化学复合驱技术研究与应用现状及发展趋势

近年来化学复合驱技术应用基础研究及现场试验得到了长足发展。国内采用低浓度复合驱体系,通过碱、表面活性剂的协同作用,降低油水界面张力达到超低数量级,同时采用抗盐聚合物使污水配制驱替液黏度达到要求,三元复合驱或二元复合驱具有提高驱油效率和扩大波及体积双重作用。大庆油田三元复合驱先导性试验和工业化试验提高采收率幅度达到18.6%～26.5%,复合驱进入工业化推广应用阶段,在复合驱试验过程中逐步形成了系列配套技术。复合驱存在的主要问题为强碱引起的检泵周期较短和采出液处理难度大、成本高。国外复合驱技术早期主要采用表面活性剂胶束-聚合物驱,由于成本高未能推广应用,近年来随着油价上涨,开始研究低浓度复合驱体系。国外采用化学驱的油藏大部分为高温高盐油藏,瓶颈技术为耐温抗盐驱油剂的研制。

Current development and application of chemical combination flooding technique

Great success has been achieved in the fundamental study and field test of chemical combination flooding in recent years. In China, a low concentration ASP formula is employed to achieve ultra-low interfacial tension by the synergistic effect of alkali and surfactant. The viscosity of polymer solution made from produced water can meet the technological requirement when salt tolerance polymer is applied. ASP or SP flooding can increase oil displacement efficiency and enlarge the sweep volume simultaneously. ASP pilot test and industrial field test in Daqing Oilfield have resulted in an oil recovery ncrease of 18.5%-26.5%. The chemical combination flooding has entered into the industrial promotion and application stage, with a series of supporting techniques formed in the field tests. The main challenges in this technique include short pump-checking period and difficulty in produced liquid handling and high cost. Micelle-polymer flooding as the major chemical flooding technique was applied abroad in the early stage of chemical flooding test. However, the micelle-polymer flooding has not been applied widely due to its high cost. With the rise of oil price in recent years, low concentration chemical combination flooding has drawn more attention. Because of high temperature and high salinity in most reservoirs abroad where chemical combination flooding is used, high performance temperature and salt tolerance oil displacement agents are the bottleneck for future chemical flooding.