Patent ID: 7100695
Filing Date: 2006-09-05
Classification: E21B

Abstract:
1. A method of recovering natural gas from a well in a multiple phase gas recovery cycle, the well having a casing chamber defined by a casing within the well, a production chamber within a production tubing inserted into the casing chamber and a lift chamber defined by a lift tube inserted within the production chamber, the well also including a one-way valve separating the production chamber from the casing chamber; the gas recovery cycle including a three chamber evacuation phase in which a relatively low pressure is applied within the casing chamber, production chamber and lift chamber to cause the relatively low pressure to augment natural earth formation pressure and flow more liquid and gas into the casing chamber than would flow only from the natural formation pressure, a liquid capture phase in which relatively high pressure gas is applied to the casing chamber to move liquid within the casing chamber through the one-way valve into the production chamber, and a liquid removal phase in which relatively high pressure gas is applied to the production chamber to close the one-way valve and to isolate the production chamber from the casing chamber and to lift liquid isolated in the production chamber up the lift chamber, and a liquid reduction phase executed after the three chamber evacuation phase and before the liquid capture phase by: applying relatively high pressure within the production chamber to close the one-way valve and to isolate the production chamber from the casing chamber and to lift the liquid accumulated within the production chamber during the three chamber evacuation phase out of the well through the lift chamber; while maintaining the relatively low pressure within the casing chamber.