Charge tube end plate

Abstract

An end plate for securing and orienting a charge tube within a downhole-perforating gun. The end plate includes apertures for receiving locating tabs on the end of the charge tube to ensure the end plate is affixed to the charge tube in a specific orientation. The end plate includes an alignment tab that mates with a corresponding alignment groove in the perforating gun barrel for ensuring insertion of the charge tube into the perforating gun barrel in correct orientation to ensure the perforating charges exit through pre-designed scallops in the perforating gun barrel. A series of apertures may be present within the end plate to allow usage with one of a variety of sizes of charge tube. The end plate may include manipulation spaces along the circumference of the end plate to allow the end plate to be properly positioned or retrieved. The end plate may include an attachment system for attachment of an initiating device.

1 . An end plate for use in the assembly of a perforating gun, the end plate comprising: 
 (a) a plate member having an outer perimeter adapted to be slideable within a perforating gun barrel; and    (b) an alignment system without the outer perimeter adapted for mating in specific orientation with the inner surface of the perforating gun barrel,    the plate member having one or more alignment apertures for aligning and mating with one or more corresponding locating tabs of a charge tube.    
   
   
       2 . The end plate of  claim 1 , wherein the one or more alignment apertures are arranged asymmetrically.  
   
   
       3 . The end plate of  claim 1  wherein a portion of the outer perimeter is recessed, providing a gap to permit the passage of gas past the end plate when the perforating gun is assembled, to facilitate retrieval of the end plate and charge tube from the perforating gun barrel, or to ease manipulation during assembly or disassembly.  
   
   
       4 . The end plate of  claim 1 , wherein the one or more alignment apertures comprise a series of apertures for mating with the locating tabs of one of a variety of sized charge tubes.  
   
   
       5 . The end plate of  claim 1 , wherein the plate member comprises a plate passage to permit passage of an initiating device.  
   
   
       6 . The end plate of  claim 5 , wherein the passage comprises a central bore.  
   
   
       7 . The end plate of  claim 5 , wherein the initiating device comprises a detonating cord.  
   
   
       8 . The end plate of  claim 1 , wherein the alignment system comprises an alignment tab extending from the outer perimeter of the plate member and a corresponding alignment groove within the inner circumference of the perforating gun barrel.  
   
   
       9 . The end plate of  claim 1 , further comprising an attachment system for attachment of an initiating device.  
   
   
       10 . The end plate of  claim 9 , wherein the attachment system comprises a puck adapted to attach to the end plate, the puck having a threaded aperture having a compression chamber, the aperture adapted to receive a compressible member and a threaded tube, wherein tightening the threaded tube into the threaded aperture compresses the compressible member in the compression chamber to frictionally engage the initiating device.  
   
   
       11 . The end plate of  claim 10 , wherein the initiating device comprises a detonating cord.  
   
   
       12 . The end plate of  claim 10 , wherein the compressible member is a cylindrical member having a central passage for passage of the initiating device, or is an o-ring.  
   
   
       13 . A process for assembling a perforating gun comprising the steps of obtaining a charge tube with open ends, the charge tube loaded with charges and having an arrangement of locating tabs on at least one of the open ends; providing an end plate slideable within a perforating gun barrel and having a corresponding arrangement of alignment apertures for mating with the locating tabs, the end plate also having an alignment system for mating in specific orientation with the inner surface of a perforating gun barrel; affixing the end plate against the end of the charge tube such that the locating tabs mate with the alignment apertures; and inserting the charge tube and end plate into the perforating gun barrel such that the alignment system properly orients the end plate and the charge tube within the perforating gun barrel to align the charges with weakened or scalloped portions of the perforating gun barrel.  
   
   
       14 . The process of  claim 13 , wherein the arrangement of locating tabs is asymmetrical.  
   
   
       15 . A universal end plate for use in the assembly of a perforating gun, the end plate comprising: 
 (a) a plate member having an outer perimeter slideable within a perforating gun barrel; and    (b) an alignment system without the outer circumference for mating in specific orientation with the inner surface of the perforating gun barrel,    the plate member having at least two sets of alignment apertures, each set of apertures including one or more apertures for mating with corresponding locating tabs of one of a variety of sized charge tubes.    
   
   
       16 . The end plate of  claim 15 , wherein the one or more apertures is/are arranged asymmetrically.  
   
   
       17 . The end plate of  claim 15 , wherein at least a portion of the outer perimeter is recessed, providing a gap to permit the passage of gas past the end plate when the perforating gun is assembled, or to facilitate retrieval of the end plate and charge tube from the perforating gun barrel.  
   
   
       18 . The end plate of  claim 15 , wherein the plate member includes a passage to permit passage of an initiating device.  
   
   
       19 . The end plate of  claim 18 , wherein the passage comprises a central bore.  
   
   
       20 . The end plate of  claim 15 , wherein the alignment system includes an alignment tab extending from the outer perimeter of the plate member and a corresponding alignment groove within the inner circumference of the perforating gun barrel.  
   
   
       21 . The end plate of  claim 15 , further comprising an attachment system for attachment of an initiating device.  
   
   
       22 . The end plate of  claim 21 , wherein the attachment system comprises a puck adapted to attach to the end plate, the puck having a threaded aperture having a compression chamber, the aperture adapted to receive a compressible member and a threaded tube, wherein tightening the threaded tube into the threaded aperture compresses the compressible member in the compression chamber to frictionally engage the initiating device.  
   
   
       23 . The end plate of  claim 22 , wherein the compressible member is a cylindrical member having a central passage for passage of the initiating device or is an o-ring.