Method for increasing the recovery of natural gas from a geo- pressured aquifer

摘要

A method of increasing the recovery of natural gas from a geo- pressured aquifer containing water and gas and having a zone of free gas dispersed in water, by providing one or more wells extending from the surface to and completed in the geo-pressured aquifer in said zone and allowing the aquifer to flow water and gas under natural pressure through the well and lowering the pressure in the aquifer sufficiently to allow the gas to be released from solution in the water whereby the gas released will migrate more freely to the well and be produced. Also, any gas-phase saturation in the aquifer and any deposit of gaseous hydrocarbons in the formation in pressure communication with the wells will expand due to lowered aquifer pressure and be encouraged to flow to the wells and be recovered. Preferably, the wells are produced at a high enough rate of production to reduce the existing aquifer pressure in the drainage area of the wells as quickly as possible so that gas may be released from solution in the water and so that gaseous hydrocarbons in the formation may expand and flow to the wells. A high initial flow rate of at least 15, 000 barrels of water per day from each well is necessary to effect the lowering of the aquifer pressure by at least 25% in order to provide the necessary mobility of the gas to obtain the enhanced gas recovery by the present method.