| 摘要 |
<p>The downhole lock assembly comprises a lock mandrel (10) connected to a running tool (11). The running tool holds an inner mandrel (13) located within the lock mandrel (10) in a position which allows lock-out keys (20) of the lock mandrel (10) to remain within the outside diameter of the lock mandrel body (12). Shear pins (34) are adapted on downward jarring against a landing nipple to expand the keys (20) and shear pins (33) are adapted on upward jarring to release the running tool. The running tool has a 'tell-tale' collet (30), connected to it by a shear pin (32), to indicate that the lock mandrel is correctly set in the landing nipple, said collet being adapted when the running tool (11) is released from the lock mandrel (10) after setting the lock to disengage intact from the lock mandrel (10) if the lock-out keys (20) are correctly set and to foul the inner mandrel and shear the shear pin (32) if the lock-out keys are incorrectly set. The inner mandrel (13) is resiliently urged in an upward direction, i.e. in the direction of flow from the well, to actuate the lock-out keys (20) to set the lock, and latch means (22) is provided to hold the inner mandrel in a downward disposition against its resilient means prior to setting the lock.</p> |
