Abstract: A gas recovery device utilizes membranes of a gas permeable, liquid impermeable substance to strip gas from gas-containing liquids, such as brine in subterranean geological formations. The device includes a shell defined by perforated outer walls and a plurality of elongated permeation tubes. Only one end of the tubes is attached to a plenum with the tube lumina in fluid communication with the plenum. The remainder of the tubes is not anchored and therefore is free to move. Substantially liquid-free gas is removed from the plenum through a pipe to a remote facility for storage and use. The gas recovery device can be deployed within the casing of a well suspended by the product discharge pipe and immersed in gas-containing brine flowing from a natural geological formation. The brine seeps into the well casing and flows through the perforations to surround the permeation tubes.