| 摘要 |
<p>A casing running tool (56) is provided having both axial and circumferentially tapered elements (76). In certain embodiments, the casing running tool (56) comprises cam structures (76) that are circumferentially tapered so as to allow an applied torque to engage and disengage the casing running tool (56) with a casing (22) or liner (14). In embodiments, the circumferential taper of the cam structures (76) allows a mandrel (58) or rollers (90) disposed between the mandrel (58) and cam structures (76) to apply radial force to corresponding shoe structures (78) which in turn engage or disengage the casing (22) or liner (14). The cam structures (76) may also exhibit an axial taper to allow for a self-energized fail-sage operation of the casing running tool (56).</p> |
