Patent ID: 7690430

Claim:
A method of withdrawing elongate polymeric casing pipe from a well in sections and through a well head thereof, comprising the activities of: supplying a thread tap adapted to cut internal thread in the casing pipe's wall; twisting the thread tap into the casing pipe's open top until a sufficient threaded engagement is achieved; forcing the thread tap through a retraction stroke such that the casing pipe is drawn out of the well through the well head; at the end of the retraction stroke, if not all of the casing pipe is drawn out of the well then severing the casing pipe into a severed-off section at or near the well head, which produces a new open top for that much of the casing pipe that remains in the well; liberating the thread tap and repeating at will the activities beginning with twisting the thread tap into the casing pipe from the open top thereof; wherein liberating the thread tap comprises breaking up the polymeric casing pipe with a striking object.