Method of natural gas production

• US 6,973,968 B2
• Filed: 07/15/2004
• Issued: 12/13/2005
• Est. Priority Date: 07/22/2003
• Status: Active Grant

• Current Assignee: Precision Combustion, Inc.
• Original Assignee: Precision Combustion, Inc.
• Inventors: Pfefferle, William C.
• Primary Examiner(s): Walker, Zakiya
• Application Number:
  US10/891,548
• Publication Number:
  US 20050016725A1
• Time in Patent Office: 516 Days
• Field of Search: 166256-258, 166260-262, 166/272.1, 166/272.6, 166/275, 166/300
• US Class Current: 166/260
• CPC Class Codes: E21B 41/0064 Carbon dioxide sequestration storing fluids in porous layers B65G5/005
• CPC Class Codes: E21B 41/0099 specially adapted for drilling for or production of natural hydrate or clathrate gas reservoirs; Drilling through or monitoring of formations containing gas hydrates or clathrates
• CPC Class Codes: E21B 43/243 Combustion in situ
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

A method and system for dissociating methane hydrate deposits in-situ is provided wherein an oxidizer fluid and a supply of fuel, both at a pressure higher than that of the methane hydrate deposit, are supplied and delivered to the methane hydrate deposit. The fuel is combusted downhole by reacting it with the oxidizer fluid to provide combustion products. The combustion products are placed in contact with a diluent fluid to produce a heated product fluid. The heated product fluid is injected into the methane hydrate deposit whereby methane is dissociated from the methane hydrate and made available for extraction. In addition, carbon dioxide may be made available to promote the formation of carbon dioxide hydrates from the liberated methane hydrate water.

Claims

1. A method of dissociating methane hydrate deposits in-situ comprising:

a) providing a supply of an oxidizer fluid at a pressure higher than that of the methane hydrate deposit;

b) providing a supply of fuel at a pressure higher than that of the methane hydrate deposit;

c) combusting the fuel downhole by reacting it with the oxidizer fluid to provide combustion products wherein the fuel is reacred by gas phase flame combustion;

d) contacting the combustion products with a diluent fluid to produce a heated product fluid; and

e) bringing the heated product fluid into contact with the methane hydrate deposit.

2. A method of dissociating methane hydrate deposits in-situ, comprising:

a) providing a supply of oxygen at a pressure higher than that of the methane hydrate deposit;

b) providing a supply of carbon dioxide at a pressure higher than that of the methane hydrate deposit;

c) mixing oxygen with at least a potion of the carbon dioxide to form an oxidizer admixture;

d) providing a fuel;

e) reacting the fuel with the oxidizer admixture downhole to form a heat of reaction and hot combustion products containing carbon dioxide wherein the fuel is reacted by gas phase flame combustion; and

f) contacting the combustion products with the methane hydrate deposits, whereby methane hydrate is dissociated liberating methane.