高温高压井完井封隔器卡瓦抗剪切强度分析

Analysis of Shear Strength of Completion Packer Slip in HPHT Well

卡瓦作为封隔器中重要的组成部分,起支撑封隔器和锁定胶筒的作用。针对坐封后卡瓦的咬入会对套管产生损伤,以及套管剪切力会对卡瓦产生损害等问题,模拟高温高压完井封隔器卡瓦的实际受力情况,建立了简化的完井封隔器卡瓦的力学模型,应用弹性力学理论分析了卡瓦的剪切强度,得到了卡瓦剪切强度的计算方法和卡瓦发生损坏的边界条件;采用ANSYS软件分析了卡瓦咬入套管的深度。研究发现,前4个卡瓦牙基本上承受了整个卡瓦作用力,在同一卡瓦牙上,应力最大值出现在卡瓦牙最顶端部位,且对比不同位置的卡瓦齿,发现相同节点的等效应力逐渐下降。第7个卡瓦齿上所有节点的Mises应力很小,可以忽略不计。

As an important part of packer,the slip is used for supporting packer and confining rubber after anchoring. To problems of the casing may be damaged from the slip biting after packer is set,and the slip will be damaged from the shear force of casing,the simplified model of packer slip in high temperature and high pressure wells is established with the consideration of load applied on the slip. Based on the elastic mechanics,the shear strength of the slip is analyzed,the equations of shear strength and slip damage boundary conditions are derived. Also,the depth of slip biting into the casing is analyzed by using the ANSYS software. The research finds that the first four slip teeth almost bear the whole stress,for the one slip tooth,the maximum stress appears at the top of slip teeth,and equivalent stress of the node is decreased gradually comparing with the different location of slip teeth. The Von Mises stress at the whole nodes of the seven slip tooth is too small to be neglected.