表面粗糙度对油套管特殊螺纹密封面性能的影响

Effect of Surface Roughness on Sealing Surface Performance of Premium Connection of Oil Casing

以往对油套管特殊螺纹密封的数值模拟都是在光滑平面的基础上展开的,不能真实反映油管连接时载荷接触状况。运用蒙特卡洛法建立考虑粗糙度的油管密封面接触模型,分析表面粗糙度、接头母扣球面半径、内压载荷对油管密封面性能的影响。结果表明:同一过盈量下,密封面粗糙度越小,平均接触压力越小;母扣球面半径越大,密封面接触长度越长,贴合度越高;随着内压的增加,由于公扣密封接触面上的微凸体与锥面的接触次数逐渐增多,并且在相互接触的情况下,其弹性变形程度逐渐降低,而塑性变形增大,此时因接触长度增大,密封表面具有较好的密封性能。

In the past,the numerical simulation of the premium connection seal of the oil casing was carried out on the basis of the smooth plane,which could not truly reflect the load contact condition during oil pipe connections.The Monte Carlo method was used to establish a contact model of the sealing surface of the tubing considering the roughness,and the effects of surface roughness,spherical radius of the joint female buckle and internal pressure load on the performance of the sealing surface of the tubing were analyzed.The results show that under the same interference,the smaller the roughness of sealing surface,the smaller the average contact pressure.The larger the radius of the spherical surface of the female buckle,the longer the contact length of the sealing surface and the higher the fit.With the increase of internal pressure,the number of contacts between the microconvex body and the cone surface on the contact surface of the buckle seal gradually increases,and in the case of mutual contact,the degree of elastic deformation gradually decreases,while the plastic deformation increases.Due to the increase in the contact length,the sealing surface has good sealing performance.