高温高压井完井封隔器卡瓦力学分析及有限元数值模拟

Mechanical Analysis and Finite Element Numerical Simulation of Slips of Completion Packer in HT/HP Wells

针对井底高温高压环境容易造成卡瓦牙变形、断裂、严重损害套管等问题,应用静力学理论建立THT完井封隔器卡瓦力学模型进行力学分析,推导出卡瓦牙咬合时的正应力与剪切应力;利用ANSYS Workbench有限元软件,建立了卡瓦-套管咬合三维有限元模拟模型。结果表明:卡瓦牙应力和套管内壁接触应力沿轴向与周向分布都不均匀,在轴向上靠近加载端应力较大起主要锚定作用,远离加载端应力逐渐减小,几乎不起作用;周向上应力几乎沿几何对称面对称分布,对称面附近是主要咬合区。可针对上述应力分布特点对卡瓦结构进行优化设计。

To solve the deformation,fracture and serious damage problem of slip teeth in HPHT environment, the mechanical model of THT completion packer was established based on the theo- ry of static. Also, the equations of normal stress and shear stress of the slip teeth were deduced based on the above mechanical model of THT packer. And, the 3-D engaging model of the slip- casing was built in ANSYS-Workbench to calculate the mechanical characteristic of the packer teeth. It was found that the stress between slip teeth and casing was not the same along the axial and circumferential. In the axial direction, the stress near to the loading position is the larger than that towards away the loading position,and the teeth next to the load play a main role in ancho- ring. Along the circumferential, stress distributes symmetrically, and the geometric symmetry is the main biting area. According to the finite element analysis, the structure of slip can be opti- mized further.