基于有限元的井下节流器卡定与密封系统优化设计

发布时间：2018-04-30 21:24

本文选题：活动式节流器 + 有限元　；参考：《西安石油大学》2015年硕士论文

【摘要】：井下节流技术作为油气田大规模、低成本开发过程中的一项新技术,有利于解决油气井生产过程中井筒及地面的诸多技术难题。现场应用最多的是2 7/8″活动式井下节流器,从设计角度而言,该井下节流器可根据需要坐封在任意深度,不易发生窜动且能达到密封效果。但在实际使用过程中由于井下压力较高,节流器卡瓦与油管间的锚定力非常大,同时还存在密封胶筒超弹性材料与油管之间的摩擦问题,由此引起的事故也频频发生。因此本文以2 7/8″活动式井下节流器为对象,将公理设计理论与有限元方法相结合,对该节流器核心部件卡定机构与密封机构进行优化设计过程建模、接触应力分布规律分析和结构优化,主要研究内容包括:(1)对活动式井下节流器结构特征、工作原理进行了分析,研究了卡定机构与油管弹塑性接触有限元理论以及密封胶筒超弹性材料与油管非线性接触问题。(2)采用公理设计理论与方法,对卡定机构与密封胶筒机构的优化设计过程进行了统一建模,从而有效支持优化设计过程关键节点控制及知识获取。(3)在公理设计框架下,建立了卡定系统有限元模型,分析了卡瓦厚度、牙型角等重要参数对接触应力的影响规律,以有效降低接触应力为目标,通过参数优化确定了最优结构方案。(4)以公理化优化设计方法为指导,建立了密封胶筒超弹性材料有限元接触模型,研究了胶筒长度、材料、摩擦系数等重要参数对接触应力的影响规律,通过参数优化进行了密封机构的优化设计。本文为活动式节流器结构优化、性能分析及新型节流器研发提供了理论依据和借鉴。
[Abstract]:Downhole throttling technology, as a new technology in the large-scale and low-cost development of oil and gas fields, is helpful to solve many technical problems of wellbore and surface in the production process of oil and gas wells. The most widely used downhole throttle in the field is 27 / 8 "movable downhole throttle. From the design point of view, the downhole throttle can be sealed at any depth according to the need, so it is not easy to move and can achieve sealing effect. However, due to the high downhole pressure, the anchoring force between the throttle slips and the tubing is very large, and there is the friction problem between the sealant tube super-elastic material and the tubing at the same time, the accidents caused by it occur frequently. Therefore, this paper takes 27 / 8 "movable downhole throttle as an object, combines axiomatic design theory with finite element method, and models the optimal design process of the clamping mechanism and sealing mechanism of the core component of the throttle. The distribution law of contact stress and structure optimization are analyzed. The main research contents include: 1) the structure characteristics and working principle of movable downhole throttle are analyzed. The finite element theory of elastic-plastic contact between the clamping mechanism and tubing and the nonlinear contact problem of sealant tube super-elastic material with tubing are studied. The axiomatic design theory and method are adopted. The optimization design process of the clamping mechanism and the sealing cylinder mechanism is modeled in a unified way, which effectively supports the key node control and knowledge acquisition in the optimization design process. In the framework of axiomatic design, the finite element model of the clamping system is established. The influence of the important parameters such as slip thickness and tooth shape angle on contact stress is analyzed. With the aim of reducing contact stress effectively, the optimal structure scheme is determined through parameter optimization. The axiomatic optimal design method is used as the guide. The finite element contact model of sealant cylinder is established, and the influence of important parameters such as length, material and friction coefficient on contact stress is studied. The optimum design of sealing mechanism is carried out through parameter optimization. This paper provides a theoretical basis and reference for the structure optimization, performance analysis and research and development of a new type of throttle.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE931.2

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