Steam injection method and apparatus for recovery of oil

• US 4,372,386 A
• Filed: 02/20/1981
• Issued: 02/08/1983
• Est. Priority Date: 02/20/1981
• Status: Expired due to Fees

• Current Assignee: Craig A. Rhoades, Thomas Meeks
• Original Assignee: Craig A. Rhoades, Thomas Meeks
• Inventors: Meeks, Thomas, Rhoades, Craig A.
• Primary Examiner(s): Novosad, Stephen J.
• Assistant Examiner(s): Suchfield, George A.
• Application Number:
  US06/236,447
• Time in Patent Office: 718 Days
• Field of Search: 166/57, 166/59, 166/300, 166/302, 166/303, 166/272, 60/641.2, 60/641.3, 60/641.8, 165/45
• US Class Current: 166/300
• CPC Class Codes: C09K 8/592 Compositions used in combination with generated heat, e.g. by steam injection
• CPC Class Codes: E21B 43/16 Enhanced recovery methods for obtaining hydrocarbons
• CPC Class Codes: E21B 43/164 Injecting CO2 or carbonated water in combination with organic material C09K8/594
• CPC Class Codes: E21B 43/24 using heat, e.g. steam injection
• CPC Class Codes: F24T 10/20 using underground water as working fluid; using working fluid injected directly into the ground, e.g. using injection wells and recovery wells
• CPC Class Codes: Y02E 10/10 Geothermal energy

Abstract

A method and apparatus for recovering oil from an oil bearing formation utilizing steam injected into the formation. A working fluid is heated at the surface to produce a reversible, chemical reaction, particularly a reforming reaction in a reforming/methanation reaction cycle. The products of the reforming reaction are transported at near ambient temperatures to a downhole heat exchanger through which water is circulated. There a catalyst triggers the methanation reaction, liberating heat energy to convert the water to steam. The products of the methanation reaction are recirculated to the surface to repeat the cycle. In one embodiment the products of the methanation reaction are injected into the formation along with the steam. Various catalysts, and various systems for heating the working fluid are disclosed.

Claims

1. A method for generating heat to produce steam for injection into an oil bearing formation penetrated by a borehole, said method comprising:

selecting a working fluid from that class of fluids having first components adapted to undergo an endothermic first reaction upon subjection to reaction heat energy to form second components, wherein said second components are adapted to undergo a reverse, exothermic second reaction to form said first components and release substantially all of said reaction heat energy;

applying said reaction heat energy to said first components to form said second components;

conveying said second components down said borehole and inducing said second reaction to release substantially all of said reaction heat energy and form said first components;

conveying water down said borehole into heat exchange relation to said first components to cool said first components and utilize said reaction heat energy to convert said water to steam; and

,

injecting said steam into said formation.

2. A method according to claim 1 wherein said first components and said steam in said borehole are constrained against intermixture, and said first components are conveyed out of said borehole for reuse in said method.

3. A method according to claim 1 wherein said first components are circulated in heat exchange relation to steam from a geothermal well thereby to derive said reaction heat energy to induce said first reaction.

4. A method according to claim 1 wherein said first reaction is a reforming reaction of first components comprising carbon dioxide and methane to form said second components comprising carbon monoxide and hydrogen, and said second reaction is a methanation reaction of said second components to form said first components.

5. A method according to claim 4 wherein said first components formed by said methanation reaction are injected into said formation with said steam.

6. A method according to claim 4 wherein a nickel catalyst is employed to induce said second reaction.

7. Apparatus for generating heat to produce steam for injection into an oil bearing formation penetrated by a borehole, said apparatus comprising:

container means;

a working fluid in said container means, said working fluid comprising first components adapted to undergo an endothermic first reaction upon subjection to reaction heat energy to form second components, said second components being adapted to undergo a reverse, exothermic second reaction upon subjection to catalytic means to form said first components and release said reaction heat energy;

first heat exchanger means for supplying said reaction heat energy to said first components to form said second components;

second heat exchanger means for location in said borehole and including a first portion having catalytic means, an inlet for receiving said second components, and outlet means for discharging said first components subsequent said exothermic second reaction, said second heat exchanger means further including a second portion having an inlet for receiving water and an outlet for discharging steam into said borehole, said second portion being located in heat exchange relation to said first portion for conversion of said water to steam by said reaction heat energy;

first conduit means connected to said first heat exchanger means and to said inlet of said first portion of said second heat exchanger means for conveying said second components to said second heat exchanger;

water supply means; and

second conduit means connected to said water supply means and to said inlet of said second portion of said second heat exchanger means.

8. Apparatus according to claim 7 and including third conduit means connected to said outlet of said second heat exchanger and to said container means for conveying the formed said first components back to said container means.

9. Apparatus according to claim 7 wherein said outlet of said first portion of said second heat exchanger means is arranged to discharge into said borehole with said steam.

10. Apparatus according to claim 7 wherein said first heat exchanger means includes a fuel burning boiler.

11. Apparatus according to claim 10 wherein said boiler is coupled to a hydrogen generating means.

12. Apparatus according to claim 7 wherein said first heat exchanger means includes means for coupling said first heat exchanger means to a geothermal well for deriving said reaction heat energy.

13. Apparatus for generating heat to produce steam for injection into an oil bearing formation penetrated by a borehole, said apparatus comprising:

methanation reaction means slidably insertable within said borehole and including a reactor portion having a methanation catalyst for catalytically promoting a methanation reaction of carbon monoxide and hydrogen to form carbon dioxide and methane, accompanied by the release of reaction heat energy, and further including a heat exchanger portion adapted to receive water and directly exposed to said reaction heat energy for conversion of said water into steam by said reaction heat energy including means for discharging said steam into said borehole, said means for discharging said steam being coupled to said heat exchanger portion;

reforming reactor means for surface location, and adapted to heat carbon dioxide and methane to reform carbon monoxide and hydrogen;

supply means for conveying carbon dioxide and methane to said reforming reaction means; and

water supply means coupled to said heat exchanger portion.

14. Apparatus according to claim 13 and including conduit means for conveying carbon dioxide and methane from said methanation reactor portion to said supply means.

15. Apparatus according to claim 13 wherein said heat exchanger portion includes means defining multiple pass paths for said water to flow adjacent said reactor portion.