Encapsulant providing structural support for explosives

• US 6,520,258 B1
• Filed: 07/21/2000
• Issued: 02/18/2003
• Est. Priority Date: 07/22/1999
• Status: Expired due to Term

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Grove, Brenden M., Yang, Wenbo, Behrmann, Lawrence A., Fayard, Alfredo, Markel, Daniel C.
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): Dougherty, Jennifer R.
• Application Number:
  US09/621,159
• Time in Patent Office: 942 Days
• Field of Search: 166/55, 166/63, 166/247, 175/4.5, 175/4.6, 102/306, 102/310, 102/312
• US Class Current: 166/297
• CPC Class Codes: E21B 43/117 Shaped-charge perforators E21B43/118 takes precedence
• CPC Class Codes: E21B 43/1195 Replacement of drilling mud; decrease of undesirable shock waves
• CPC Class Codes: F42B 1/02 Shaped or hollow charges blasting cartridges with cavities in the charge F42B3/08; oil winning using shaped-charge perforators E21B43/116
• CPC Class Codes: F42B 1/024 provided with embedded bodies of inert material
• CPC Class Codes: F42B 3/02 adapted to be united into assemblies
• CPC Class Codes: F42D 5/045 Detonation-wave absorbing or damping means

Abstract

An apparatus and method is provided to provide structural support for explosives (e.g., shaped charges) in a tool (e.g., a perforating gun). An encapsulant surrounds at least portions of the explosives to provide structural support for the explosives. The encapsulant contains a porous material, such as porous cement or polymer.

Claims

1. A perforating gun comprising:

one or more shaped charges; and

an encapsulant surrounding the one or more shaped charges to provide structural support for the shaped charges,

wherein the encapsulant comprises cement.

2. The perforating gun of claim 1, further comprising a sleeve around at least a part of the encapsulant.

3. The perforating gun of claim 1, further comprising a support layer around at least a part of the encapsulant.

4. The perforating gun of claim 1, wherein the shaped charges are arranged in a phased pattern.

5. The perforating gun of claim 1, wherein the cement comprises porous cement.

6. The perforating gun of claim 5, wherein the porous cement comprises cement mixed with shells containing a compressible element.

7. The perforating gun of claim 6, wherein the compressible element comprises one of a gas and vacuum.

8. The perforating gun of claim 6, wherein the shells comprise microspheres.

9. A perforating gun comprising:

a plurality of shaped charges; and

an encapsulant surrounding the plurality of shaped charges to provide structural support for the shaped charges,

wherein the encapsulant comprises a porous solid,

wherein the porous solid contains a phase change material.

10. A perforating gun comprising:

one or more shaped charges; and

an encapsulant surrounding the one or more shaped charges to provide structural support for the shaped charges,

wherein the encapsulant comprises a mixture of cement and hollow filler material.

11. The perforating gun of claim 10, wherein the hollow filler material comprises gas.

12. The perforating gun of claim 10, wherein the hollow filler material comprises a shell containing a gas or vacuum.

13. A perforating gun comprising:

a plurality of shaped charges; and

an encapsulant surrounding the plurality of shaped charges to provide structural support for the shaped charges, a support mechanism for the plurality of shaped charges, the support mechanism being surrounded at least in part by the encapsulant,

wherein the support mechanism comprises a strip.

14. The perforating gun of claim 13, wherein the support mechanism further comprises a twisted bracket having one or more support rings to receive the one or more shaped charges.

15. The perforating gun of claim 13, wherein the encapsulant comprises a polymer-based material.

16. The perforating gun of claim 15, wherein the encapsulant comprises a mixture of the polymer-based material and hollow filler material.

17. The perforating gun of claim 16, wherein the hollow filler material comprises gas.

18. The perforating gun of claim 16, wherein the hollow filler material comprises a shell containing a gas or vacuum.

19. A perforating gun comprising:

a plurality of shaped charges; and

an encapsulant surrounding the plurality of shaped charges to provide structural support for the shaped charges, a support mechanism for the plurality of shaped charges, the support mechanism being surrounded at least in part by the encapsulant,

wherein the support mechanism comprises a twisted bracket having one or more support rings to receive the one or more shaped charges.

20. A perforating gun comprising:

one or more shaped charges; and

an encapsulant surrounding the one or more shaped charges to provide structural support for the shaped charges; and

a support layer around at least a part of the encapsulant,

wherein the support layer is coated onto the outer surface of the encapsulant.

21. An apparatus for use in a wellbore, comprising:

explosives; and

an encapsulant surrounding at least portions of the explosives to provide structural support for the explosives,

the encapsulant comprising a material selected from the group consisting of a porous cement;

a mixture containing cement and hollow structures;

a mixture containing cement and microspheres;

a mixture containing epoxy and hollow structures; and

a mixture containing a hollow filler material, a heavy filler powder, and a binder/matrix.

22. The apparatus of claim 21, wherein the explosives are arranged in a phased pattern with respect to each other.

23. The apparatus of claim 21, wherein the explosives comprise shaped charges.

24. The apparatus of claim 21, further comprising a support layer around at least a part of the encapsulant.

25. The apparatus of claim 24, wherein the support layer is coated onto the encapsulant.

26. The apparatus of claim 24, wherein the support layer comprises a sleeve.

27. A method of providing structural support for explosives in a downhole tool, comprising:

arranging the explosives in a predetermined arrangement;

mounting the explosives on a support structure; and

encapsulating at least portions of the explosives and at least a portion of the support structure in a compound to support the explosives in the predetermined arrangement.

28. The method of claim 27, wherein arranging the explosives comprises arranging the explosives in a phased arrangement.

29. The method of claim 27, wherein arranging the explosives comprises arranging shaped charges of a perforating gun.

30. The method of claim 27, wherein encapsulating at least portions of the explosives comprises encapsulating with a porous material.

31. The method of claim 27, wherein encapsulating at least portions of the explosives comprises encapsulating with a porous solid.

32. The method of claim 27, wherein encapsulating at least portions of the explosives comprises encapsulating with porous cement.

33. The method of claim 27, wherein encapsulating in the compound comprises encapsulating in a compound selected from the group consisting of a porous cement;

a mixture containing cement and hollow structures;

a mixture containing cement and microspheres;

a mixture containing epoxy and hollow structures; and

a mixture containing a hollow filler material, a heavy filler powder, and a binder/matrix.