Patent ID: 8167048

Claim:
A casing valve for use in a well in combination with a shifting tool and a casing string, the well having a wellbore, the wellbore having a target completion interval, the casing valve being positioned in and attached to the casing string between casing members, the casing valve being placed proximate the target completion interval, the wellbore forming an annulus about at least part of the casing valve, the annulus being filled with cement, the cement substantially blocking the casing valve from the wellbore, the valve comprising: a body having a plurality of ports, each port having an area; a shifting member within the body having a solid exterior surface, a distal end, and an interior profile for engagement by the shifting tool such that movement of the shifting tool moves the shifting member between a first position adjacent the ports, such that the ports are closed, and a second position non-adjacent the ports, such that the shifting member distal end is above the ports and the ports are open, the shifting member having a bore, the bore having a cross-sectional area, the combined areas of the ports being not less than 80 percent of the bore cross-sectional area; and a plurality of resilient sealing members, at least one sealing member being positioned above and at least one below the ports when the shifting member is in the first position.