压缩式胶筒结构优化及裸眼密封性能分析

Structurally Optimizing Rubber Cylinder of Compression Packer and Analyzing Its Open-eye Sealing Performance

压缩式封隔器广泛用于油田分层开采工艺,其胶筒的坐封通过高压流体作用在活塞上压缩胶筒或管柱来实现。现场作业发现:压缩式胶筒离载荷端较远,且大多采用单向加载,导致坐封不完全,接触应力与密封性能系数较低。针对上述问题,基于Mooney-Rivlin超弹模型、胶管变形及接触非线性理论,建立压缩式胶筒组有限元计算模型,从内衬套和防肩突结构开展单因素分析,并对其裸眼密封性能进行研究,结果表明:三角形内衬套能有效提高胶筒中部接触应力;金属圆环防突结构能提高胶筒密封性能系数;与常规压缩式封隔器相比,优化后的压缩式封隔器密封性能显著提高;裸眼井壁的不规则程度在一定范围内时,对封隔器的密封性能影响不大。

A compression packer is widely used in an oilfield’s stratified production processes,and the setting of its rubber cylinder is achieved by compressing the rubber cylinder or pipe string through the action of high-pressure fluid on the piston.Field operations find that the rubber cylinder is far from the load end and that the majority of it are loaded in one direction,resulting in incomplete setting and low contact stress and sealing performance coefficient.Due to the above problems,based on the Mooney-Rivlin hyper-elastic model,the hose deformation and contact nonlinear theory,the finite element model for calculating the compression rubber cylinder group was established,and the single factor analysis was carried out from the inner bushing and the anti-shoulder structure,and the open-hole sealing was carried out.The performance is studied,and the results show that:1)the triangular inner bushing can effectively improve the contact stress in the middle of the rubber cylinder;2)the metal ring anti-burst structure can improve the sealing performance coefficient of the rubber cylinder;3)compared with the conventional compression packer,the sealing performance of the optimized compression packer is significantly improved;4)when the irregularity of the open hole wall is within a certain range,the sealing performance of the compression packer is not affected much.