【作者】 刘卫东；

【导师】 黄延章；

【作者基本信息】 中国科学院研究生院（渗流流体力学研究所） ， 流体力学， 2011， 博士

【摘要】 论文以实验研究为基础,全面研究分析了影响二元驱驱油效果的主要影响因素,并在研究的基础上对矿场试验提出建议。针对新疆克拉玛依油田七中区油藏条件,提出适合该区块的聚合物/表活剂二元体系配方,通过聚合物的理化性能以及注入性(阻力系数和残余阻力系数)的研究,结合七中区聚合物驱的现场注入情况,推荐了该区块二元驱所使用聚合物。从界面张力、增粘性、洗油效率、长期稳定性、吸附稳定性、改善流度能力等方面研究了二元体系的性能,并对聚合物、表活剂之间的相互作用进行分析。确定了界面张力范围为100～10-3的二元体系配方,优化出适合不同配方的表活剂。通过岩心实验确定七中区适合二元体系/原油粘度大于2.0,界面张力的最佳值在10-3mN/m,二元驱极限提高采收率24.24%。聚合物/表活剂二元驱提高采收率微观机理包括：油膜的剥离乳化、盲端残余油启动、乳状液的携带、油滴的拉丝运移、油滴的切割、油滴的壁面运移以及孔道中残余油的启动等。与聚驱相比,二元驱启动残余油的能力更强。与三元驱相比,鉴于二元驱启动残余油能力较弱,可考虑在二元驱注入初期加入适量的碱,提高二元驱启动原油的能力,以达到既降低碱带来的负面影响,又最大限度提高二元驱采收率的目的。微观模型中驱替孔道中残余油需要的二元体系/原油粘度比在1.0以上。聚合物粘弹性在二元驱中作用明显,随着粘度比的增大,弹性的贡献率增大；随着界面张力降低,采收率明显增加,驱替孔隙中的残余油需要超低的界面张力。二元驱油过程中,低毛管数下函数点较为分散,高毛管数下函数点较为集中。相对渗透率为饱和度和毛管数的二元函数,在同一饱和度值下,相对渗透率随着毛管数增加而增加,并且随油相增加的幅度更大,从而使得油相分流量增加；提出了相对渗透率是饱和度与毛管数二元函数的实验依据,建立了考虑毛管数变化的二相渗流方程：扩展了Buckley—Leveert两相流渗流理论,将其应用于二元等化学驱渗流机理方面,将会得到了一些新的概念和新现象。更多还原

【Abstract】 Basing on Experimental research, a comprehensive analysis of the main factors affecting oil displacement efficiency of binary flooding was carried out, and some suggestions for pilot test was given.As for reservoir conditions of Qizhong area in Karamay Oilfield, polymer/surfactant binary system formulations for this block was proposed, further in combination with Polymer injection-site situation in Qidong area and by studying the physical and chemical properties and injection ability (resistance coefficient and residual resistance coefficient) of polymer, the polymer used for binary polymer flooding in this very block was recommended.The interfacial tension, viscosity enhancing ability, oil displacement efficiency, long-term stability, adsorption stability, improving mobility abilities of the binary system were studied, and the interaction between polymer and surfactant was analyzed. The binary system formulations with Interfacial tension in the range of 100～10-3 of were determined, and surfactants for different formulations were optimized.By core experiments, that viscosity ratio between binary systems and oil of Qizhong area is greater than 2.0 was determined, and the optical interfacial tension is 10-3mN/m, the binary flooding systems can enhance oil recovery by 24.24% at the utmost.Polymer/surfactant binary Flooding microscopic mechanisms include: denudating and emulsifying oil film, starting blind-end residual oil, carrying emulsion, drawing and moving oil droplets, cutting oil droplets, oil droplets shifting along the wall and starting residual oil in the channel and so on. Compared with the polymer flooding, the ability to start more residual oil of binary flooding is greater.Compared with the ternary flooding, given that the ability to start residual oil of binary flooding is weak, appropriate amount of alkaline can be added in the early stage of injection to enhance the ability of starting residual oil to reach the goal of reducing the negative effects of alkali, but also to maximize the enhancing oil recovery of binary flooding.Viscosity ratio between binary systems and oil in Micro-pore model needs to be above 1.0. Viscoelasticity of polymer flooding plays a great role, as the viscosity ratio increases, the flexibility contribution rate increases; with the interfacial tension reduction, recovery was significantly increased. To displace residual oil in the pores, ultra-low interfacial tension is necessary.In binary flooding process, low capillary number makes that the function points are more dispersed while high capillary number makes that the function points are more concentrated. Relative permeability is the dual function of saturation and capillary number, in the same saturation value, the relative permeability increases with increasing capillary number, and the even larger increase with oil, making oil fractional flow increased. The basis of that Relative permeability is the dual function of saturation and capillary number was proposed, and two-phase flow equation considering changes in the capillary number was established:Buckley-Leveert two-phase flow theory was extended, which will obtain some new concepts and new phenomenon when it is applied to porous flow mechanism of chemical flooding.更多还原