Method and apparatus for injecting gas into a subterranean formation

摘要

A method and apparatus for injecting gas into a subterranean formation wherein the gas to be injected is mixed with a carrier fluid (e.g. water) at the surface to form a mixture which is then flowed down a wellbore. The mixture is flowed through a downhole separator to separate at least a portion of the gas from the mixture which is then injected into the formation. The carrier fluid and any unseparated gas are then returned to the surface to be separated whereby the carrier fluid can be recycled in the gas injection process.