US Patent 7556102 High differential shifting tool

Systems and methods for opening and/or closing sliding sleeve valves while preventing significant stress upon and damage to the fluid seals that are disposed between the outer housing and the sleeve member elements of the valve. A shifting tool carries a latching device and a fluid closure portion with sacrificial seals. In operations the shifting tool is secured to the sleeve member with the latching device as the closure portion seals off across the fluid flow port of the sleeve member. The shifting tool is then moved to slide the sleeve member between open and closed positions.