Composite liners for perforators

Abstract

A shaped charge having a charge case and liner with an outer layer and an inner layer. The liner is a generally hollow frustoconically shaped member with an open end and a closed end, where the closed end of the liner inserts into an opening in the charge case. An explosive is provided between the liner and the charge case. The inner layer of the liner includes a higher density material than material used for forming the outer layer.

What is claimed is: 
     
         1 . A perforating gun comprising:
 a gun body;   a shaped charge in the gun body comprising,
 a charge case, 
 a liner in the charge case having an inner layer and an outer layer made of a material with a lower density and that is more ductile than a material in the inner layer. 
   
     
     
         2 . The perforating gun of  claim 1 , wherein the inner layer comprises tungsten and the outer layer comprises aluminum. 
     
     
         3 . The perforating gun of  claim 1 , wherein the liner is frustoconically shaped. 
     
     
         4 . The perforating gun of  claim 1 , wherein the inner and outer layers comprise cold pressed metal particles. 
     
     
         5 . The perforating gun of  claim 1 , further comprising a plurality of shaped charges and a detonation cord coupled with each of the shaped charges. 
     
     
         6 . The perforating gun of  claim 1 , further comprising explosive in the charge case and underneath the liner, wherein detonating the explosive inverts and discharges the liner from the charge case to form an elongate metal jet having a generally curved outer lateral periphery, wherein the jet perforates the gun body and deposits a slug on an inner surface of the gun body that blocks a flow of debris from inside of the gun body. 
     
     
         7 . The perforating gun of  claim 6 , wherein the slug is formed substantially from material making up the outer layer. 
     
     
         8 . A perforating system comprising:
 an annular perforating gun selectively inserted within a wellbore;   a shaped charge in the perforating gun comprising,
 a charge case having an opening and a substantially curved outer periphery adjacent the opening, 
 a frustoconically shaped liner inserted into the opening of the charge case that is made up of an inner layer having an outer surface covered by an outer layer that is more ductile than the inner layer. 
   
     
     
         9 . The perforating system of  claim 8 , further comprising an explosive in the charge case under the liner. 
     
     
         10 . The perforating system of  claim 8 , wherein the inner layer comprises tungsten cold pressed into shape. 
     
     
         11 . The perforating system of  claim 8 , wherein the outer layer comprises aluminum cold pressed into shape. 
     
     
         12 . A method of reducing debris created while perforating a wellbore comprising:
 providing a perforating gun with a shaped charge that comprises, a charge case, a liner in the charge case that has an inner layer and a ductile outer layer, and an explosive in the charge case under the liner;   disposing the shaped charge in the wellbore; and   detonating the explosive to create an explosion that inverts the liner and expels the liner from the charge case to form a metal jet that perforates a sidewall of the perforating gun and deposits a slug on an inner surface of the perforating gun that restricts debris from exiting the perforating gun.   
     
     
         13 . The method of  claim 12 , wherein the inner layer comprises tungsten particles and softer metal particles that are cold pressed into a frustoconical shape. 
     
     
         14 . The method of  claim 12 , wherein the outer layer comprises aluminum particles that are cold pressed into a frustoconical shape.