improving waterflooding recovery of reservoir,developing mating technology of water plugging and profile controlling,improving waterflooding control degree and gas driving.