Perforating tandem sub with thermoplastic core and body and encapsulated pin

Abstract

A hybrid sub for perforating guns includes a metallic tubular body. A metallic pin member is encapsulated by a plastic body. The plastic body preferably has threads on exterior surface thereof which form a thread union with threads on the interior surface of the metallic tubular body. The pin member may be threadedly received in the interior plastic body. A perforating gun sub having a pin member encapsulated by a plastic body is also disclosed, wherein the need for an outer metallic tubular body is eliminated.

We claim: 
     
         1 . A sub for perforating guns comprising:
 a metallic tubular body having an interior with female threads on a surface thereof;   a plastic body having male threads on an exterior surface thereof; said plastic body being threadedly received in the interior of said metallic tubular body; and   a metallic pin member extending through the interior of said metallic tubular body, said pin member being encapsulated by said plastic body.   
     
     
         2 . The sub for perforating guns of  claim 1 , wherein said plastic body is not composed of a Polyether Ether Ketone (PEEK) material. 
     
     
         3 . The sub for perforating guns of  claim 1 , said pin member having a central section and outwardly-extending end sections, said central section having a maximum diameter greater than diameters of said outwardly-extending end sections. 
     
     
         4 . The sub for perforating guns of  claim 3 , said central section of said metallic pin member comprises a plurality of grooves . 
     
     
         5 . The sub for perforating guns of  claim 1 , further comprising a plurality of o-rings positioned between said plastic body and said metallic tubular body. 
     
     
         6 . The sub for perforating guns of  claim 1 , said metallic pin member being a conductive material. 
     
     
         7 . The sub for perforating guns of  claim 1 , said metallic tubular body having a ledge at one end thereof, said plastic body having a flange configured to abut said ledge of said metallic tubular body. 
     
     
         8 . The sub for perforating guns of  claim 1 , said metallic pin member being partially encapsulated, wherein end sections of said metallic pin member are exposed so as to connect to adjacent perforating gun sections. 
     
     
         9 . The sub for perforating guns of  claim 1 , said pin member having male threads on an exterior surface thereof, said plastic body having female threads on an interior surface thereof, said metallic pin member being threadedly received in an interior of said plastic body. 
     
     
         10 . The sub for perforating guns of  claim 9 , wherein said pin member has at least one groove on the exterior surface thereof, and wherein at least one o-ring is received by said at least one groove of said pin member. 
     
     
         11 . The sub for perforating guns of  claim 1 , said plastic body being composed of a nylon thermoplastic material with glass fill. 
     
     
         12 . A sub for perforating guns comprising:
 a plastic body having male threads on an exterior surface thereof; and   a metallic pin member extending through an interior of said plastic body, said pin member being encapsulated by said plastic body.,   
     
     
         13 . The sub for perforating guns of  claim 12 , said pin member having a central section and outwardly extending end sections, said central section having a maximum diameter greater than diameters of said outwardly extending end sections 
     
     
         14 . The sub for perforating guns of  claim 13 , said central section of said pin member comprising a plurality of grooves. 
     
     
         15 . The sub for perforating guns of  claim 12 , wherein said plastic body is not composed of a Polyether Ether Ketone (PEEK) material. 
     
     
         16 . The sub for perforating guns of  claim 12 , said pin member being a conductive material. 
     
     
         17 . A sub for perforating guns comprising:
 a metallic tubular body having an interior with female threads on a surface thereof;   a plastic body having male threads on an exterior surface thereof; said plastic body being threadedly received in the interior of said metallic tubular body; and   a metallic pin member extending through the interior of said metallic tubular body, said pin member being encapsulated by said plastic body, said pin member having male threads on an exterior surface thereof, said plastic body having female threads on an interior surface thereof, said pin member being threadedly received in an interior of said plastic body.   
     
     
         18 . The sub for perforating guns of  claim 17 , said pin member having at least one groove on said exterior surface thereof, wherein at least one o-ring is positioned in said at least one groove. 
     
     
         19 . The sub for perforating guns of  claim 17 , said plastic body having a ledge at one end thereof, said pin member having a flange configured to abut said ledge of said plastic body. 
     
     
         20 . The sub for perforating guns of  claim 17 , wherein said plastic body is not composed of a Polyether Ether Ketone (PEEK) material.