Patent ID: 8757267
Filing Date: 2014-06-24
Classification: E21B

Abstract:
1. A system for enhancing gas recovery from a wellbore extending to a reservoir having diminished pressure, the wellbore having a tubing string therein, a packer and compressed gas for pressurizing a wellbore annulus, the packer being set, above perforations, between a casing string and the tubing string for forming the wellbore annulus thereabove, liquids accumulating in a bore of the tubing string as wellbore gas is produced therethrough to surface, the system comprising: a one-way valve at a bottom of the tubing string for one-way fluid communication from the reservoir to the tubing string; and a pressure-actuated valve, housed in the bore of the tubing string uphole from the one-way valve and forming a production annulus therebetween in fluid communication with the tubing annulus, the pressure-actuated valve comprising: a valve body having a valve bore; inlet ports for fluid communication between the wellbore annulus and the valve bore; outlet ports in the valve body, spaced downhole from the inlet ports, for fluid communication between the valve bore and the production annulus; a plunger axially moveable in the valve bore, uphole from the inlet ports, for alternately a main spring operatively connected to the plunger for normally biasing the plunger downhole to the production position; and a pressure-actuated pilot valve system positioned in the valve bore and in continuous pressure communication with the wellbore annulus, wherein