Shearable no go insert for a well lock

摘要

An improved no go shoulder on a well lock which is adapted to lock in a locking notch in a landing nipple in a well in which the lock includes a setting wedge to be moved, after shearing setting shear means, for actuating locking dogs into the locking notch. The no go shoulder is of a shearable material having a shear strength load capacity greater than the shear strength capacity of the setting shear means but having a shear strength capacity less than the shear strength capacity of the landing nipple shoulder whereby the strength of the no go is sufficient to allow the lock to be set but is insufficient to deform the landing nipple shoulder. Preferably, the no go shoulder is a shearable insert positioned in a recess in the lock.