稠油降黏/泡沫复合驱提高稠油采收率

Enhanced Oil Recovery of Viscous-reducing/Foam Combination Flooding for Heavy Oil

江建林 秦 冰 曹凤仪 乔富林

JIANG Jianlin QIN Bing CAO Fengyi QIAO Fulin

针对普通稠油注水开发效果差、化学降黏驱不能有效提高驱替过程中的波及效率的问题，以N，N-二甲基 胺、3-氯-2-羟基-丙磺酸钠、烷基醇聚氧乙烯醚硫酸铵盐为原料，研制了具有降黏和起泡功能的复合驱油体系。 研究了部分水解聚丙烯酰胺对稠油乳化降黏效果的影响，以及聚合物、油藏压力和稠油对驱油体系起泡能力与 稳定性的影响；对比了聚合物/降黏复合驱、聚合物/降黏/泡沫复合驱提高稠油采收率的效果。结果表明，在质量 分数为 0.3%、温度 30～80 ℃、油水体积比为 7∶3 的条件下，复合驱油体系可使稠油黏度从 1607 mPa·s 降至 35.0～60.3 mPa·s，降黏率达到96%以上；加入聚合物能提高复合驱油体系在更低浓度下的降黏能力。复合驱油 体系具有良好的起泡性能。随着油藏压力增加、稠油含量提高，泡沫稳定性明显增强。在70 ℃下，压力由1 MPa 升至13 MPa时，泡沫的半衰期由8 min提高至120 min。稠油稳定泡沫的作用明显。聚合物主要通过提高黏度、 降低泡沫液膜的排液速度、增强膜的强度来提高稳定性。在物理模拟驱油实验中，聚合物/降黏复合驱体系可在 水驱基础上提高稠油采收率10.05百分点。在注入聚合物/降黏复合驱油体系后再注入氮气，复合驱效果得到大 幅提高。注入气体后生成的泡沫有效提高了驱替过程中的波及效率，聚合物/降黏/泡沫复合驱提高采收率达到 22.0 百分点。降黏/泡沫复合驱技术能实现降黏与剖面调整一体化，对水驱稠油提高采收率具有良好的应用 前景。

To address the issues of poor efficiency of water flooding and low swept volume of chemical viscosity reducers for the conventional heavy oil development，a composite oil displacement system with viscosity reduction and foaming features was developed by using N，N-dimethylamine，sodium 3-chloro-2-hydroxypropane sulfonate and alkyl alcohol polyoxyethylene ammonium sulfate as raw materials. The effects of partially hydrolyzed polyacrylamide（HPAM）on emulsification and viscosity reduction of heavy oil，as well as the effects of polymer，reservoir pressure and heavy oil on the foaming ability and stability of oil displacement system were systematically investigated. The heavy oil recovery of polymer/viscosity reduction composite flooding with and without foam flooding was compared. The results showed that the introduction of HPAM improved the viscosity reduction ability of composite oil displacement systems at the lower concentrations. Under the temperature of 30—80 ℃、mass fraction of 0.3% and an oil-water volume ratio of 7∶3，the composite oil displacement system（referred to as SKY）could reduce the viscosity of heavy oil from 1607 mPa·s to 35.0—60.3 mPa·s，and then reach a high viscosity reduction rate of 96%. Meanwhile，SKY also exhibited excellent foaming performance. The stability of foam was significantly enhanced with the increase of reservoir pressure and heavy oil content. The half-life of foam increased from 8 min to 120 min when the pressure rose from 1 MPa to 13 MPa at 70 ℃. Heavy oil had obvious effect of stabilizing foam. The polymer improved the stability of foam mainly by increasing the viscosity，reducing the drainage rate of foam liquid membrane，and enhancing the strength of membrane. The physical simulation flooding experiments revealed that the polymer/viscosity reduction composite flooding system improved the recovery rate of heavy oil by 10.05 percentage points. After the injection of polymer/SKY and nitrogen，the effect of combination flooding was greatly improved. The produced foam after the injection of gas enhanced sweep efficiency during displacement，so the recovery rate of polymer/viscosity reduction/foam combination flooding was increased by 22.0 percentage points. Therefore，the viscosity reduction/ foam combination flooding technology could realize the integration of viscosity reduction and profile adjustment，which had great application prospects for enhancing heavy oil recovery by water flooding.

10.19346/j.cnki.1000-4092.2024.02.012