Slot Perforating Assembly

Abstract

Disclosed herein is a perforating system including a perforating gun and, more particularly, disclosed are methods and apparatuses using a conical perforating assembly. In one aspect, embodiments relate to a perforating assembly, that includes a charge carrier, a liner disposed in the charge carrier, and an explosive charge disposed between the charge carrier and the liner and supported on the charge carrier, where the liner is supported on the explosive charge, where the perforating assembly has an asymmetric profile.

What is claimed is: 
     
         1 . A perforating assembly, comprising:
 a charge carrier;   a liner disposed in the charge carrier, wherein the perforating assembly has an asymmetric profile, wherein the asymmetric profile comprises a structural asymmetry in the liner, wherein the structural asymmetry in the liner includes a variable thickness having a first thickness at a first radial coordinate and a second thickness at a second radial coordinate, wherein the first radial coordinate and the second radial coordinate are spaced apart by at least 30 degrees about a central axis of the liner, wherein the first thickness of the liner at the first radial coordinate is different by at least 5% from the second thickness of the liner at the second radial coordinate, and wherein a transition between the first thickness of the liner and the second thickness of the liner comprises gradual tapering; and   an explosive charge disposed between the charge carrier and the liner and supported on the charge carrier, wherein the liner is supported on the explosive charge.   
     
     
         2 . The perforating assembly of  claim 1 , wherein the perforating assembly is a conical perforating assembly or a hemispheric perforating assembly. 
     
     
         3 . The perforating assembly of  claim 1 , wherein the asymmetric profile further comprises a structural and/or material asymmetry in the charge carrier. 
     
     
         4 . The perforating assembly of  claim 3 , wherein the structural and/or material asymmetry comprises a difference in thickness of the charge carrier by at least 5% for two radial coordinates spaced apart by at least 30 degrees about the central axis of the liner. 
     
     
         5 . The perforating assembly of  claim 4 , wherein a transition between a first thickness of the charge carrier and a second thickness of the charge carrier comprises gradual tapering. 
     
     
         6 . (canceled) 
     
     
         7 . The perforating assembly of  claim 1 , wherein the asymmetric profile comprises at least one material asymmetry in the liner selected from the group consisting of different density, different tensile strength, different hardness, different ductileness, different toughness, different elasticity, different stress-strain response, and any combination thereof. 
     
     
         8 . The perforating assembly of  claim 1 , wherein the liner comprises:
 a first section comprising a first material; and   a second section comprising a second material,   wherein the first material has a different density than the second material.   
     
     
         9 . The perforating assembly of  claim 1 , wherein the explosive charge comprises:
 a first section comprising a first explosive; and   a second section comprising:
 a second explosive different from the first explosive, and/or 
 a higher concentration of the first explosive. 
   
     
     
         10 . A perforating system, comprising:
 a perforating gun, comprising:
 a gun body; 
 a charge tube disposed in the gun body; and 
 a plurality of perforating assemblies arranged in the charge tube, wherein at least one perforating assembly of the plurality of perforating assemblies has an asymmetric profile, wherein each perforating assembly of the plurality of perforating assemblies comprises a charge carrier, an explosive charge supported on the charge carrier, and a liner supported on the explosive charge, wherein the asymmetric profile comprises a structural asymmetry in the charge carrier, wherein the structural asymmetry in the charge carrier includes a variable thickness having a first thickness at a first radial coordinate and a second thickness at a second radial coordinate, wherein the first radial coordinate and the second radial coordinate are spaced apart by at least 30 degrees about a central axis of the charge carrier, wherein the first thickness of the charge carrier at the first radial coordinate is different by at least 5% from the second thickness of the charge carrier at the second radial coordinate, and wherein a transition between the first thickness of the charge carrier and the second thickness of the charge carrier comprises gradual tapering. 
   
     
     
         11 . The perforating system of  claim 10 , wherein the perforating system further comprising an additional perforating gun that comprises an additional gun body, an additional charge tube and a plurality of additional perforating assemblies, each additional perforating assembly also individually comprising a charge carrier, a conical liner, and an explosive charge. 
     
     
         12 . The perforating system of  claim 10 , wherein the asymmetric profile further comprises a structural and/or material asymmetry in the liner. 
     
     
         13 . The perforating system of  claim 10 , wherein the perforating gun comprises at least one conical or hemispheric perforating assembly. 
     
     
         14 . The perforating system of  claim 10 , wherein for a given cross-section of the at least one perforating assembly, a first thickness of the liner of the at least one perforating assembly at a first radial coordinate is different by at least 5% from at least a respective second thickness of the liner of the at least one perforating assembly at a second radial coordinate. 
     
     
         15 . A method, comprising:
 introducing at least a perforating gun into a wellbore extending into a subterranean formation, wherein the perforating gun comprises one or more perforating assemblies having an asymmetric profile and comprising a charge carrier, an explosive charge supported on the charge carrier, and a liner supported on the explosive charge, wherein the perforating assembly has an asymmetric profile, wherein the asymmetric profile comprises a structural asymmetry in the liner, wherein the structural asymmetry in the liner includes a variable thickness having a first thickness at a first radial coordinate and a second thickness at a second radial coordinate, wherein the first radial coordinate and the second radial coordinate are spaced apart by at least 30 degrees about a central axis of the liner, wherein the first thickness of the liner at the first radial coordinate is different by at least 5% from the second thickness of the liner at the second radial coordinate, and wherein a transition between the first thickness of the liner and the second thickness of the liner comprises gradual tapering;   lowering the perforating gun to a target depth in the wellbore; and   firing the at least one perforating assembly to perforate casing disposed in the wellbore, thereby forming one or more slot perforations.   
     
     
         16 . The method of  claim 15 , wherein the asymmetric profile causes an actual trajectory of a projectile to vary from its initial firing direction, whereby a profile of the perforation is elongated with respect to that which would be expected for the same perforating gun without the asymmetric profile. 
     
     
         17 . The method of  claim 16 , wherein a central axis of the at least one perforating assembly is aimed directly perpendicular to the casing during firing, wherein the projectile enters the wellbore casing at an angle relative to the central axis. 
     
     
         18 . The method of  claim 15 , wherein the at least one perforating assembly has a substantially conical or hemispheric profile. 
     
     
         19 . (canceled) 
     
     
         20 . The method of  claim 15 , wherein the structural asymmetry in the liner is configured to elongate the one or more slot perforations by about 10% to about 500%.