大斜度井大修作业管柱动态力学行为仿真研究

发布时间：2018-05-13 22:26

本文选题：修井作业 + 大斜度井　；参考：《西南石油大学》2016年硕士论文

【摘要】：随着大斜度井工艺在油田的大量应用,大斜度井的修井工况也越来越复杂。其井斜角大,水平位移长的特点,使得修井作业过程中管柱的轴力和扭矩在井筒中的传递困难。同时,由于修井管柱的直径小、刚度低,增加了大修作业的风险。正确认识大斜度井修井管柱在井筒中的受力对提高修井效率、保障修井安全、降低修井成本至关重要。本文在前人研究的基础上,针对大修井作业管柱力学认识相对薄弱的问题从实验和模拟两方面进行了研究。结合室内台架实验对修井工具作业过程中的钻压与扭矩模型进行了研究,建立了大斜度井大修作业全井管柱与套管(或井壁)的有限元仿真模型,并进行了现场实验验证；根据建立的有限元模型,研究了大斜度井大修作业参数敏感性问题；模拟了多种工况下的杆柱力学行为,对修井作业管柱组合及钻压范围提出了指导意见。主要研究工作如下：(1)修井管柱力学行为模拟有限元建模方法研究：根据修井管柱与井壁之间的接触特点,对管柱与井壁之间的接触模型及接触算法进行了研究；利用海洋波浪力学理论,对管柱在修井液中的粘滞阻尼模型进行了分析；结合室内台架实验,建立了修井作业过程中修井工具的钻压-扭矩模型；基于现场上提下放实验,对有限元模型进行了验证。(2)大斜度井修井作业参数敏感性分析：研究了起下钻速度对管柱轴力的影响,结果表明起钻速度增加,管柱承受的轴力也会随之增大；分析了井斜角、造斜率、大钩载荷等因素对管柱轴力和扭矩的影响,并通过百米轴力损失和百米扭矩损失对影响因素进行了量化分析；研究了摩擦系数、管柱壁厚及油套环空间隙对水平井管柱屈曲临界载荷的影响,研究发现增大摩擦系数和减小环空间隙都会增大临界屈曲载荷。(3)大斜度井修井作业工况力学行为模拟研究：分析了上提下放作业过程中,管柱的受力特点,得出了所分析的实钻井管柱上提时接触力要大于下放时接触力,且第一增斜段百米轴力损失最大；对封隔器解封过程进行了研究,比较了大斜度井仿真钩载、实验钩载及直井钩载的关系：对套铣和磨铣作业进行了研究,提出了扶正器和钻铤的安放方案,并对临界钻压进行了分析。在上述研究的基础上,建立了一套大斜度井修井管柱力学有限元二次开发分析模块,它有利于现场工程人员掌握修井管柱有限元分析方法,降低其使用门槛。本文的研究对大斜度井修井作业过程中的管柱组合确定、修井设备选择及各技术参数优化提供了理论指导。
[Abstract]:With the application of large deviated well technology in oil field, the workover condition of large deviated well is becoming more and more complicated. Because of its large inclined angle and long horizontal displacement, it is difficult to transfer axial force and torque of pipe string in workover operation. At the same time, because the diameter of workover string is small and stiffness is low, the risk of overhauling operation is increased. It is very important to correctly understand the stress of workover string in wellbore to improve workover efficiency, ensure workover safety and reduce workover cost. On the basis of previous studies, this paper studies the problems of relatively weak understanding of pipe string mechanics in heavy workover operation from two aspects: experiment and simulation. The model of drilling pressure and torque during workover tool operation is studied with laboratory bench test. The finite element simulation model of pipe string and casing (or shaft wall) is established for heavy workover of large inclination well, and the field experiment is carried out to verify the model. According to the established finite element model, the sensitivity of heavy repair parameters of large deviated wells is studied, the mechanical behavior of rod string under various working conditions is simulated, and the guidance for tubing assembly and drilling pressure range of workover operation is put forward. The main research work is as follows: (1) finite element modeling method for simulating the mechanical behavior of workover string: according to the contact characteristics between workover string and shaft wall, the contact model and contact algorithm between pipe string and shaft wall are studied. Based on the theory of ocean wave mechanics, the viscous damping model of pipe string in workover fluid is analyzed, and the drilling pressure torque model of workover tool during workover operation is established in combination with the laboratory bench experiment. The sensitivity analysis of workover operation parameters of large inclination well is carried out by using finite element model. The influence of drilling speed on axial force of pipe string is studied. The results show that the axial force of pipe string increases with the increase of drilling speed, and the angle of well inclination is analyzed. The influence of factors such as slope making, big hook load on axial force and torque of pipe string is analyzed quantitatively through the loss of 100 meters axial force and 100 meter torque, and the friction coefficient is studied. The influence of string wall thickness and annular clearance on critical buckling load of horizontal well string, It is found that increasing the friction coefficient and decreasing the annulus clearance will increase the critical buckling load. It is concluded that the contact force when lifting the pipe string is greater than the contact force when it is lowered, and the maximum axial force loss of 100 meters in the first inclined section is obtained, and the Packer unsealing process is studied, and the simulated hook load of the large slope well is compared. The relationship between experimental hook load and hook-up load in straight well: the operation of sleeve milling and grinding milling was studied, and the arrangement scheme of centralizer and drill collar was put forward, and the critical drilling pressure was analyzed. On the basis of the above research, a set of finite element secondary development analysis module of workover string mechanics is established, which is helpful for field engineers to master the finite element analysis method of workover string and reduce the threshold of its use. The research in this paper provides theoretical guidance for the determination of tubing string combination selection of workover equipment and optimization of various technical parameters during workover operation in large deviated wells.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE935

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