Shaped charge liner and process

• US 20030131749A1
• Filed: 01/17/2002
• Published: 07/17/2003
• Est. Priority Date: 01/17/2002
• Status: Active Grant

• Current Assignee: Prime Perforating Systems Limited (Baker Hughes Company)
• Original Assignee: Prime Perforating Systems Limited (Baker Hughes Company)
• Inventors: Lussier, Michael Norman
• Granted Patent: US 6,668,726 B2
• Time in Patent Office: Days
• US Class Current: 102/306
• CPC Class Codes: F42B 1/028 characterised by the form of the liner
• CPC Class Codes: F42B 1/032 characterised by the material of the liner
• CPC Class Codes: F42B 1/036 Manufacturing processes therefor F42B33/0214 - F42B33/0292 take precedence

Abstract

Shaped charge liners, typically used in perforating guns, are formed from a zinc alloy of zinc and other metals such as aluminium and magnesium. The liners are formed into desired shapes, for example, by melting ingots and casting the alloy, or by machining bars formed from the alloy, or by stamping strips formed from the alloy, or by pressing powder formed from the alloy.

Claims

1. A shaped charge comprising:

a casing, a liner, and an explosive charge;

said casing having an apex at which to connect a detonation source, a mouth, and a divergent wall structure extending between said apex and said mouth, said divergent wall structure being narrower at said apex of said casing than at said mouth;

said liner having a central region and a divergent skirt extending from said central region, said central region lying closer to said apex than to said mouth, and said skirt being mounted to said divergent wall structure closer to said mouth than to said apex;

a charge cavity defined between said casing and said liner;

said explosive charge being contained within said charge cavity; and

said liner being formed from a metal material whose greatest component, by weight, is zinc.

2. The shaped charge of claim 1 wherein said metal material of said liner is predominantly zinc.

3. The shaped charge of claim 1 wherein said metal material of said liner is more than 70% zinc by weight.

4. The shaped charge of claim 1 wherein said metal material of said liner is more than 90% zinc by weight.

5. The shaped charge of claim 1 wherein said metal material of said liner is made of a metal material that is essentially zinc.

6. The shaped charge of claim 1 wherein said liner is made from zinc, aluminium and magnesium.

7. The shaped charge of claim 1 wherein said liner and said casing are made of the same material.

8. The shaped charge of claim 1 wherein said casing is formed from a metal material whose greatest component, by weight, is zinc.

9. The shaped charge of claim 1 wherein both said liner and said casing are made of a metal material that is at least 50% zinc by weight.

10. The shaped charge of claim 1 wherein said shaped charge has an axis of symmetry, and said casing has the form of a body of revolution relative to the axis of symmetry.

11. The shaped charge of claim 10 wherein said charge cavity has a first region lying on said axis of symmetry, and a second region lying radially away from said axis of symmetry, said second region having a diminished thickness relative to said first region.

12. The shaped charge of claim 11 wherein said liner has a conic region lying at a conic angle relative to said axis.

13. The shaped charge of claim 12 wherein said conic angle is in the range of 15 to 40 degrees.

14. The shaped charge of claim 1 wherein said liner is of constant thickness.

15. The shaped charge of claim 1 wherein said central region of said liner forms a bottom region of a valley and said divergent skirt forms sloped sides of said valley such that said liner is generally V-shaped.

16. The shaped charge of claim 1 wherein said liner is a casting.

17. A method of manufacturing a shaped charge, said method comprising the steps of:

providing a casing having an apex at which to connect a detonation source, a mouth, and a divergent wall structure extending between the apex and the mouth, the divergent wall structure being narrower at the apex of the casing than at the mouth;

forming a liner from a metal material whose greatest component, by weight, is zinc, the liner having a central region and a divergent skirt extending from the central region;

providing an explosive charge and locating said explosive charge in the casing;

locating the liner in position relative to the casing to form a charge cavity containing the explosive charge; and

said step of locating the liner in position including the step of locating said central region of the liner closer to said apex of said casing than to said mouth and locating the skirt adjacent to the divergent wall structure closer to the mouth than to the apex.

18. The method of claim 17 wherein said step of forming said liner includes the step of providing a material whose greatest component, by weight, is zinc.

19. The method of claim 17 wherein said step of forming said liner includes the step of providing a liner material that is predominantly zinc.

20. The method of claim 17 wherein said step of forming said liner includes the step of providing a liner material that is more than 70% zinc by weight.

21. The method of claim 17 wherein said step of forming said liner includes the step of providing a liner material that is more than 90% zinc by weight.

22. The method of claim 17 wherein said step of forming said liner includes the step of providing a liner material that is essentially zinc.

23. The method of claim 17 wherein said step of forming said liner includes the step of making said liner and said casing of the same material.

24. The method of claim 17 wherein said step of forming said liner includes the step of making both said liner and said casing of materials that are at least 50% zinc by weight.

25. The method of claim 17 wherein said step of forming said liner from a powder metal.

26. The method of claim 25 wherein said step of locating said liner includes the step of pressing said powder metal liner in a green state against said explosive charge.

27. The method of claim 25 wherein said step of forming said liner includes sintering said powder metal.

28. The method of claim 17 wherein said step of forming said liner includes the step of using a metal material of constant thickness.

29. The method of claim 17 wherein said step of forming said liner includes casting the liner.

30. The method of claim 17 wherein said step of forming said liner includes machining the liner.

31. A kit for assembling into a shaped charge for receiving and retaining an explosive charge for use with perforating guns, comprising:

a casing and a liner;

said casing having an apex at which to connect a detonation source, a mouth, and a divergent wall structure extending between said apex and said mouth, said divergent wall structure being narrower at said apex of said casing than at said mouth;

said liner having a central region and a divergent skirt extending from said central region, said skirt being mountable to said divergent wall structure to form a charge cavity between said liner and said casing for containing the explosive charge;

said liner being mountable to said casing, and said skirt being closer to said mouth than to said apex and said central region lying closer to said apex than to said mouth upon mounting said skirt to said divergent wall; and

said liner being formed from a metal material whose greatest component, by weight, is zinc.

32. The kit of claim 31 wherein said metal material of said liner is predominantly zinc.

33. The kit of claim 31 wherein said metal material of said liner is more than 70% zinc by weight.

34. The kit of claim 31 wherein said metal material of said liner is more than 90% zinc by weight.

35. The kit of claim 31 wherein said metal material of said liner is essentially zinc.

36. The kit of claim 31 wherein said casing is formed from a metal material whose greatest component, by weight, is zinc.

37. The kit of claim 31 wherein said liner and said casing are made of the same material.

38. The kit of claim 31 wherein said liner is a casting.

39. A method of manufacturing a shaped charge liner for use with a casing for containing an explosive charge, said casing having an apex at which to connect a detonation source, a mouth, and a divergent wall structure extending between said apex and said mouth, said divergent wall structure being narrower at said apex of said casing than at said mouth, comprising the steps of:

forming a liner, said liner having a central region and a divergent skirt extending from the central region;

said skirt being mountable to said divergent wall structure to form a charge cavity between said liner and said casing for containing the explosive charge;

said skirt being closer to said mouth than to said apex and said central region lying closer to said apex than to said mouth upon mounting said skirt to said divergent wall; and

said liner being formed from a metal material whose greatest component, by weight, is zinc.

40. The method of claim 39 wherein said step of forming said liner includes the step of providing a liner material that is predominantly zinc.

41. The method of claim 39 wherein said step of forming said liner includes the step of providing a liner material that is more than 70% zinc by weight.

42. The method of claim 39 wherein said step of forming said liner includes the step of providing a liner material that is more than 90% zinc by weight.

43. The method of claim 39 wherein said step of forming said liner includes the step of providing a liner material that is essentially zinc.

44. The method of claim 39 wherein said step of forming said liner includes the step of forming said liner from a powder metal.

45. The method of claim 44 wherein said step of forming said liner includes sintering said powder metal.

46. The method of claim 39 wherein said step of forming said liner includes the step of using a metal material of constant thickness.

47. The method of claim 39 wherein said step of forming said liner includes the step of casting the liner.

48. The method of claim 39 wherein said step of forming said liner includes the step of machining the liner.