纳微米聚合物颗粒分散体系非匀相渗流理论研究

发布时间：2019-06-29 19:55

【摘要】：纳微米聚合物颗粒分散体系能够深入地层起到调驱作用,有效的改善低渗透油田注水开发效果并提高采收率。纳微米聚合物颗粒分散体系在多孔介质中运移规律复杂,实验中发现颗粒团聚、微观结构变化及选择性进入孔喉等非匀相渗流现象,但对非匀相渗流机理及其对提高采收率的影响仍未有系统研究,因此如何科学的描述纳微米聚合物颗粒分散体系的复杂渗流规律及提高采收率机理就成为纳微米聚合物颗粒调驱技术推广应用的关键问题。隙被驱替相填满,最先被填满的孔隙所需要的时间就是／甲基丙烯酸甲酯(AA/AM/MMA)颗粒,对其非匀相渗流特征及其提高采收率机理开展了一系列实验和理论研究： 1.基于水化膨胀实验和流变实验,建立综合考虑颗粒膨胀动态变化和膨胀聚合物颗粒间作用力的分散体系流变模型,分析了地层环境、剪切速率和水化时间对聚合物颗粒水化膨胀程度及分散体系流变的影响。 2.通过微观仿真可视化实验研究发现,纳微米聚合物颗粒在多孔介质内运移和滞留过程中有两种非匀相渗流现象：颗粒径向浓度分布双层微观结构,不同流动阻力孔喉中颗粒非匀相浓度分布。建立微圆管内聚合物颗粒体积浓度径向非匀相分布数学模型,分析颗粒膨胀程度、剪切模量、溶剂粘度和剪切速率等因素对颗粒分布及分散体系流动规律的影响。引入红细胞局部非匀相分布模型并修正,量化分析聚合物颗粒在孔喉中非匀相分布时浓度变化规律。建立了纳微米聚合物颗粒三维毛管束网络中运移模型,模拟发现聚合物颗粒集中在主流线通道中,调整了流场分布,使得孔喉中流动阻力达到平衡状态。 3.基于两相相对渗透率实验,建立纳微米聚合物体系驱油平行毛管束模型,考虑了聚合物颗粒非匀相浓度分布,模拟分析了分散体系驱油过程中两相相对渗透率变化规律。注入分散体系后油相相渗曲线和等渗点右移,水相相渗曲线末端出现下凹形态,即在高含水饱和度时水相相渗下降。研究发现考虑聚合物颗粒非匀相浓度分布时,中高渗透率通道随着分散体系的持续注入逐步被封堵。 4.基于纳微米聚合物颗粒封堵实验,建立分散体系的阻力系数和残余阻力系数关系表达式。结合聚合物颗粒非匀相浓度分布模型,建立了考虑注入速度、颗粒粒径和颗粒浓度等因素的拟相对渗透率计算模型。水相相渗随着颗粒浓度、注入速度和颗粒粒径的增加而下降。 5.建立纳微米聚合物颗粒分散体系驱油二维网络模型模拟方法,模拟了注入聚合物颗粒后剩余油分布和不同类型剩余油比例,揭示了聚合物颗粒特性对提高采收率的影响。 6.建立非均质分层地层纳微米聚合物颗粒分散体系调驱数学模型,考虑聚合物颗粒的非匀相分布,模拟注聚合物颗粒提高非均质地层采收率的变化规律。阐明了颗粒浓度、注入量和转注时机等因素对影响,揭示了非匀相颗粒浓度分布有利于扩大波及体积。本文通过实验研究、理论分析和数值计算,主要得到了以下认识：颗粒水化膨胀特性是分散体系粘度和非匀相流动的重要影响因素,颗粒膨胀程度越大,固壁边界润滑层厚度越大,颗粒空间非匀相分布现象越显著。颗粒分布双层微观结构使分散体系表观粘度剪切变稀,而颗粒浓度多孔介质内非匀相分布能逐步封堵低流动阻力孔喉,使水相渗透率在高含水饱和度时下降。研究揭示了纳微米聚合物颗粒浓度非匀相分布有利于扩大波及体积,提高低渗层采出程度,为深入分析纳微米聚合物颗粒分散体系驱油机理提供了理论支持。
[Abstract]:The nano-micron polymer particle dispersion system can be used for deep formation to play a role of regulating and driving, effectively improving the water injection development effect of the low-permeability oil field and improving the recovery ratio. The migration of the nano-micron polymer particle dispersion system in the porous medium is complicated. In the experiment, the phenomena of non-uniform phase flow, such as particle agglomeration, micro-structure change and selective entry into the pore throat, are found, but the mechanism of non-uniform phase flow and its influence on the enhanced oil recovery are still not studied. Therefore, how to scientifically describe the complex seepage law of the nano-micron polymer particle dispersion system and the mechanism of enhanced oil recovery become the key problem for the application of the nano-micron polymer particle size-adjusting technology. The time required for the first filled pores is/ methyl methacrylate (AA/ AM/ MMA) particles, and a series of experiments and theoretical research have been carried out on the non-uniform phase flow characteristics and the enhanced oil recovery mechanism. research:1. hydration-based expansion experiment and flow The rheological model of the dispersion system considering the dynamic change of the particle and the interaction force between the expanded polymer particles was established, and the degree of hydration and expansion of the polymer particles and the rheological properties of the dispersion system were analyzed. 2. Two non-uniform flow phenomena in the process of migration and retention of the nano-micron polymer particles in the porous media were found through the micro-simulation and visual experiment. The distribution of the phase concentration is established. The mathematical model of the radial non-uniform phase distribution of the volume concentration of the polymer particles in the micro-circular tube is established. The distribution of the particle and the flow of the dispersion system are analyzed by the factors such as particle expansion, shear modulus, solvent viscosity and shear rate. The effect of the law on the distribution of the local non-uniform phase of the red blood cells was introduced, and the distribution of the polymer particles in the non-uniform phase in the throat of the porous throat was quantified and analyzed. in that present invention, the migration model of the three-dimensional hair bundle network of the nano-micron polymer particle is established, and the simulation result shows that the polymer particle is concentrated in the main flow channel, and the flow field distribution is adjusted, so that the flow resistance in the pore throat in that equilibrium state,3. based on the two-phase relative permeability experiment, a parallel wool bundle model of a nano-micron polymer system is established, the non-uniform phase concentration distribution of the polymer particle is taken into account, and the two-phase relation of the two phases in the dispersion system oil displacement process is simulated and analyzed, The change rule of permeability is as follows: the oil phase and the isoosmotic point are shifted to the right after injection of the dispersion system, and the end of the phase infiltration curve of the water phase is in a concave shape, that is, at the water saturation of the high water content, When the non-uniform phase concentration distribution of the polymer particles is considered, the high permeability channel decreases with the dispersion system. step-by-step plugging.4. Establish the drag coefficient and the residue of the dispersion system based on the nano-micron polymer particle plugging experiment In this paper, the relationship between the resistance coefficient and the non-uniform phase concentration of the polymer particles is established, and the factors such as the injection speed, the particle size and the particle concentration are considered. Relative permeability calculation model. 5. A two-dimensional network model simulation method for the dispersion system of a nano-micron polymer particle is established, and the residual oil distribution after injection of the polymer particles and the proportion of the remaining oil of different types are simulated, and the polymer particles are disclosed. 6. To establish a mathematical model of the dispersion system of a nano-micron polymer particle dispersion system in a heterogeneous layered formation, to simulate the non-uniform phase distribution of the polymer particles and to simulate the improvement of the polymer particles. The influence of the factors such as the concentration of the particles, the injection quantity and the time of the injection is clarified, and the non-uniform phase particles are revealed. The concentration distribution is beneficial to the expansion of the sweep volume. In this paper, the experimental research, the theoretical analysis and the numerical calculation are carried out. The main results are as follows: the hydration and expansion characteristics of the particles are the important factors of the viscosity of the dispersion system and the non-uniform phase flow, and the expansion range of the particles The larger the degree, the greater the thickness of the lubrication layer on the solid wall boundary and the non-uniform phase distribution of the particle concentration porous medium can gradually block the low-flow resistance pore throat, In that study, the non-uniform phase distribution of the particle concentration of the nano-micron polymer is beneficial to the expansion of the sweep volume and the increase of the permeability of the low-permeability layer, so as to further analyze the nano-micron polymer particle.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1

【共引文献】