Chemically-aided gas cap drive

摘要

A recovery of attic oil, from a location within a subterranean reservoir between the top of the reservoir and the uppermost opening into a well encountering the reservoir, is improved by injecting fluid comprising or containing a nitrogen-gas-generating solution arranged to yield heat and gas within the reservoir, keeping the injected fluid static long enough for the reservoir to be heated and gas to migrate upward and then producing fluid in response to a gas cap drive.