Patent ID: 6705404
Filing Date: 2004-03-16
Classification: E21B

Abstract:
A system for enhancing gas recovery from a tubing string extending down a wellbore into a reservoir having diminished pressure, the tubing string accumulating liquid from fluids produced from the reservoir, the system comprising:a packer sealingly engaged in the wellbore for forming an annulus between an exterior of the tubing string and an interior of a casing string above the packer, the annulus being isolated from the reservoir; a source of high pressure gas connected to the annulus so as to allow pressure to continuously build within the annulus; a valve located in a bore of the tubing string adjacent the packer the valve comprising a tubular housing threaded for connection to the tubing string, a tubular valve body housed within a bore of the tubular housing; and a valve stem the valve stem being housed within a bore of the valve body and being axially movable therein between a uphole production position and a downhole lift position to alternately open and block one or more production ports and block and open the one or more unloading ports, respectively; and means for actuating the valve stem from the uphole production position to a downhole lift position, wherein in the uphole production position the one or more production Dolls are opened for fluidly connecting the reservoir to the tubing string above the valve for producing gas from the reservoir and the one or more unloading ports, connecting the annulus to the tubing string, are blocked, and in the downhole lift position the one or more production ports am blocked and the one or more unloading ports are open for releasing thigh pressure gas stored in the annulus into the tubing string above the valve to lift and remove accumulated liquids from the tubing string.