Patent ID: 8925632
Filing Date: 2015-01-06
Classification: E21B

Abstract:
1. A method to recover methane gas from an underground hydrate reservoir that has been penetrated by injection and production wells, the method comprising the steps of: a) drilling a saline water injection well proximate the base of the hydrate reservoir; b) drilling a substantially non parallel production well that at some location along its length is within 1 to 10 m from a part of the injection well; c) initially injecting saline water into the production well which creates a depletion chamber between the injection and production wells; d) varying the injection procedure for the saline water, wherein varying the injection procedure includes varying at least one of injection pressure, injection rate, temperature, or salinity, to propagate a depletion chamber in the hydrate formation resulting from hydrate decomposition; and e) extraction of gas and water from the depletion chamber through the production well.