Dual aquafer electrical heating of subsurface hydrocarbons

• US 4,612,988 A
• Filed: 06/24/1985
• Issued: 09/23/1986
• Est. Priority Date: 06/24/1985
• Status: Expired due to Fees

• Current Assignee: Atlantic Richfield Company (BP PLC)
• Original Assignee: Atlantic Richfield Company (BP PLC)
• Inventors: Segalman, Daniel J.
• Primary Examiner(s): NOVOSAD, STEPHEN
• Application Number:
  US06/747,752
• Time in Patent Office: 456 Days
• Field of Search: 166/248, 166/60, 166/269, 166/258, 166/65.1, 166/268, 219/415, 219/417
• US Class Current: 166/248
• CPC Class Codes: E21B 36/04 using electrical heaters
• CPC Class Codes: E21B 43/2401 by means of electricity

Abstract

Electrical current is caused to flow between an electrode well located in an aquafer above viscous hydrocarbon-bearing formation and an electrode well located in an aquafer below the hydrocarbon-bearing formation. The electrical current thereby tends to spread out in a broad plate-like configuration from each electrode well. This increases the area of the hydrocarbon-bearing formation through which current is flowed, thereby extending the region which is heated by electrical dissapation. The nature of the aquafers and their location eases and resolves much of the adverse vaporization and pressure buildup that occurs in other systems. This also allows water to be readily injected to into or produced from the electrode wells to further control vaporization and pressure buildup without adversely affecting gravity drainage, other drive mechanisms or injection programs operating within the hydrocarbon-bearing formation. In addition, this enables the electrode wells to be used in a more continuous manner.

Claims

1. A method of electrically heating a viscous hydrocarbon-bearing subsurface formation comprising:

a. applying an electric voltage to a first electrode well extending into a subsurface first aquafer, said first aquafer containing flowable mobile water and having sufficiently high permeability to permit water to be flowed into and out of said first aquafer, said first aquafer extending laterally more than 100 feet from said first electrode well in at least one direction and overlaying said viscous hydrocarbon-bearing subsurface formation;

b. applying an electric voltage to a second electrode well extending into a subsurface second aquafer, said second aquafer containing flowable mobile water and having sufficiently high permeability to permit water to be flowed into and out of said second aquafer, said second aquafer extending laterally more than 100 feet from said second electrode well in at least one direction and underlaying said viscous hydrocarbon-bearing subsurface formation, and

c. causing electric current to flow between said first and second electrode wells and through said viscous hydrocarbon subsurface formation.

2. The method of claim 1 wherein simultaneously with steps "a" and "b", water is injected into one of said first and second electrode wells.

3. The method of claim 2 wherein simultaneously with steps "a" and "b", water is produced from the other of of said first and second electrode wells.

4. The method of claim 1 wherein simultaneously with steps "a" and "b", water is produced from one of said first and second electrode wells.

5. The method of claim 1 wherein simultaneously with steps "a" and "b", water is produced from both of said first and second electrode wells.

6. The method of claim 1 wherein simultaneously with steps "a" and "b", water is injected into both of said first and second electrode wells.