卧式沉降罐油水分离效果研究

发布时间：2018-08-12 16:39

【摘要】：随着提高采收率技术在油田的应用,采出液的成分和物性越来越复杂化,致使对油分离技术提出更高要求。卧式沉降罐是广泛应用于油田生产的油水分离设备之一,其分离效率影响因素的定量研究成果可直接指导油田生产。由于卧式沉降罐内部内部流体存在较复杂的流动特征,外加试验研究的成本太大,出于对以上两点的考虑,本文决定借助Fluent流体软件来完成研究内容。基于流体动力学相关理论建立了卧式沉降罐的数学模型,采用多相流欧拉分析方法,结合Realizable k-?模型对卧式沉降罐内部的流场进行了数值模拟,得到了油水两相流在沉降罐内部的分布情况及油水分离效率。本文针对卧式沉降罐内部流体在三种油滴直径、三种油相粘度以及三种入口流速的九个工矿进行了数值模拟,数值模拟的结果显示:油滴直径越大,卧式沉降罐内部油水分离效率越高。原因在于通过斯托克其公式可知,油滴在油水两相流中的上浮速度与其直径成正比,油滴直径越大,其上浮速度越大,油水分离效率越高;油相粘度越大,卧式沉降罐内部油水分离效率越低。原因在于油相粘度增大后,增大了油滴上浮的阻力,增强了水相的携油能力,使得油水分离难度增大,导致油水分离效率降低;卧式沉降罐入口流速越大,卧式沉降罐内部油水分离效率越低。原因在于油水分离是一个动态过程,需要充分的时间。入口流速增加后,导致油水混合物在卧式沉降罐中停留的时间变短,使得油相无法在沉降罐中依靠重力作用进行充分沉降,沉降时间的减少降低了油水分离效率。
[Abstract]:With the application of enhanced oil recovery technology in oil fields, the composition and physical properties of produced fluids are becoming more and more complicated, resulting in higher requirements for oil separation technology. Horizontal settling tank is one of the oil-water separation equipment widely used in oilfield production. The quantitative research results of the factors affecting the separation efficiency can direct the production of oil field. Due to the complex flow characteristics of the fluid in the horizontal settling tank and the high cost of the additional experimental study, this paper decides to complete the research with the help of Fluent fluid software for the consideration of the above two points. Based on the theory of hydrodynamics, the mathematical model of horizontal settling tank is established. The multi-phase flow Euler analysis method and Realizable k-? The numerical simulation of the flow field in the horizontal settling tank is carried out, and the distribution of oil-water two-phase flow in the settling tank and the efficiency of oil-water separation are obtained. In this paper, the numerical simulation of fluid flow in three kinds of oil droplet diameter, three oil phase viscosity and three inlet velocity in nine industrial mines is carried out. The results of numerical simulation show that the larger the oil droplet diameter is, the larger the oil droplet diameter is. The higher the separation efficiency of oil and water in horizontal settling tank. The reason is that the floating velocity of oil droplet in oil-water two-phase flow is proportional to its diameter through Stoker's formula. The larger the diameter of oil droplet, the higher the floatation speed, the higher the separation efficiency of oil and water, and the higher the viscosity of oil phase. The lower the separation efficiency of oil and water in horizontal settling tank is. The reason is that when the viscosity of oil phase increases, the resistance of oil droplet floating is increased, the oil carrying capacity of water phase is enhanced, the difficulty of separating oil from water is increased, and the efficiency of oil water separation is reduced. The higher the inlet velocity of horizontal settling tank is, The lower the separation efficiency of oil and water in horizontal settling tank is. The reason is that oil-water separation is a dynamic process and requires sufficient time. With the increase of inlet velocity, the residence time of oil / water mixture in horizontal settling tank becomes shorter, and the oil phase can not be fully settled by gravity in the settling tank, and the reduction of settling time reduces the separation efficiency of oil and water.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE931.1

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