分散凝胶与孔喉匹配关系及调驱机理研究

发布时间：2018-02-16 04:28

本文关键词： 分散凝胶孔喉匹配关系运移与滞留模式调驱机理　出处：《西南石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：分散凝胶是将交联体系在地面交联形成的颗粒凝胶,具有粒径小、数量庞大、悬浮分散性好、弹性高和适用范围广等特点。因此在深部调驱领域,分散凝胶极具应用潜力。目前分散凝胶的应用受到一定限制,主要原因是颗粒与地层孔喉的配伍性难以控制,往往只在注水井附近的油层中起到封堵作用,水会很快绕流,再次进入高渗带,致其深部调驱作用受限。为此,本文主要对分散凝胶与孔喉匹配关系及调驱机理开展一系列实验和理论研究。采用反相乳液聚合法制备了微米级分散凝胶,并对其基本物理化学性质进行表征。该凝胶颗粒圆球度好,能够均匀地分散在水中,具有良好的热盐稳定性、水化膨胀特性和黏弹性。利用微孔膜渗滤装置、SEM、激光粒度仪和紫外分光光度计等实验手段,并结合岩心驱替实验,研究了分散凝胶与孔喉匹配关系的影响因素,分析得出颗粒运移与滞留机理,以及建立了综合考虑匹配因子、质量浓度、颗粒弹性和渗流速度的凝胶颗粒运移和堵塞经验数学公式。结果表明:随着匹配因子增加,分散凝胶的运移与封堵类型依次为:"顺利通过"、"低效封堵"、"高效封堵"和"完全封堵"。随着渗流速度降低或颗粒弹性/质量浓度升高,分散凝胶与孔喉匹配程度增高;匹配因子处于较佳范围内,匹配因子小而弹性高的颗粒在多孔介质中的封堵性能更加优异。颗粒在多孔介质中的运移与滞留模式为:①顺利通过,②沉积与释放,③弹性封堵—再次运移,弹性封堵可细分为捕获封堵、重合封堵和架桥封堵。再次运移包含以下三个过程:弹性变形,稳定运移/破碎通过,弹性恢复。④完全封堵。通过二维可视化平板实验直观形象地展示了不同驱替阶段的流体分布情况,量化了各个阶段高、中和低渗带的面积波及效率以及洗油效率。利用核磁共振从微观角度定量分析驱替阶段各孔喉区间采出程度及颗粒弹性对提高采收率的影响。油水两相相渗实验表明:与水驱相比,凝胶颗粒驱相渗曲线的右端点右移,油水两相等渗点右移,油水相渗透率不均衡降低。随着颗粒浓度的增加或渗流速度的减小,驱油效率提高。基于上述实验研究,得出分散凝胶调驱机理为:①颗粒优先进入高渗层,进行选择性调驱。②沉积—释放和弹性封堵—再次运移实现深部液流转向。③颗粒弹性变形将孔壁表面的油膜剥落;颗粒弹性恢复将孔喉盲端的残余油"挤"出来;颗粒从孔喉中突破,形成瞬时"负压"。④油水相渗透率不均衡降低。
[Abstract]:Dispersion gel is a kind of granular gel formed by cross-linking crosslinking system on the ground. It has the characteristics of small particle size, large quantity, good suspension dispersion, high elasticity and wide application range. Dispersion gels have great potential for application. At present, the application of dispersed gels is limited to a certain extent, mainly because the compatibility of particles with formation pore throats is difficult to control, and often only plays a plugging role in the reservoir near the injection wells, and the water will flow around quickly. In this paper, a series of experimental and theoretical studies were carried out on the matching relationship between dispersed gel and pore throat, and on the mechanism of control flooding. Micron dispersible gel was prepared by inverse emulsion polymerization. The basic physical and chemical properties of the gel particles were characterized. The gel particles have good sphericity, can be uniformly dispersed in water, and have good thermal and salt stability. Hydration expansion characteristics and viscoelasticity. By means of microporous membrane percolation apparatus (SEM), laser particle size meter and ultraviolet spectrophotometer, combined with core displacement experiment, the influencing factors of the matching relationship between dispersed gel and pore throat were studied. The mechanism of particle migration and retention and the empirical formula of gel particle migration and blockage considering matching factor, mass concentration, particle elasticity and percolation velocity are established. The results show that the equation increases with the increase of matching factor. The types of migration and plugging of dispersed gels are as follows: "smooth passage", "low efficiency plugging", "high efficiency plugging" and "complete plugging". The matching degree between dispersed gel and pore throat increases with the decrease of percolation velocity or the increase of particle elastic / mass concentration. The matching factor is in a better range. Particles with small matching factor and high elasticity have better plugging performance in porous media. The migration and retention mode of particles in porous media is as follows: 1. Elastic plugging can be subdivided into capture plugging, superposition plugging and bridging plugging. Remigration consists of the following three processes: elastic deformation, stable migration / breaking through, Elastic recovery 4. 4 complete plugging. The fluid distribution in different displacement stages is visualized by two-dimensional visual plate experiments, and each stage is quantified. Area sweep efficiency and oil washing efficiency of middle and low permeability zone. Quantitative analysis of the effect of recovery degree and particle elasticity on oil recovery by nuclear magnetic resonance (NMR) in each pore throat interval in displacement stage. Oil-water two-phase permeation experiment. The results show that: compared with water drive, With the increase of particle concentration or the decrease of percolation velocity, the oil displacement efficiency increases with the increase of particle concentration or the decrease of percolation velocity, and the oil displacement efficiency increases with the increase of particle concentration or the decrease of percolation velocity, and the oil displacement efficiency increases with the increase of particle concentration or the decrease of percolation velocity. It is concluded that the mechanism of dispersed gel flooding is that the particles of 1 / 1 are preferentially entered into the high permeability layer, and the oil film on the surface of the pore wall is peeled off by selective adjusting flooding .2 Sediment- release and elastic plugging-re-migration to realize the deep liquid flow turning to 3. 3 particles elastic deformation. The residual oil from the blind end of the pore throat was squeezed out by the particle elastic recovery, and the particle broke through the pore throat, forming an instantaneous "negative pressure" .4 oil and water phase permeability imbalance reduced.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357.46

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