CA2495364A1 - Well tool anchor and method of releasing gripping elements - Google Patents

Abstract

A selectively released well tool anchor has a tubular wicker shoe cage and a tubular setting sleeve in sliding assembly over a tubular mandrel. The wicker shoe cage confines a plurality of independent wicker shoes. The tubular setting sleeve has a conical slip face that is loosely meshed with the shoe cage by a plurality of collet fingers extended from the conical slip face into meshed engagement with detents in the shoe cage. The collet fingers are secured within the detents for well run- in by calibrated shear fasteners. Slip faces on the several wicker shoes are aligned with the conical slip face to effect a radial displacement of the wicker shoes by an axial translation of the setting sleeve relative to the shoe cage. However, no relative axial translation may occur until sufficient axial compressive force between the shoe cage and setting sleeve is imposed to shear the calibrated fasteners. For selective release from the well bore, the setting sleeve has a body lock ring assembled to the internal bore of the setting sleeve. The lock ring has internal buttress threads that mesh with external buttress threads on the mandrel at a selected position along the mandrel length. Displacement of the mandrel to engage the mandrel threads with the lock ring threads draws the conical slip face from the wicker shoe slip face thereby releasing the wickers from a penetrated engagement with the well wall.