摘要 |
A bridge plug tool is disclosed, for temporarily plugging off a well casing to perform a downhole operation, such as cementing, or acidizing. The tool includes a mandrel having separate thread segments thereon. During running in of the tool, one thread segment engages a set of control members, to keep the mandrel in place and to prevent it from shifting longitudinally. In the set position the control members are disengaged from the mandrel, and the other thread segment engages a set of lock members. Setting weight on the mandrel after engagement with the lock members causes a set of slips and packing elements to engage the casing wall. When the downhole job is finished, the mandrel is rotated to disengage from the lock members and to re-engage the control members. This sequence releases the slips so the tool can be retrieved from the casing, or re-set at another point in the casing. |