Drillable core perforating gun and method of utilizing the same

Abstract

The present invention includes a perforating gun and method of using the same to perforate casing in a wellbore. The perforating gun includes a hollow carrier having a core. Mounted within the core are components including at least one charge and at least one plug for sealing the charge within the core. Preferably, a pair of end plugs are used to seal the ends of the carrier about the charge or charges. A string of tubing is used to position the perforating gun adjacent the casing to be perforated. The charge or charges are detonated creating perforation tunnels in the casing and surrounding wellbore. A drill is then used to drill out the core of the carrier to provide ready access through the carrier for other tools and fluid flow. The carrier is ideally of a stronger material than the core components and enhances drillability of the core by providing guidance as the drill removes the core components.

What is claimed is:  
     
         1 . A perforating gun for perforating casing in a wellbore, the perforating gun comprising: 
 a carrier having a generally hollow interior forming a core;    at least one charge mounted within the hollow interior; and    a plug made of a soft, drillable material which seals at least a portion of the at least one charge within the carrier;    wherein the carrier remains intact after the at least charge has detonated and may serve as a guide to a drill to drill out the at least one plug and at least one charge from the core.    
     
     
         2 . The perforating gun of  claim 1  wherein: 
 a pair of plugs cooperate to seal the at least one charge in the carrier.  
 
     
     
         3 . The perforating gun of  claim 1  wherein: 
 there are a plurality of charges disposed in the carrier.  
 
     
     
         4 . The perforating gun of  claim 1  further comprising: 
 a charge strip for positioning the at least one charge within the carrier.  
 
     
     
         5 . The perforating gun of  claim 1  wherein: 
 the carrier is made of a material having a higher tensile strength than the at least one plug.  
 
     
     
         6 . A method of perforating a casing in a well core, the method comprising the steps of: 
 mounting a perforating gun on tubing and positioning the perforating gun in a well-bore adjacent to a casing to be perforated, the gun having a hollow carrier defining a core and having at least one charge stored in the core and having at least one plug which seals the charge within the carrier;    detonating the charge to perforate the adjacent casing; and    drilling out the core of the carrier to provide a drilled out passageway through which other tools and fluid may readily pass.    
     
     
         7 . The method of  claim 6  wherein: 
 the drilling out leaves the core of carrier relatively smooth such that other tools may pass there through without hanging up on the drilled out core.  
 
     
     
         8 . The method of  claim 6  wherein: 
 the plug is made of material which is softer than the carrier.  
 
     
     
         9 . The method of  claim 6  wherein: 
 the perforating gun includes a charge strip upon which the at least one charge is mounted; and  
 the step of drilling out the core removes the charge strip from the carrier.  
 
     
     
         10 . The method of  claim 6  wherein: 
 the perforating gun is mounted upon a string of hollow tubing and is placed adjacent the casing to be perforated; and  
 the core of the carrier, after the core is drilled out, is at least as large as the interior of the hollow tubing to thereby provide uninhibited passage of tools through the hollow tubing and the drilled out core of the carrier.  
 
     
     
         11 . The method of  claim 10  wherein: 
 the carrier is generally cylindrical and the outer diameter of the carrier is larger than the outer periphery of the tubing.  
 
     
     
         12 . The method of  claim 6  wherein: 
 at least a hundred feet of casing are perforated in a single detonation of the gun.  
 
     
     
         13 . The method of  claim 6  wherein: 
 at a thousand feet of casing are perforated in a single detonation of the gun.