| 摘要 |
A tool for multiple purposes features one ore more dogs (24) that can engage a collar groove or restriction sub in the wellbore. The dogs are extendable through a sleeve (20) biased in opposed directions and are supported from a mandrel (10) . The dogs (24) can retract into mandrel grooves (44, 46, 48) to clear restrictions on the trip into the well. On the way up to a collar that has just been passed, the dogs engage and an upward pull on the mandrel displaces fluid through a restriction to allow enough time to get a meaningful surface signal of the overpull force. Thereafter, the applied force can be reduced as the dogs release at a lower applied force to reduce the slingshot effect . The tool can be inverted and used to keep a constant force on a bottom hole assembly during offshore drilling where a heave compensator is employed.
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