Backpressure check-valve assembly with unique non-metal construction
Halliburton’s insert float valve is a backpressure check-valve assembly for casing flotation and cementing operations in wells involving moderate temperature and depth.
Installed between the pin and box ends of long or short API 8 RD or buttress-thread casing joints, the insert float valve can be used for differential pressures up to the collapse tolerance of the lightest weight of J-55 casing (in the casing size in which it is run). Because of limited space between the casing box and pin, insert float valves are not offered for premium thread casing.
One or more insert valves can be run in a casing string or in conjunction with a guide shoe. Aluminum construction on these insert float valves permits easy drillouts with a medium-tooth, roller-cone rock bit. (PDC bits should not be used to drill out insert valves.)
Insert float valves have a large flow area and can be readily converted to autofill equipment with the addition of an orifice self-fill unit, which includes a weighted plastic ball and plastic orifice tube. The orifice tube holds the flapper open until the ball is dropped into the casing. Once the ball reaches the ball seat, pressure is applied to shear out the plastic orifice tube, which allows the valve to close. This configuration allows efficient operation in mud systems containing high concentrations of lost-circulation material.