Abstract: A hydrostatic module interlock for a downhole tool including a piston having fingers extending from a body thereof, a piston mandrel telescopically arranged with the piston, and a retaining piston disposed to prevent finger deflection in the first position and allow finger deflection in the second position. A method for actuating an interlocked tool including loading a release configuration to a threshold force, releasing the release configuration, moving a retaining piston out of a first position wherein the retaining piston physically impedes deflection of a finger of a piston, deflecting the finger out of engagement with a piston mandrel telescopically arranged relative to the piston, and moving the piston relative to the piston mandrel. A borehole system including a borehole in a subsurface formation, a string disposed in the borehole, and a hydrostatic module interlock disposed within or as a part of the string.

Abstract: A hydrostatic module interlock for a downhole tool including a piston having fingers extending from a body thereof, a piston mandrel telescopically arranged with the piston, and a retaining piston disposed to prevent finger deflection in the first position and allow finger deflection in the second position. A method for actuating an interlocked tool including loading a release configuration to a threshold force, releasing the release configuration, moving a retaining piston out of a first position wherein the retaining piston physically impedes deflection of a finger of a piston, deflecting the finger out of engagement with a piston mandrel telescopically arranged relative to the piston, and moving the piston relative to the piston mandrel. A borehole system including a borehole in a subsurface formation, a string disposed in the borehole, and a hydrostatic module interlock disposed within or as a part of the string.