油井返排液除砂装置的设计研究与现场应用

发布时间：2018-04-03 01:02

本文选题：返排液　切入点：四相分离　出处：《西安石油大学》2017年硕士论文

【摘要】：钻井过程中采用分段压裂工艺,每口井压裂后产生的返排液约1000m3,如果不经过处理而外排,会对周围环境及地表水系造成严重污染。目前油井返排液的处理方法是将其返排入罐,使其在罐中自然蒸发并通过人力回收砂子。这种方法使得劳动强度大并且不能对返排液回收利用,造成环境污染。针对这些问题,笔者设计了一种集沉降、过滤、回收功能的新型返排液除砂装置,该装置具有对油、气、水、砂四相分离和回收功能。本文主要对返排液除砂装置的设计方案、设计理论、仿真模拟、现场试验进行了深入研究,进行的主要工作和结论如下所示:针对目前油井返排液处理存在的问题,提出一种新型返排液除砂装置,并对除砂装置进行了总体方案设计。说明了除砂装置总体布局及其工作原理,并对主要配套设备进行了选型设计。通过对沉降分离和过滤分离机理的研究,确定了返排液除砂装置的设计理论基础。基于流体力学原理,在不考虑液相流动的不均匀性情况下,进行了除砂能力理论计算分析。基于除砂能力的理论计算分析对除砂装置进行了结构设计计算,并利用Pro/E建立了除砂装置三维实体模型。利用FLUENT仿真计算软件对分离罐内部流场进行仿真模拟并对砂粒运动轨迹和沉积进行追踪,研究发现:砂粒受液相流动边界效应的影响,砂粒碰到壁面后形成附着作用沿壁面下落,造成壁面附近大量砂粒堆积;砂粒直径越小受流场影响越大,在流场中的位移和时间越大;砂粒沉积率随砂粒直径的增大而逐渐升高,随砂粒体积浓度的增加而逐渐降低;当砂粒直径大于0.25mm时,体积浓度降低至5%后油井压裂返排液中98%的砂粒沉积在分离罐内。通过长庆油田某油井现场试验研究表明:除砂装置能够对油井压裂返排液中99%的砂子回收以及对压裂返排液全部回收;砂子回收过程只需1人参与,大大降低了劳动强度。
[Abstract]:In the process of drilling, the fracturing process is adopted, and the amount of fluid produced after fracturing is about 1000m3. If the fluid is discharged out without treatment, it will cause serious pollution to the surrounding environment and surface water system.At present, the treatment method of oil well regurgitation liquid is to put it back into the tank, make it vaporize naturally in the tank and recover sand by manpower.This method makes the labor intensity high and can not be recycled, resulting in environmental pollution.In order to solve these problems, the author designed a new desilting device with the functions of sedimentation, filtration and recovery. The device has the function of separating and recovering oil, gas, water and sand by four phases.In this paper, the design scheme, design theory, simulation simulation and field test of the sand removal device are studied. The main work and conclusions are as follows: aiming at the problems existing in the treatment of oil well reflux,In this paper, a new kind of sand removal device with backflow liquid is proposed, and the overall design of the sand removal device is carried out.The general layout and working principle of the sand removal device are explained, and the type selection design of the main supporting equipment is carried out.Based on the study of settling separation and filtration separation mechanism, the design theoretical basis of the sand removal device for backflow liquid is determined.Based on the principle of fluid mechanics, the theoretical calculation and analysis of sand removal capacity are carried out without considering the inhomogeneity of liquid flow.Based on the theoretical calculation and analysis of the sand removal capacity, the structure design of the sand removal device is calculated, and the three-dimensional solid model of the sand removal device is established by using Pro/E.The flow field in the separation tank is simulated by FLUENT software, and the movement track and deposition of sand particles are traced. The results show that the sand particles are affected by the boundary effect of liquid flow.When sand particles come into contact with the wall, the adhesion is formed along the wall, which results in a large amount of sand accumulation near the wall, the smaller the sand diameter is, the greater the influence of the flow field is, the greater the displacement and the time in the flow field.The sand deposition rate increases with the increase of sand diameter and decreases with the increase of sand volume concentration. When the sand diameter is larger than 5%, 98% of sand particles in fracturing fluid are deposited in the separation tank.The field test of an oil well in Changqing Oilfield shows that the sand removal device can recover 99% sand from fracturing fluid and recover all fracturing fluid, and the sand recovery process requires only one person to participate in the recovery process, which greatly reduces the labor intensity.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE93;X741

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