扭转载荷对压裂用封隔器胶筒密封性能的影响

Influence of Torsional Load on Sealing Performance of Compressed Packer Rubber

利用有限元分析软件建立封隔器胶筒模型,分析单一轴向载荷和轴向、扭转载荷共同作用下,胶筒与套管之间的接触应力及其沿轴向的分布规律,最大接触应力随胶筒端面角、子厚度、筒高3个结构参数和摩擦因数的变化,以及施加不同扭转载荷时对胶筒密封性能的影响。研究结果表明:在单一轴向载荷作用下,最大接触应力随倾斜角度增大先减小后增大,随子厚度的增加先增加后减小,随筒高的增加而减小,随摩擦因数增大先减小后增大;施加扭转载荷后,不同端面角、子厚度、筒高下胶筒的最大接触应力整体降低且波动较大,随摩擦因数增大胶筒接触面之间的摩擦力增大,加速了胶筒磨损和老化;不同扭转载荷作用下胶筒最大接触应力值波动较大,导致密封性能不稳定。因此,扭转载荷使得胶筒密封性降低,导致最大接触应力波动较大,使胶筒的密封性能存在不稳定性。

The rubber model of packer was established by the finite element analysis software.The contact stress between rubber and casing and its axial distribution,the change of maximum contact stress with the structural parameters including the inclination angle of the rubber,the sub-thickness,the rubber height and the friction coefficient,and the effect of different torsion loads on the sealing performance of the rubber tube were analyzed under the single axial load and the combined action of axial and torsional loads.The results show that under the single axial load,the maximum contact stress is decreased firstly and then increased with the increasing of the angle,is increased firstly and then decreased with the increasing of sub-thickness,is decreased with the increasing of rubber height,and is decreased firstly and then increased with the increasing of friction coefficient.After applying torsional load,the maximum contact stress of the rubber with different sub-thickness,inclination angle and height is reduced and has a larger fluctuation,and the friction between the contact surfaces of the rubber tube is increased with the increasing of friction coefficient,which accelerates the wear and aging of the rubber tube.The maximum contact stress of the rubber tube fluctuates greatly under different torsion loads,which leads to the unstable sealing performance.Therefore,the torsional load reduces the sealing performance of the rubber tube,results in a greater fluctuation of the maximum contact stress,and increases the instability of the sealing performance of the rubber tube.