Releasable well tool stopping devices and systems

摘要

A tool stopping device for use in a well flow conductor having a preferably full open bore and an abrupt stop shoulder surrounding the bore and engageable by corresponding stop shoulders of spring biased keys carried on a well tool for stopping the well tool as it moves through the flow conductor to indicate the tool's arrival at the device, the device having lugs remotely actuable from the surface for releasing the keys from engagement with the stop shoulder in the device for movement of the well tool therebeyond. One form of the device is suitable for stopping tools entering from one direction only. Another form of the device is suitable for stopping tools both moving into and out of a well. Either or both types of devices may be used in any quantity to provide known checkpoints in a well system for monitoring the progress of well tools moving therethrough.