METHOD FOR THERMAL GASEOUS HYDRATE FIELD DEVELOPMENT Russian patent published in 2007 - IPC E21B43/24 

FIELD: enhanced recovery methods for obtaining hydrocarbons using heat.

SUBSTANCE: method involves penetrating gaseous hydrate field with at least one branched well crossing reservoirs, wherein the branched well has horizontal bores; creating heat flow in underlaying reservoir and producing hydrocarbons from gaseous hydrate reservoir. In the case of field with underlaying natural or artificial hydrocarbon reservoir development horizontal bore of branched well is arranged in underlaying reservoir and provided with section having perforation orifices formed in inlet part thereof. At least one rising section of the well has a number of multilateral perforated horizontal branches located in gaseous hydrate reservoir. Heat flow is formed by in-situ combustion initiation and fire front maintenance in underlaying reservoir due to oxidizer supply through hole clearance defined by well tubing and production string and through perforation orifices formed in inlet part of horizontal section. The section has length selected to provide heating of gas-water mixture formed as a result of gaseous hydrate decomposition up to temperature, which prevents secondary gaseous hydrate creation during gas-water mixture movement within interval between underlaying reservoir roof and well head. Hydrocarbons, namely natural gas with water, are produced via multilateral perforated horizontal branches.

EFFECT: increased efficiency due to extended area of thermal treatment and, accordingly, gaseous hydrate decomposition volume, as well as decreased costs due to possibility to use unprofitable reserves of underlaying oil and/or gas rims.

3 cl, 1 ex, 3 dwg