Oil well perforators
View Patent ↗An oil and gas well shaped charge perforator capable of providing an exothermic reaction after detonation is provided, comprising a housing, a high explosive, and a reactive liner where the high explosive is positioned between the reactive liner and the housing. The reactive liner is produced from a composition which is capable of sustaining an exothermic reaction during the formation of the cutting jet. The composition may be selected from any known formulation which is suitable for use in an oil and gas well perforator, typically the composition will comprise at least one metal and at least one non-metal, wherein the non-metal is selected from a metal oxide, or any non-metal from Group III or Group IV or at least two metals such as to form an intermetallic reaction. Typically at least one of the metals in the invention may be selected from Al, Ce, Li, Mg, Mo, Ni, Nb, Pb, Pd, Ta, Ti, Zn or Zr. The liner composition may preferably be a pressed particulate composition, such that the material is consolidated under pressure to form the desired shape of the liner. To aid consolidation a binder may also be added.
1. A reactive, oil and gas well shaped charge perforator comprising a liner and an associated shaped charge, whereby the liner is a green compacted particulate composition formed from a powder mixture comprising at least two metal elements, and whereby the liner is reactive such that the at least two metal elements will undergo an intermetallic alloying reaction to give an exothermic reaction upon activation of the associated shaped charge, and in which the at least two metal elements are provided in respective proportions calculated to give an electron concentration of 1.5, and wherein the composition further comprises at least one further inert metal, wherein the at least one further inert metal is not capable of an exothermic reaction with the at least two metal elements upon activation of the shaped charge liner.
2. A liner according to claim 1 in which one of the metals is aluminium.
3. A liner according to claim 1 in which one of the metals is selected from nickel and palladium.
4. A liner according to claim 1 , wherein a binder is added to aid consolidation.
5. A liner according to claim 1 , wherein at least one of the metals is coated with a binder.
6. A liner according to claim 4 , wherein the binder is selected from a polymer.
7. A liner according claim 6 wherein the binder is selected from a stearate, wax or epoxy resin.
8. A liner according to claim 6 , wherein the polymer is an energetic polymer.
9. A liner according to claim 8 , wherein the energetic binder is selected from Polyglyn (Glycidyl nitrate polymer), GAP (Glycidyl azide polymer) or Polynimmo (3-nitratomethyl-3-methyloxetane polymer).
10. A liner according to claim 4 , wherein the binder is selected from lithium stearate or zinc stearate.
11. A liner according to claim 4 , wherein the binder is present in the range of from 0.1 to 5% by mass.
12. A liner according to claim 1 , wherein the composition of at least two metals is particulate, the particles having a diameter 10 μm or less.
13. A liner according to claim 12 , wherein the particles are 1 μm or less in diameter.
14. A liner according to claim 13 , wherein the particles are 0.1 μm or less in diameter.
15. A liner according to claim 1 , wherein the thickness of liner is selected in the range of from 1 to 10% of the liner diameter.
16. A liner according to claim 15 wherein the thickness of liner is selected in the range of from 1 to 5% of the liner diameter.
17. A liner according to claim 1 , wherein the thickness of the liner is non-uniform across the surface area of the liner.
18. A liner according to claim 1 , wherein the at least one further metal is selected from copper, tungsten, or an alloy thereof.
19. A perforator comprising a housing, a quantity of high explosive located within the housing and a liner according to claim 1 located within the housing so that the high explosive is positioned between the liner and the housing.
20. A perforation gun comprising one or more shaped charge perforators according to claim 1 .
21. A method of completing an oil or gas well using one or more shaped charge liners according to claim 1 .
22. A method of completing an oil or gas well using a one or more shaped charge perforators, according to claim 1 .
23. A method of completing an oil or gas well using one or more perforation guns according to claim 20 .
24. A method of improving fluid outflow from a well comprising the step of perforating the well using one or more perforators according to claim 1 .
25. A liner according to claim 1 wherein the composition of at least two metals is a stoichiometric composition of two metals.
26. A liner according to claim 1 in which one of the metals is selected from iron, molybdenum, nickel and palladium.
27. A liner according to claim 5 wherein the binder is selected from a polymer.
28. A reactive oil and gas well shaped charge perforator comprising a liner and an associated shaped charge, whereby the liner is a green compacted particulate composition formed from a powder mixture comprising two metal elements, nickel and aluminium, and whereby the liner is reactive such that the two metal elements will undergo an intermetallic alloying reaction to give an exothermic reaction upon activation of the associated shaped charge, and in which the two metal elements are provided in respective proportions calculated to give an electron concentration of 1.5, thereby forming the intermetallic compound NiAl, and wherein the composition further comprises at least one further inert metal, wherein the at least one further inert metal is not capable of an exothermic reaction with the two metal elements upon activation of the shaped charge liner.