Through-tubing retrievable whipstock system

Abstract

The present invention, in certain embodiments, discloses a whipstock system which is hydraulically settable in a tubular or wellbore and mechanically retrievable. In one aspect it is a 'through-tubing' system. In certain aspects systems according to this invention have a concave to a lower end of which is secured an anchor housing bendable member, movable connection, or with an anchor body therein that is in fluid communication, via a flexible hose within the anchor housing, with a fluid channel running through the concave. An upper end of a mandrel is housed in a recess in the anchor body. The mandrel's lower end may extend out from the anchor housing. A setting slip is disposed below the anchor body within an opening in the anchor housing. A pusher sleeve below the slip is selectively displaced up by a piston below the pusher sleeve to push the slip out from the opening in the anchor housing to set against an interior of a tubular or of a wellbore. Fluid under pressure flows, e.g. from a pump system at the earth's surface, through the concave, through the anchor body, to and through the mandrel, exiting the mandrel beneath the piston to move the piston upwardly, thereby moving the slip out from the housing. Initially a shear pin or shear screw holds the slip in place. The present invention also discloses a retrieval tool for retrieving the whipstock system from a wellbore. The retrieval tool, in one aspect, has a member that is inserted into and held within a corresponding recess in the top of a concave while an opposed portion of the tool abuts a side of the concave opposite the recess to securely grip the concave and the apparatus suspended therefrom for retrieval.