非均相复合驱油体系设计与性能评价

为进一步提高聚驱后油藏采收率,针对聚驱后油藏非均质性强、剩余油普遍分布的特点,提出了非均相复合驱油体系。非均相复合驱油体系包括黏弹性颗粒驱油剂(PPG)、表面活性剂和聚合物。通过研究黏弹性颗粒驱油剂的溶胀能力、黏弹性、滤过能力和在岩心中运移性能,及其与表面活性剂、聚合物之间相互作用,得到了适合于胜利高温高盐油藏和聚合物驱后油藏的非均相复合驱油体系1000mg/L PPG+1000mg/L聚合物+0.3%胜利石油磺酸盐+0.1%非离子表面活性剂1709。结果表明,PPG可遇水溶胀,耐盐性能好,在油藏中具有封堵和运移性能,较单一聚合物能够更好地提高波及体积。在含水98%条件下注入0.3倍孔隙体积的非均相复合驱油体系,聚合物驱后提高采收率13.6%(OOIP)。该体系可应用于高温高盐油藏或聚合物驱后油藏大幅度提高采收率。

Design and Performance Evaluation on the Heterogeneous Combination Flooding System

In order to enhance the oil recovery after polymer flooding, the heterogeneous phase combination flooding system(HPCF) consisting of surfactant, polymer and preformed particle gel(PPG) was designed for the strong heterogeneity of reservoir and the widely distributed remaining oil. The dilative capacity, viscoelastic properties, filterability and migration in cores for a series of synthesized PPG, and the interactions between PPG and polymer and the influences of PPG plus polymer on IFT were investigated. The results showed that PPG was a kind of viscoelastic dilative particle in brine and could be migrated under injection pressure in cores. The effective HCFS used for high temperature and salinity reservoir and post polymer flooding reservoir was as 1000 mg/L PPG+1000 mg/L polymer+0.3% Shengli petroleum sulphonate+0.1%nonionic surfactant 1709. The enhanced oil recovery was 13.6%(OOIP) after polymer flooding when 0.3 pore volume HPCF fluid was injected at water cut of 98%.