Hydraulically-Actuated Explosive Downhole Tool

Abstract

A downhole tool comprising a first section having an internal sidewall defining at least a portion of a flowpath, and a ported outer sidewall and an explosive having at least a portion within said first section. An annular portion has at least one chamber having an end positioned adjacent to the explosive and an inlet providing a communication path to said flowpath. A detonator assembly is located within each chamber proximal to the explosive such that detonation of the assembly causes detonation of the explosive. A firing pin is propelled toward the detonation assembly by providing communication between the chamber and the flow path, causing a pressure differential between the pressure isolated ends of the firing pin.

We claim: 
     
         1 . A downhole tool for stimulating a hydrocarbon-producing formation, the downhole tool comprising:
 a first section having an internal sidewall defining at least a portion of a flowpath, and an outer sidewall;   at least one explosive having at least partly within said first section;   an annular portion with at least one chamber having an end positioned adjacent to said at least one explosive and an inlet;   at least one detonator assembly within said at least one chamber proximal to said end;   at least one firing pin within said at least one chamber, said at least one firing pin having a first end pressure isolated from a second end;   at least one sleeve defining at least a portion of said flowpath and moveable between a first position and a second position, wherein in said first position said sleeve assembly is between the inlet of said at least one chamber and said flowpath.   
     
     
         2 . The downhole tool of  claim 1  wherein at least a portion of said at least one explosive is between said internal sidewall and said outer sidewall. 
     
     
         3 . The downhole tool of  claim 2  wherein said at least one detonator assembly comprises a isolation bulkhead proximal to said at least one explosive, a shaped charge adjacent said isolation bulkhead, a primer case adjacent said shaped charge, and a primer adjacent said primer case. 
     
     
         4 . The downhole tool of  claim 1  further comprising a retaining pin connected to said firing pin and occupying a portion of said inlet. 
     
     
         5 . The downhole tool of  claim 1  wherein said sleeve assembly comprises:
 a first sleeve having a first end surface, a second end surface, a cylindrical outer surface extending between said first end surface and said second end surface and defining a first groove circumscribing said first sleeve; 
 a second sleeve having a first end surface, a second end surface, a cylindrical outer surface extending between said first end surface and said second end surface and defining a second groove circumscribing said second sleeve; and 
 a collet ring occupying said first groove and said second groove. 
 
     
     
         6 . The downhole tool of  claim 5  wherein in said first position said second sleeve is attached to said second section with a plurality of shear pins. 
     
     
         7 . The downhole tool of  claim 1  further comprising a detonator cord connected to the detonator assembly and the at least one explosive. 
     
     
         8 . A downhole tool for stimulating a hydrocarbon-producing formation, the downhole tool comprising:
 a mandrel defining at least a portion of a flowpath;   at least one explosive adjacent said mandrel;   a sleeve adjacent said at least one explosive;   at least one detonator assembly adjacent to said at least one explosive;   at least one firing pin operable to contact said at least one detonator assembly, said firing pin having a first end pressure isolated from a second end;   a housing; and   a sleeve assembly moveable between a first position and a second position and defining a portion of said flowpath.   
     
     
         9 . The downhole tool of  claim 8  wherein:
 said at least one explosive is circumferentially disposed around at least a portion of said mandrel; and 
 said sleeve is circumferentially disposed around at least a portion of said at least one explosive. 
 
     
     
         10 . The downhole tool of  claim 8  further comprising:
 an annular portion; 
 at least one chamber disposed within said annular portion, said at least one chamber having an end longitudinally adjacent to said at least one explosive and an inlet; and 
 wherein said at least one detonator assembly is located at said end of said at least one chamber.