Direct Connectingh 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.

What is claimed is: 
     
         1 . A gun assembly for perforating wells comprising:
 at least one gun having a gun body casing, the casing being a hollow cylindrical tube, with an internally threaded fitting, a box fitting at one end, and an externally threaded fitting, a pin fitting at the distal end;
 wherein the pin fitting is a modified pin fitting, comprising:
 a length shorter than the length of 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 and slideably insertable therein;
 the charge carrier having a pin end nearest the pin end of the casing, and a distal box end nearest the box end of the casing; 
   a pin end cap secured to the pin end of the charge carrier, physically contacting 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 of the charge carrier 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 by   the pin end cap further comprising the 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, at the box end of the charge carrier, comprising:
 a circular disk perpendicular to the charge carrier's central axis, with an interior flat side toward the charge carrier, and a distal exterior flat side; 
 the interior side having a projecting cylinder coaxially oriented with diameter corresponding to the charge carrier diameter and secured to the box end of the charge carrier; 
 the circular disk having an exterior diameter substantially equal to the interior diameter of the casing's body tube; 
 
 the circular disk of the box end cap having an edge extending from one face of the circular disk and contacting the interior side wall of the casing's body tube 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 extending from the center of the box end cap's external flat side; 
 the electrical connection electrically isolated from the casing and from the charge carrier by the box end cap; and 
 a wire connected from the electrical connection, extending through the charge carrier, to the detonation circuit within the charge carrier. 
 
     
     
         4 . The gun assembly of  claim 3  wherein the electrical connection 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's internal diameter; 
 a second diameter larger than the charge carrier end's external diameter, and smaller than the internal diameter of the casing's body tube; 
 a third diameter larger than the internal diameter of the casing's body tube, and smaller than the diameter of the internal thread of the casing's box fitting,
 wherein the third diameter is captured between the end of the modified pin fitting of the casing, and the interior of the box fitting of a mated casing; 
 
 a fourth diameter smaller than the smallest diameter of the mated casing's box fitting's internal threads,
 the fourth diameter having at least two grooves for O-rings around the circumference, the O-rings mating against an interior surface 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 opening of the pin end cap with a retainer seal such that a contact pin of the pressure switch extends through the seal;
 the retainer seal having a hollow multi diameter cylindrical shape, the central opening having a retainer end extending and enlarging in external diameter to a sealing end:
 the central opening's diameter being greater than the contact pin of the pressure switch; 
 the retainer end external diameter being substantially equal to the diameter of the opening of the pin end cap, and securing the pressure switch therein; 
 the sealing end external diameter being larger than the diameter of the opening of the pen end cap; 
 the diameter change establishing a sealing face mating with the end of the pin end cap. 
 
 
     
     
         8 . The gun assembly of  claim 3  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 a contact pin of the pressure switch of the first gun to the electrical connection of the box end cap of the second gun. 
     
     
         10 . The gun assembly of  claim 7  wherein the retainer seal further comprises:
 a pressure guide directing blast pressure from a mated gun to the contact pin; 
 the pressure guide comprising a frustoconical central opening, enlarging toward the sealing end; 
 the length of the sealing end extending to the box end cap of a mated gun, and encompassing the electrical contacts of the mated gun.