Patent attributes
A toe valve for use in a wellbore includes: a tubular mandrel; a housing extending along a periphery of the mandrel; couplings for assembly as part of a casing or liner string; and a valve piston. The valve piston is: disposed in an annulus formed between the housing and the mandrel, movable between an open position and a closed position, and disposed between a valve port of the housing and a valve port of the mandrel in the closed position. The toe valve further includes: an atmospheric chamber for facilitating movement of the valve piston to the open position; a vent port formed through the housing and in fluid communication with the atmospheric chamber; and a flow control device disposed in the vent port and operable to prevent fluid flow from the wellbore into the atmospheric chamber and allow fluid flow from the atmospheric chamber into the wellbore.
