Internally pressurized perforating gun

Patent metadata

Field	Value
Publication number	US-9388673-B2
Application number	US-201113294274-A
Country	US
Kind code	B2
Filing date	Nov 11, 2011
Priority date	Nov 11, 2011
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A technique facilitates a perforation operation. A perforating gun carrier is combined with a pressure enhancement mechanism. The pressure enhancement mechanism provides a controlled increase in pressure within the perforating gun carrier as the perforating gun carrier is delivered into a higher pressure environment. The increase in internal pressure counters the buildup of a pressure differential to the degree desired for a given perforating gun carrier.

First claim

What is claimed is:

1. A method for facilitating a perforation operation in a wellbore, comprising:
preparing a perforating gun carrier string with a perforating gun carrier;
conveying the perforating gun carrier downhole into a wellbore; and
selectively and periodically increasing the pressure within the perforating gun carrier via a pressure enhancement mechanism, carried by the perforating gun string, as the perforating gun carrier is moved downhole through the wellbore.

2. The method as recited in claim 1 , further comprising detonating perforating charges to create perforations in a surrounding formation once the perforating gun carrier has been conveyed to a desired perforating region.

3. The method as recited in claim 2 , wherein increasing comprises increasing the pressure to a level sufficient to reduce a detrimental pressure pulse otherwise resulting from inflow of well fluid into the perforating gun carrier following detonation of the perforating charges.

4. The method as recited in claim 1 , wherein increasing comprises increasing pressure within the perforating gun carrier to a level above the external pressure acting on the perforating gun carrier.

5. The method as recited in claim 1 , wherein increasing comprises increasing the pressure with an internal gas generator.

6. The method as recited in claim 1 , wherein increasing comprises increasing the pressure via the release of compressed gas from a chamber proximate the perforating gun carrier.

7. The method of claim 1 , wherein increasing comprises increasing the pressure via activation of a subcritical fluid at downhole temperature.

8. A method for perforating, comprising:
determining a collapse resistance of a perforating gun carrier;
conveying the perforating gun carrier downhole into a wellbore to a desired perforation location;
selectively and in discrete increments_increasing pressure within the perforating gun carrier while in the wellbore and prior to reaching the desired perforation location to enhance the collapse resistance; and
perforating a formation surrounding the perforating gun carrier.

9. The method as recited in claim 8 , wherein increasing pressure comprises utilizing a pressure enhancement mechanism to release a gas to an interior of the perforating gun carrier.

10. The method as recited in claim 9 , wherein increasing pressure comprises utilizing an internal gas generator.

11. The method as recited in claim 9 , wherein increasing pressure comprises increasing pressure via release of compressed gas from a cooperating chamber.

12. The method as recited in claim 9 , wherein increasing pressure comprises increasing the pressure to a level sufficient to eliminate detrimental pressure pulse effects due to flow back of fluid into the perforating gun carrier following perforating.

13. The method as recited in claim 9 , wherein increasing pressure comprises increasing pressure continuously as the perforating gun carrier is moved downhole.

14. The method of claim 8 , wherein increasing comprises increasing the pressure via activation of a subcritical fluid at downhole temperature.

15. A system to facilitate perforating, comprising:
a perforating gun assembly having a perforating gun carrier and a plurality of perforating gun charges; and
a pressure enhancement mechanism coupled to the perforating gun carrier to selectively release gas into an interior of the perforating gun carrier so as to provide a controlled increase in pressure as the perforating gun carrier is delivered into a higher pressure environment, wherein the pressure enhancement mechanism comprises a subcritical fluid activatable at downhole temperature, wherein increasing comprises continuously increasing the pressure.

16. The system as recited in claim 15 , wherein the pressure enhancement mechanism comprises a propellant charge.

17. The system as recited in claim 15 , wherein the pressure enhancement mechanism comprises an adjacent chamber filled with the gas under pressure.

Assignees

• Grove Brenden M
• Harvey Jeremy P
• Schlumberger Technology Corp

Inventors

• Grove Brenden M
• Harvey Jeremy P

Classifications

• E21B43/11852 Primary

  hydraulically actuated · CPC title

• E21B43/116

  Gun or shaped-charge perforators · CPC title