| 摘要 |
A tubular coupling comprises a male threaded section 16 and a female threaded section 14. The female threaded section 14 has a shoulder 18 at the base of its thread 20 and the shoulder 18 is engaged by an abutment 22 on the male threaded section 16, when the sections 14 and 16 are fully engaged, to thereby provide a seal. The shoulder 18 is under cut and the abutment 22 is complementarily shaped whereby, upon application of a lateral bending moment to the coupling, a radial force is produced between the shoulder 18 and abutment 22 in order to maintain the seal. There is also provided a sleeve for lining a well wall comprising sleeve sections and tubular couplings for interconnecting the sleeve sections. The sleeve sections may be formed by friction forging a coupling component to each end of a central tubular member (12), wherein the coupling components are preferably components of the tubular coupling outlined above. <IMAGE> |
