Methods of treating a subterranean formation to convert organic matter into producible hydrocarbons

• US 7,631,691 B2
• Filed: 01/25/2008
• Issued: 12/15/2009
• Est. Priority Date: 06/24/2003
• Status: Expired due to Fees

• Current Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation)
• Original Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation)
• Inventors: El-Rabaa, Abdel Wadood M, Kaminsky, Robert D., Thomas, Michele M., Symington, William A., Passey, Quinn, Meurer, William P.
• Primary Examiner(s): Bagnell; David J
• Assistant Examiner(s): Coy; Nicole A
• Application Number:
  US12/011,456
• Publication Number:
  US 20080173443A1
• Time in Patent Office: 690 Days
• Field of Search: 166/248, 166/272.1, 166/272.2, 166/263, 166/279, 166/308
• US Class Current: 166/248
• CPC Class Codes: E21B 43/2401 by means of electricity
• CPC Class Codes: E21B 43/2405 in association with fracturing or crevice forming processes E21B43/247 takes precedence
• CPC Class Codes: E21B 43/26 by forming crevices or fractures

Abstract

Methods are provided that include the steps of providing wells in a formation, establishing one or more fractures in the formation, such that each fracture intersects at least one of the wells, placing electrically conductive material in the fracture, and applying an electric voltage across the fracture and through the material such that sufficient heat is generated by electrical resistivity within the material to heat and/or pyrolyze organic matter in the formation to form producible hydrocarbons.

Claims

1. A method of treating a subterranean formation that contains solid organic matter, said method comprising:

(a) providing one or more wells that penetrate a treatment interval within the subterranean formation;

(b) establishing at least one fracture from at least one of said wells, whereby said fracture intersects at least one of said wells;

(c) placing electrically conductive material in said fracture, wherein said electrically conductive material is comprised of a mixture of at least a first material and a second material, wherein the first material comprises substantially non-electrically conductive cement;

(d) placing two electrodes in contact with the electrically conductive material; and

(e) applying a voltage across the two electrodes causing an electric current to pass through said fracture such that said current passes through at least a portion of said electrically conductive material and sufficient heat is generated by electrical resistivity within said portion of said electrically conductive material to pyrolyze at least a portion of said solid organic matter into producible hydrocarbons.

2. The method of claim 1 wherein said subterranean formation comprises oil shale.

3. The method of claim 2, wherein the second material is an electrically conductive proppant material.

4. The method of claim 2, wherein the second material comprises is an elongated material.

5. The method of claim 4, wherein the second material comprises is a fiber, wirelet, shaving, or platelet.

6. The method of claim 5, wherein the second material is electrically conductive.

7. The method of claim 6, wherein the second material is comprised of a metallic material.

8. The method of claim 4, wherein the elongated material has an average length that is between 5 and 30 times the average grain size of the proppant material.

9. The method of claim 4, wherein the elongated material has an average width that is less than 50 percent of the average grain size of the proppant material.

10. The method of claim 1, wherein the second material is an electrically conductive proppant material.

11. The method of claim 1, wherein said subterranean formation comprises heavy oil or tar sand.

12. A method of treating a heavy oil or tar sand subterranean formation containing hydrocarbons, said method comprising:

(a) providing one or more wells that penetrate a treatment interval within the subterranean formation;

(b) establishing at least one fracture from at least one of said wells, whereby said fracture intersects at least one of said wells;

(c) placing electrically conductive material in said fracture, wherein said electrically conductive material is comprised of a mixture of at least a first material and a second material, wherein the first material comprises cement and the second material comprises an electrically conductive proppant material;

(d) placing two electrodes in contact with the electrically conductive material; and

(e) applying a voltage across the two electrodes causing an electric current to pass through said fracture such that said current passes through at least a portion of said electrically conductive material and sufficient heat is generated by electrical resistivity within said portion of said electrically conductive material to reduce the viscosity of at least a portion of said hydrocarbons.

13. The method of claim 12, wherein the cement is substantially non-electrically conductive.

14. The method of claim 12, wherein the second material comprises an elongated material.

15. The method of claim 14, wherein the second material comprises a fiber, wirelet, shaving, or platelet.

16. The method of claim 15, wherein the second material is electrically conductive.

17. The method of claim 16, wherein the second material is comprised of a metallic material.

18. The method of claim 14, wherein the elongated material has an average length that is between 5 and 30 times the average grain size of the proppant material.

19. The method of claim 14, wherein the elongated material has an average width that is less than 50 percent of the average grain size of the proppant material.

20. A method of producing hydrocarbon fluids, comprising:

heating a subterranean formation that contains organic matter comprised of solid organic matter, heavy oil, tar sands, or combinations thereof, wherein the heating comprises;

(a) providing one or more wells that penetrate a treatment interval within the subterranean formation,

(b) establishing at least one fracture from at least one of said wells, whereby said fracture intersects at least one of said wells;

(c) placing electrically conductive material in said fracture, wherein said electrically conductive material is comprised of a mixture of at least a first material and a second material, wherein the first material comprises a substantially non-electrically conductive cement;

(d) placing two electrodes in contact with the electrically conductive material; and

(e) applying a voltage across the two electrodes causing an electric current to pass through said fracture such that said current passes through at least a portion of said electrically conductive material and sufficient heat is generated by electrical resistivity within said portion of said electrically conductive material to pyrolyze or reduce the viscosity of at least a portion of said organic matter thereby forming producible hydrocarbons; and

producing at least a portion of the producible hydrocarbons to the surface.

21. The method of claim 20, wherein the subterranean formation is an oil shale formation.

22. The method of claim 20, wherein said subterranean formation comprises heavy oil or tar sand.

23. A method of treating a subterranean formation that contains solid organic matter, said method comprising:

(a) providing one or more wells that penetrate a treatment interval within the subterranean formation;

(b) establishing at least one fracture from at least one of said wells, whereby said fracture intersects at least one of said wells;

(c) placing electrically conductive material in said fracture, wherein said electrically conductive material is comprised of a mixture of at least a first material and a second material, wherein the first material is cement and the second material is an electrically conductive proppant material;

(d) placing two electrodes in contact with the electrically conductive material; and

(e) applying a voltage across the two electrodes causing an electric current to pass through said fracture such that said current passes through at least a portion of said electrically conductive material and sufficient heat is generated by electrical resistivity within said portion of said electrically conductive material to pyrolyze at least a portion of said solid organic matter into producible hydrocarbons.

24. The method of claim 23, wherein said subterranean formation comprises oil shale.

25. The method of claim 23, wherein the cement is substantially non-electrically conductive.

26. The method of claim 23, wherein the second material comprises an elongated material.

27. The method of claim 26, wherein the second material is electrically conductive.

28. The method of claim 26, wherein the elongated material has an average length that is between 5 and 30 times the average grain size of the proppant material.

29. The method of claim 26, wherein the elongated material has an average width that is less than 50 percent of the average grain size of the proppant material.

30. The method of claim 23, wherein the second material comprises a fiber, wirelet, shaving, or platelet.

31. The method of claim 23, wherein the second material comprises a metallic material.