姬塬油田X区聚合物微球驱效果评价

Evaluation of polymer microsphere flooding effect in block X of Jiyuan oilfield

姬塬油田X区块长6油藏属于特低渗透油藏,目前综合含水51.1%,已进入中含水开发阶段,随着注水开发时间的延长,调驱技术的需求度更高,目前该区块水驱矛盾突出导致含水上升,而聚合物微球深部调驱技术则是针对储层深部剩余油,通过小粒径、低浓度、微球在储层深部的滞留降低高渗层渗透率,降低高渗水流速度、改变压力场分布、进而改变渗流场、达到改善水驱的目的,为此本文结合2021年1月以来微球驱现场应用及效果评价,对微球驱在X区适应性进行评价,总结调驱经验,为微球驱的推广与实施提供指导性意见。现场应用试验结果表明,当注入微球粒径为100 nm,浓度为1 500 mg/L时,调驱封堵效果较好,水驱效果得到一定的改善,注入端压力上升,水驱波及体积变大,油井端流压下降。2020年12月~2021年11月,调驱井组注入压力从11.9 MPa上升到12.3 MPa,井底流压从4.10 MPa下降到3.88 MPa。侧向井和角井以孔隙见水为主,调驱效果较好,侧向井和角井的调驱增油型见效比例分别可达39.5%和51.2%。

Chang 6 reservoir in block X of Jiyuan oilfield belongs to ultra-low permeability reservoir. At present, the comprehensive water cut is 51.1%, and has entered the medium water cut development stage. With the extension of water injection development time, the demand for profile control and flooding technology is higher. At present, the prominent contradiction of water drive in this block leads to the increase of water cut, while the polymer microsphere deep profile control and flooding technology is aimed at the deep remaining oil of the reservoir through small particle size, low concentration,the retention of microspheres in the deep reservoir reduces the permeability of high-permeability reservoir, reduces the highpermeability water flow velocity, changes the pressure field distribution, and then changes the seepage field to improve water drive. Therefore, combined with the field application and effect evaluation of microsphere drive since January 2021, this paper evaluates the adaptability of microsphere drive in zone X and summarizes the experience of profile control and drive,provide guidance for the promotion and implementation of microsphere flooding. The field application test results show that when the particle size of injected microspheres is100 nm and the concentration is 1 500 mg/L, the plugging effect of profile control and flooding was better, the water drive effect was improved to a certain extent, the pressure at the injection end increased, the swept volume of water drive increased, and the flow pressure at the oil well end decreased. From December 2020 to November 2021, the injection pressure of profile control and flooding well group increased from 11.9 MPa to 12.3 MPa, and the bottom hole flow pressure decreased from 4.10 MPa to 3.88 MPa. Lateral wells and angle wells were dominated by pore water, and the effect of profile control and flooding was good.The effective proportion of profile control and flooding and oil increase type of lateral wells and angle wells could reach 39.5% and 51.2% respectively.