Abstract: Geopressurized gas (methane) containing aquifers are produced into relatively low pressure reservoirs such as depleted or partially depleted oil and gas reservoirs. Primary production of the methane in the water is effected by exsolvation upon entering the low pressure reservoir and movement through the reservoir to production walls. Enhanced recovery of hydrocarbons remaining in depleted or partially depleted reservoirs results from one or more of (1) the sweeping action of the methane moving through the reservoir, (2) pressure maintenance and water drive associated with injection of the naturally pressured water, and (3) reservoir heating caused by the higher temperature of the injected geopressured water.