WELL TOOL APPARATUS AND METHOD

摘要

A well tool apparatus and method is disclosed for sensing and testing conditions in a well to ascertain if the pipe is stuck at a test location in the well bore. A sensor means is provided for sensing whether the pipe is stuck and a reference means provided for moving the sensor means into a reference position from which movement of the pipe when stressed indicates whether the pipe is stuck at the test location. A time delay is provided during which the reference means moves the sensor means into the reference position after the sensor means is at the test location and wherein the sensor means is in a proper reference position for accurate sensing operation.