| 摘要 |
A one trip method for cleaning an existing string while performing testing on the string allows in the same trip the drilling of additional wellbore. The cleanup equipment is retracted after the testing is completed so that it will not impede the advancement of the drill bit at the lower end of the string. The cleanup tools are typically extend for run in through the string and they can be collapsed by a technique such as dropping a ball to shift a sleeve to disable the piston assembly that holds the cleanup tools extended and allows them to be retracted using a return spring or other source of potential energy. |
