加热电缆填料密封结构及其有限元分析

Packing Sealing Structure of Heating Cable and Its Finite Element Analysis

为实现井口高压力防喷目的,提出了一种适用于加热电缆防喷器的填料密封结构。该填料密封结构中填料环通过压阀压缩实现预安装,起到对腔内流体密封的目的。通过建立填料密封结构理论模型,分析了填料环在压缩变形阶段和流体渗透阶段的力学行为,利用有限元软件建立了填料密封结构的二维轴对称模型,分析填料环在不同压缩载荷和流体压力下的填料环变化规律。结果表明:不同压缩载荷下填料环最大应力应变随压缩载荷的增大而增大,当载荷超过15 MPa时,应变区域开始向下转移;密封面上的接触应力沿着轴向位置基本呈现递减趋势,且随着压缩载荷的增大而增大;随流体渗透载荷的增加,流体逐渐从密封面向上渗透,接触长度不断减小。

A packing sealing structure suitable for heating cable blowout preventers has been proposed as a means of achieving the purpose of high-pressure blowout prevention at the wellhead.The packing ring,which forms part of the packing sealing structure,is pre-installed by compressing the pressure valve.This achieves the purpose of sealing the fluid inside the cavity.Firstly,a theoretical model of the packing seal structure was constructed,and the mechanical behaviour of the packing ring during the compression deformation stage and fluid infiltration stage was analysed.Subsequently,a two-dimensional axisymmetric model of the packing seal structure was constructed using finite element software.Finally,an analysis was conducted to determine the variation law of the packing ring under different compression loads and fluid pressures.The findings indicate that the maximum stress-strain of the packing ring increases with the rise in compression load under varying compression loads.When the load exceeds 15 MPa,the strain region begins to shift downwards.The contact stress on the sealing surface demonstrates a decreasing trend along the axial position,increasing with the increase of compressive load.As the fluid permeation load rises,the fluid gradually penetrates upwards from the sealing surface,and the contact length continuously decreases.