| CPC E21B 17/07 (2013.01) | 16 Claims |

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1. A contraction joint, comprising:
an upper tubular member having a bore therethrough;
a mandrel comprising: an upper mandrel sub comprising a port; a lower mandrel; and a mandrel crossover connecting the upper mandrel sub to the lower mandrel, wherein the mandrel is at least partially disposed within the upper tubular member,
wherein the upper tubular member is capable of moving uphole and downhole to change a length of the contraction joint;
a nipple housing connected to the upper tubular member;
a piston housing connected to the nipple housing and the lower mandrel;
a support piston disposed in the piston housing, the support piston being affixed to the upper mandrel sub of the mandrel via at least one piston retaining device,
a lock housing disposed between the upper tubular member and the upper mandrel sub of the mandrel; and
a stroke locking mechanism disposed within the lock housing, the stroke locking mechanism comprising a profile that engages the nipple housing,
wherein, in a locked position, the stroke locking mechanism is supported by the support piston, and the profile of the stroke locking mechanism prevents the nipple housing from moving.
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