Direct Connecting Gun Assemblies for Drilling Well Perforations

Abstract

A perforation gun assembly comprising a plurality of guns with a box fitting at one end and a modified pin fitting at the distal end; the modified pin fitting further comprising an end cap secured to an internal charger carrier, aligning a plurality of shape charges with scallops in the gun casing; and having a pressure switch, which connects to an electrical connection point at the box end of a charger carrier in an adjacent gun. The end cap being captured between the pin of one gun and the internal edge of the mating gun to protect and channel blast force to the pressure switch.

1 . A gun assembly for perforating wells comprising:
 at least one gun having a gun body casing, the casing being a hollow cylinder, with a box fitting at one end, and a modified pin fitting at the distal end;
 the modified pin fitting comprising a length of external thread shorter than the length of internal thread located in the box fitting; and 
 an alignment point for accepting an alignment pin; 
   a charge carrier, the charge carrier being a hollow cylinder, with exterior diameter less than the interior diameter of the casing;   a pin end cap secured to the pin end of the charge carrier and extending the charge carrier to a length approximately equal to the length of the casing, physically securing and electrically grounding the charge carrier to the casing;   the pin end cap further having an opening passing through the pin end cap for receiving a pressure switch secured therein;   a plurality of shape charges inside the charge carrier, the charges disposed radially toward the external circumference and inter connected by a detonator cord;   the detonator cord connecting with a detonation circuit within the charge carrier;   a plurality of scalloped recesses in the casing adjacent to, and aligned with each of the plurality of charges;   an alignment pin securing the charge carrier within the casing such that the charges are aligned with the scalloped recesses in the gun body.   
     
     
         2 . The gun assembly of  claim 1  wherein the gun further comprises:
 a box end cap, secured to the box fitting end of the charge carrier, having an exterior diameter substantially equal to the interior diameter of the casing; 
 the box end cap having an edge extending to one side of the external diameter of the box end cap, and biased outward from the central axis to substantially center the charge carrier within the casing. 
 
     
     
         3 . The gun assembly of  claim 2  wherein the box end cap further comprises:
 an electrical connection point extending from the center of the box end cap's external side; 
 the connection point being electrically isolated from the casing and from the charge carrier, and 
 a wire connected from the electrical connection point, extending through the charge carrier, to the detonation circuit within the charge carrier. 
 
     
     
         4 . The gun assembly of  claim 3  wherein the electrical connection point of the box end cap is electrically connected to a firing circuit for remotely detonating one or more guns individually. 
     
     
         5 . The gun assembly of  claim 1  wherein the pin end cap further comprises:
 a first diameter less than the charge carrier end; 
 a second diameter larger than the charge carrier end, and smaller than the internal diameter of the casing; 
 a third diameter larger than the internal diameter of the casing, and smaller than the diameter of the internal thread of the box fitting,
 wherein the third diameter is captured between the end of the modified pin fitting of the casing, and the interior shoulder of the box fitting of a mated casing; 
 
 a fourth diameter smaller than the smallest diameter of the mated casing's box fitting,
 the fourth diameter having at least two grooves for O-rings around the circumference, the O-rings mating against the interior cylinder of the smallest diameter of a mated casing's box fitting. 
 
 
     
     
         6 . The gun assembly of  claim 1  wherein the pin end cap further comprises an alignment point for accepting an alignment pin mating with the alignment point of the gun casing. 
     
     
         7 . The gun assembly of  claim 1  wherein the pressure switch is secured in the central opening of the pin end cap with a retainer seal such that the pressure switch's contact pin extends through the seal and is surrounded by a pressure guide directing blast pressure from a mated gun to the contact pin. 
     
     
         8 . The gun assembly of  claim 1  wherein the gun assembly is comprised of
 connecting a first gun, of the at least one gun, to a second gun; 
 by mating the modified pin fitting of the first gun to the box fitting of the second gun. 
 
     
     
         9 . The gun assembly of  claim 8  wherein the mating of the guns electrically connects the pressure switch's contact pin of the first gun roan electrical connection point of the box end cap of the second gun.