Downhole well casing hanger especially suitable for arctic environment

Claim 1

A downhole well casing hanger apparatus especially suitable for suspending casing in a well located in an Arctic environment, comprising: a. a hanger unit including 1. a tubular body having at least one internal cylindrical surface, 2. annular locking groove means in said cylindrical surface, 3. first anti-rotation means for preventing relative rotation between said hanger body and an inner annular element, and 4. means for suspending the hanger body within an outer well element, and b. a combination landing sub and cement squeeze tool including 1. a tubular body having a first outer annular groove, a second outer annular groove axially spaced from said first groove, an outer cylindrical surface intermediate said first and second grooves, and external right-hand threads around said first groove and said outer cylindrical surface, 2. an annular resilient self-contracting locking spring for selective positioning in said first and second grooves and about said outer cylindrical surface, and 3. a tubular actuator means having internal right-hand threads for cooperation with said external right-hand threads to vary the relative position of said tool body and said actuator means in an axial direction, and second anti-rotation means for cooperation with said first anti-rotation means to prevent relative rotation between said hanger body and said actuator means, whereby when said casing hanger apparatus is assembled with said locking spring in said first groove, said actuator means threadedly engaged with said tool body, and said tool body positioned within said hanger body so that said locking spring is opposite said locking groove means and said first and second anti-rotation means are in cooperative engagement, righthand rotation of said tool body will cause it to move axially with respect to said hanger body and said locking spring to expand outwardly into said locking groove means, thereby locking said tool to said hanger unit.