LOCKING ASSEMBLY FOR MECHANICALLY SET PACKER

摘要

A lock assembly for a mechanically set packer for deep deployments is described. The lock housing wall has at least one bore for a rod piston that is selectively actuated when wellbore hydrostatic is allowed to reach on side of the piston. Movement of the piston, after breaking a shear pin, allows a c-ring to spring outwardly and out of a locking groove in the mandrel so that the mandrel can be string manipulated with respect to the housing to set the packer. Once unlocked the lock assembly remains defeated. The piston can be optionally exposed to hydrostatic and will unlock at a given depth without manipulation of the wellbore annulus pressure. Other mechanisms to admit wellbore hydrostatic to move the piston or to move the piston in general by other techniques are described.