Electrofracturing formations

Patent metadata

Field	Value
Publication number	US-9243487-B2
Application number	US-201313852680-A
Country	US
Kind code	B2
Filing date	Mar 28, 2013
Priority date	Mar 29, 2012
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

A method is provided to produce hydrocarbons from a formation, the method includes the steps of: placing a pair of electrodes within a formation; applying differential voltages between pairs of electrodes wherein the voltage differences between the electrodes is greater than at least 10,000 volts; and producing hydrocarbons from the formation or an adjacent formation wherein the formation has an initial permeability of less than ten millidarcy. The invention also includes an apparatus effective to release pulses of electrical energy into the formation as this frequency and voltage at least until the formation has reached a point where the electrical potential arcs from one electrode to at least one other electrode.

First claim

What is claimed is:

1. A method to produce hydrocarbons from a formation, the method comprising the steps of:
placing a pair of electrodes within a formation;
applying differential voltages between pairs of electrodes wherein the voltage differences between the electrodes is greater than at least 10,000 volts; and
producing hydrocarbons from the formation or an adjacent formation wherein the formation has an initial permeability of less than ten millidarcy, and wherein as a result of the application of the differential voltage, effective permeability of a formation is increased by between 10 and 10,000 percent, where the effective permeability is defined as an average permeability in a volume between the electrodes, where the volume between the electrodes is defined as the volume within a cylinder having a diameter equal to the length of the electrodes, around a line connecting the centers of the electrodes.

2. The method of claim 1 wherein the differential voltages between the electrodes causes at least a portion of the formation between the electrodes to vaporize.

3. The method of claim 1 wherein the electrodes are moved to different positions within two wellbores and pulses of differential voltages between the pairs of electrodes are repeated.

4. The method of claim 3 wherein the two wellbores are essentially parallel.

5. The method of claim 4 wherein the two wellbores are separated by a distance of between 30 and 90 meters.

6. The method of claim 3 wherein at least a section of both of the wellbores is essentially horizontal within the formation.

7. The method of claim 3 wherein a line between the two electrodes is perpendicular to a plane of natural fractures within the formation.

8. The method of claim 3 wherein a line between the two electrodes is in a direction of the minimum stress within the formation.

9. The method of claim 1 wherein between 10 −6 and 10 −4 of the mineral mass is removed from the formation between the electrodes, where the mass between the electrodes is defined as the mass within a cylinder having a diameter equal to the length of the electrodes, around a line connecting the centers of the electrodes.

10. The method of claim 1 wherein the formation, prior to application of the pulses of differential voltage has a permeability of between 0.00001 millidarcys and 0.001 millidarcys.

11. The method of claim 1 wherein the electrodes comprise electrically conductive propants within hydraulically formed fractures.

12. The method of claim 11 wherein the hydraulically formed fractures extend from different positions along a horizontal well.

13. The method of claim 11 wherein the hydraulically formed fractures extend from different wellbores.

14. The method of claim 11 wherein the hydraulic fractures are parallel.

15. The method of claim 11 wherein the hydraulic fractures are located in essentially the same vertical plane.

16. The method of claim 1 wherein the voltage differences between the electrodes is greater than at least 100,000 volts.

17. The method of claim 1 wherein the differential voltages are applied in a plurality of pulses that are less than 500 nanoseconds in duration.

18. The method of claim 1 wherein the hydrocarbons produced consist essentially of natural gas.

Assignees

• Shell Oil Co

Inventors

• Geilikman Mikhail Boris
• Karanikas John Michael
• Khodaverdian Mohamad Fereydoon
• Ocampos Ernesto Rafael Fonseca
• Wong Sau-Wai

Classifications

• E21C37/18

  by electricity · CPC title

• E21B43/267 Primary

  reinforcing fractures by propping · CPC title

• E21B43/26 Primary

  by forming crevices or fractures · CPC title

• E21B43/16 Primary

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• E21B43/2405

  in association with fracturing or crevice forming processes (E21B43/247 takes precedence) · CPC title