Patent ID: 6907926

Claim:
A valve for enhancing the production of gas from a tubing string extending down a wellbore to a reservoir having diminished pressure, the wellbore having an annulus isolated from the reservoir charged with a continuous flow of high pressure gas and a plunger lift system, the valve comprising: a tubular housing having a bore, the housing being connected to the tubing string and having an upper production port fluidly connected to the tubing string above the valve, a lower production port fluidly connected to the reservoir below the valve, and an unloading port fluidly connecting the isolated annulus to the tubing string above the valve; and a valve stem having an uphole and a downhole piston, housed within the valve housing and axially moveable therein between a first uphole production position wherein the uphole piston blocks the unloading port, the upper and lower production ports are fluidly connected and the downhole piston opens the reservoir to the lower production port for producing gas therethrough, and a second downhole lift position wherein the downhole piston blocks the reservoir from the lower production port and the uphole piston opens the unloading port to permit the charge of high pressure gas in the annulus to pass into the tubing string, for enhancing the production of gas in the tubing string above the unloading port.