Active waveshaper for deep penetrating oil-field charges

Abstract

A shaped charge having a liner, a shaped charge case, high explosive between the ilner and the case, and an active wave shaping element that is made of an energetic material that reacts at a rate different from the high explosive. The wave shaping element is disposed in the high explosive between an apex of the liner and base of the shaped charge case. Example materials of the wave shaping element include HMX, RDX, PBX types, PETN, HNS, TATB, and combinations thereof.

1 . A shaped charge for use in perforating a wellbore comprising:
 a shaped charge case configured for use in a perforating gun;   a high explosive in the shaped charge case having a speed of detonation;   a liner adjacent the high explosive in the shaped charge case:   a wave shaping element comprising an energetic material having a speed of reaction less than the speed of detonation and disposed in a path, of a detonation wave that is between a location of initiation of the detonation wave and the liner, so that when the detonation wave is generated by detonation of the high explosive, the detonation wave Is shaped by the wave shaping element.   
     
     
         2 . The shaped charge of  claim 1 , wherein the detonation wave upstream of the wave shaping element, is more divergent than when the detonation wave is downstream, of the wave shaping element. 
     
     
         3 . The shaped charge of  claim 1 , wherein the wave shaping element comprises a material selected from the list consisting of HMX, RDX, PBX types, PETN, HNS, TATB, and combinations thereof. 
     
     
         4 . The shaped charge of  claim 1 , further comprising a cavity formed through an end of the shaped charge case, wherein the high explosive and liner is disposed in the cavity. 
     
     
         5 . The shaped charge of  claim 4 , further comprising a booster charge in an end of the shaped charge case opposite the end having the cavity, wherein the liner has a generally conical shape with a rounded apex facing the booster charge, and wherein the wave shaping element is disposed in a space between the apex and the booster charge. 
     
     
         6 . The shaped charge of  claim 1 , wherein the wave shaping element has a lenticular cross section and is generally coaxial with an axis of the shaped charge. 
     
     
         7 . The shaped charge of  claim 1 , wherein the high explosive comprises a material selected from the list consisting of HMX, RDX, PBX types, PETN, HNS, TATB, and combinations thereof. 
     
     
         8 . A method of perforating a wellbore comprising:
 a. providing a shaped charge having a shaped charge liner, high explosive adjacent the shaped charge liner, and a wave shaping element in the high explosive that comprises an energetic material that has a rate of reaction, that differs from a rate of reaction of the high explosive;   b. disposing the shaped charge in a wellbore; and   c. initiating detonation of tie high explosive to form a detonation wave for collapsing the shaped charge liner.   
     
     
         9 . The method of  claim 8 , wherein the detonation wave downstream of the wave shaping element diverges less than when upstream of the wave shaping element. 
     
     
         10 . The method of  claim 8 , wherein the step of initiating detonation of the high explosive comprises generating a detonation wave in a detonating cord, and transferring the detonation wave from the detonating cord to the high explosive. 
     
     
         11 . The method of  claim 8 , further comprising disposing the high explosive, shaped charge liner, and wave shaping element in a shaped charge ease to define a shaped charge. 
     
     
         12 . The method of  claim 8 , further comprising repeating step (a) multiple times to provide multiple shaped charges, disposing the multiple shaped charges into a perforating gun having a detonation cord. 
     
     
         13 . A perforating system comprising:
 a cylindrical perforating gun body;   shaped charges in the gun body comprising a shaped charge case having a cavity with, walls and a bottom, a shaped charge liner in the cavity, high explosive between the shaped charge liner and the walls and bottom of the cavity, and a wave shaping element in the cavity between an apex of the shaped charge liner and bottom of the cavity and that comprises a material that reacts at a rate different from that at which the high explosive reacts.   
     
     
         14 . The perforating system of  claim 13 , wherein the material of the wave shaping element comprises HMX, RDX, PBX types, PETN, HNS, TATB, and combinations thereof. 
     
     
         15 . The perforating system of  claim 13 , further comprising a detonating cord extending lengthwise through the gun body and disposed adjacent an end of the shaped charge case having a booster charge. 
     
     
         16 . The perforating system of  claim 13 , wherein the wave shaping element is coated with a fluorocarbon based polymer. 
     
     
         17 . The perforating system of  claim 13 , wherein the apex extends into the wave shaping element. 
     
     
         18 . The perforating system of  claim 13 , wherein the wave shaping element is spaced apart from the apex.