压缩式封隔器密封机构的设计与分析

发布时间：2018-02-24 07:29

本文关键词： 封隔器密封性能防突结构力学分析有限元分析　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：水平井分段压裂技术广泛用于储层薄、渗透率低的储层改造,封隔器作为分段压裂管柱中的核心工具,其密封性能的好坏将直接影响采收效率。本文针对橡胶筒的密封性能,对压缩式封隔器的密封机构进行研究。封隔器的核心是密封机构,文章首先对密封胶筒的端面斜角、外径和高度提出了设计依据,对其形状和尺寸进行优化;为避免胶筒端部突出,设计了两种活动式的防突装置;对密封胶筒的常用材料进行了性能对比,选取氢化丁腈橡胶为胶筒材料,为后续有限元分析做准备。接下来对密封胶筒的受力情况进行理论分析,对在已知工作压差下,无防突装置胶筒的接触应力的计算公式进行推导;然后把胶筒的变形分为自由变形、约束变形和稳定变形三个阶段,分别从结构特征和压差两方面入手,对坐封力的计算公式进行推导。由理论分析结果得出,适当增加支撑环直径对可提高胶筒的接触应力有很大帮助。最后对胶筒的密封特性进行有限元分析,由于橡胶筒随载荷的变化是非线性的,需要对其建立合理的橡胶材料本构模型。本文采用的是Yeoh超弹性本构模型,在完成建模、定义材料和确定边界条件等前处理步骤后,重点分析了胶筒的形状尺寸和坐封力的大小对胶筒压缩距、胶筒与套管间接触应力的影响,以及防突措施对胶筒应变和胶筒与套管间接触应力的影响。分析结果表明:胶筒的压缩距和接触应力随坐封力的增加而增大;在采取防突措施后,胶筒的肩部突出更小,产生的压缩距和接触应力更大,可有效提高胶筒的密封性能。
[Abstract]:Horizontal well fracturing technology is widely used in reservoir reconstruction with thin reservoir and low permeability. As the core tool of segmented fracturing string, the sealing performance of Packer will directly affect the recovery efficiency. The sealing mechanism of compression Packer is studied. The sealing mechanism is the core of Packer. Firstly, the design basis for the angle, diameter and height of the end face of the cylinder is put forward, and the shape and size of the Packer are optimized. Two kinds of movable anti-outburst devices were designed in order to avoid sticking out of the end of the rubber tube, and the performance of the common materials of the sealing rubber cylinder was compared, and hydrogenated nitrile butadiene rubber was selected as the cylinder material. Then the stress of the sealant cylinder is analyzed theoretically, and the formula of contact stress of the rubber tube without outburst device is deduced under the known working pressure difference. Then, the deformation of rubber cylinder is divided into three stages: free deformation, restrained deformation and stable deformation. The formula for calculating the seat-seal force is derived from the structural characteristics and pressure difference, respectively. It is helpful to increase the contact stress of the rubber cylinder by increasing the diameter of the supporting ring properly. Finally, the sealing characteristics of the rubber cylinder are analyzed by finite element method, because the rubber cylinder is nonlinear with the change of load. It is necessary to establish a reasonable constitutive model of rubber material. The Yeoh superelastic constitutive model is used in this paper. After the pre-processing steps such as modeling, defining materials and determining boundary conditions are completed, The influence of the shape and size of the rubber cylinder and the size of the sealing force on the compression distance of the rubber cylinder and the contact stress between the cylinder and the casing are analyzed. The results show that the compression distance and contact stress increase with the increase of the sealing force, and the shoulder protruding is smaller after the anti-outburst measures are taken. The compression distance and contact stress are larger, which can effectively improve the sealing performance of rubber cylinder.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE931.2

【参考文献】