Patent ID: 7021382
Filing Date: 2006-04-04
Classification: E21B

Abstract:
1. A hydraulic axial force generating tool for applying a force on a structure positioned within a borehole, the hydraulic axial force generating tool comprising: a housing sized to fit within the borehole in which the tool is required to act, the housing having an upper end and a lower end; an outer seal disposed about the housing and selected to create a seal between the housing and the borehole; an inner bore through the housing and sealable to prevent flow from the inner bore out through the lower end; an opening to the inner bore above the seal; a bracing means for maintaining the housing against axial movement in the borehole once the housing is in a selected position within the borehole; a piston mounted in sliding engagement with the housing for axial movement relative to the housing between a neutral position and a driven position, the piston positioned to act in response to a pressure differential establishable across the seal to generate a first pressure in the inner bore and a second pressure in the borehole below the seal and in communication with the lower end to drive the piston axially relative to the housing from the neutral position to the driven position; and a grapple connected to the piston for axial movement therewith.