耐酸颗粒堵剂在低渗透油田注水井中的应用

Application of Acid-resistant Granule Plugging Agent in Injection Well of Low Permeability Oilfield

为改变低渗透油藏地层非均质性,提高地层流体波及体积,降低注水井的注水压力,提高注水量,以膨胀倍数、耐酸性能、封堵性能等为性能指标,优选了一种具有良好抗盐抗酸性能的颗粒堵剂SDJ。研究结果表明,颗粒堵剂SDJ在60℃、50000 mg/L模拟盐水中膨胀倍数可达8.5倍,酸化处理后膨胀保留率最高可达20.83%;对渗透率为997×10^(-3)μm^2的填砂管的封堵率达到99.5%以上,对渗透率为1.824×10^(-3)μm^2的岩心的封堵率可达94.7%。现场试验结果表明,耐酸颗粒堵剂SDJ加入后升压2.0 MPa左右,注酸后注水压力下降6.0 MPa,注水排量提升40.6%,降压增注效果良好,吸水剖面得到明显改善。

In order to improve formation heterogeneity of stratum,increase sweep volume of displacement agent,reduce water injection pressure and increase water injection capacity,a kind of particle plugging agent SDJ with good salt and acid resistance was selected from the aspects of expansion ratio,acid resistance and plugging performance.The results showed that the swelling ratio of SDJ was 8.5 times in simulated brine with salinity of 50000 mg/L at the temperature of 60℃.The swelling retention rate was up to 20.83%after acidification treatment.The plugging rate in sand filling pipe with permeability of 997×10^-3μm^2 was over 99.5%.The plugging rate in core with permeability of 1.824×10^-3μm^2 was 94.7%.Field test results showed that the pressure was raised by 2.0 MPa after injection of the acid-resistant granules,and the water injection displacement was increased by 40.6%after acid injection,and the water injection pressure was reduced by 6.0 MPa.The effect of depressurization and injection-increasing of SDJ was excellent,and the injection profile was modified obviously.