Pressure Cycle Operated Perforating Firing Head

• US 20100206633A1
• Filed: 02/18/2009
• Published: 08/19/2010
• Est. Priority Date: 02/18/2009
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Hales, John H., Moore, Randall S.
• Granted Patent: US 8,006,779 B2
• Time in Patent Office: Days
• US Class Current: 175/4.560
• CPC Class Codes: E21B 43/11852 hydraulically actuated

Abstract

Pressure cycle operated apparatus and methods. A method of actuating a firing head includes the steps of: reciprocably displacing an actuator piston of the firing head, the displacing step including the piston being alternately pressure balanced and unbalanced; and igniting a combustible material in response to the piston displacing step. A method of generating electricity includes: reciprocably displacing a piston, the displacing step including the piston being alternately pressure balanced and unbalanced; and generating electricity in response to the piston displacing step. A firing head includes an actuator piston separating at least two chambers; a check valve which permits one-way flow between the chambers; a flow restrictor which restricts flow between the chambers; a biasing device which biases the piston toward one of the chambers; and a firing pin releasing device which releases a firing pin in response to displacement of the piston.

Claims

1. A method of actuating a firing head in a subterranean well, the method comprising the steps of:

reciprocably displacing an actuator piston of the firing head in the well, the displacing step including the piston being alternately pressure balanced and unbalanced; and

igniting a combustible material in response to the piston displacing step.

2. The method of claim 1, wherein the igniting step further comprises detonating explosives of a perforating gun.

3. The method of claim 1, further comprising the step of incrementally advancing a firing pin releasing device in response to reciprocations of the piston in the piston displacing step.

4. The method of claim 1, wherein the piston separates first and second chambers, and wherein the piston displacing step further comprises applying pressure substantially equally to the first and second chambers, and then relieving the applied pressure from the first chamber at a greater rate than relieving the applied pressure from the second chamber, thereby pressure unbalancing the piston.

5. The method of claim 4, further comprising the step of providing substantially unrestricted two-way fluid communication between the first and second chambers in response to a predetermined number of reciprocations of the piston.

6. The method of claim 4, further comprising the step of opening a valve device in response to a predetermined pressure being applied to the second chamber.

7. The method of claim 4, further comprising the step of pressure balancing a firing pin piston in response to a predetermined number of reciprocations of the actuator piston.

8. A method of generating electricity in a subterranean well, the method comprising the steps of:

reciprocably displacing a piston in the well, the displacing step including the piston being alternately pressure balanced and unbalanced; and

generating electricity in response to the piston displacing step.

9. The method of claim 8, wherein the piston separates first and second chambers, and wherein the piston displacing step further comprises applying pressure substantially equally to the first and second chambers, and then relieving the applied pressure from the first chamber at a greater rate than relieving the applied pressure from the second chamber, thereby pressure unbalancing the piston.

10. The method of claim 8, wherein the piston displacing step further comprises reciprocably displacing a magnet relative to a coil.

11. The method of claim 8, wherein the electricity generating step further comprises charging an electrical storage device.

12. The method of claim 8, further comprising the step of using electricity generated in the generating electricity step to detonate an explosive device.

13. The method of claim 12, wherein the explosive device is detonated in response to a predetermined number of reciprocations of the piston in the piston displacing step.

14. A firing head for detonating explosives in a subterranean well, the firing head comprising:

an actuator piston separating first and second chambers;

a check valve which permits flow from the first chamber to the second chamber, but prevents flow from the second chamber to the first chamber;

a flow restrictor which restricts flow between the first and second chambers;

a biasing device which biases the piston toward the second chamber; and

a firing pin releasing device which releases a firing pin in response to displacement of the piston.

15. The firing head of claim 14, further comprising a firing pin piston, whereby a pressure differential across the firing pin piston displaces the firing pin when the firing pin releasing device releases in response to displacement of the actuator piston.

16. The firing head of claim 14, wherein the second chamber contains a compressible liquid.

17. The firing head of claim 16, wherein the compressible liquid substantially entirely fills the second chamber.

18. The firing head of claim 14, wherein the actuator piston incrementally displaces a release member of the releasing device in response to each of multiple reciprocating displacements of the actuator piston.

19. The firing head of claim 14, further comprising a valve device which permits substantially unrestricted fluid communication between the first and second chambers in response to a predetermined number of displacements of the actuator piston.

20. The firing head of claim 14, further comprising a valve device which opens in response to a predetermined pressure being applied to the second chamber.