一种套管悬挂器金属密封结构设计与研究

Design and Study on Metal Seal of Casing Mandrel Hanger

针对高温高压下悬挂器橡胶密封件的失效问题,采用316L软金属,设计线型、正弦、椭圆、抛物线4种不同的密封结构,采用ANSYS软件分析套管悬重及不同顶丝压力下的接触压力和接触宽度的变化规律。结果表明:随顶丝压力的增加,线型密封各接触面处的平均接触压力增幅较小,正弦和抛物线型密封各接触面处的平均接触压力起伏式增加,椭圆密封各接触面处的平均接触压力平稳增加,表明采用椭圆型接触面有利于密封的稳定。实验结果表明,该全金属多级等锥椭圆曲面密封结构可靠,能满足油田井口装置140 MPa极限工况的密封要求。

Aiming at the problem of sealing failure of wellhead device in high temperature and ultra-high pressure gas wells,the material selection and sealing mechanism of core shaft casing hanger are studied by using finite element method and indoor test method. Composite metal sealing ring material is put forward. The sealing surface is soft metal with high strength matrix.The sealing is achieved through plastic flow of soft metal and elastic deformation of matrix.The increase of the contact pressure of the linear sealing surface is smaller,while the sinusoidal and parabolic seals are increasing undulate,and the average contact pressure of the elliptical seal increases steadily,indicating that the elliptical contact surface is beneficial to the stability of the seal.The results of theoretical study and laboratory experiment show that the full metal multilevel conical elliptical surface sealing structure is reliable and can meet the sealing requirements of limit working condition under the 140 MPa of the oil field wellhead device.