Angled perforating device for well completions

Abstract

The present invention is an improvement in the design of a perforating gun to perforate the casing and rock formations in oil and gas wells. Perforating guns are cylindrical vessels with explosive charges at specified intervals designed to shoot perpendicularly outwardly through the vessel, perforating the casing and into the rock formation. As most wells are generally straight and most formations are relatively flat, the perforations are horizontal in the same direction as the bedding plane of the rock formations. The present invention is to angle the explosive charges so as to cause the perforation to shoot at an angle to horizontal and across the bedding planes of the rock formations. The angled perforations can result in improved completions in stratified reservoirs and fractured reservoirs by contacting all the stratified layers for production and contacting more of the fractures for production. Similarly, the angled perforations would contact more of the cleats in coal seams for improved production of coal be methane. Numerous other examples of reservoir conditions could make the present invention advantageous in contacting more of the formation with less perforating charges while at the same time improving production rates and long term recovery of hydrocarbons.

1 . A well perforating device, within a wellbore, comprising a plurality of perforating charges positioned by said well perforating device, each of said perforating charges containing a hollow cone shaped explosive charge so that upon detonation of the hollow cone shaped charge a perforating jet is formed that creates a perforation away from said perforating device into a rock formation, an improvement comprising; 
 a. positioning said perforating charges at an angle away from perpendicular to said well perforating device so as to contact more of said rock formation adjacent to said wellbore with fewer of said plurality of perforating charges.    
   
   
       2 . The perforating device of  claim 1  wherein the need for fewer of said plurality of perforating charges is a means to reduce stress to said wellbore and said rock formation.  
   
   
       3 . The perforating device of  claim 1  wherein said rock formation has bedding planes.  
   
   
       4 . A well perforating device comprising a plurality of perforating charges positioned by said well perforating device, each of said perforating charges containing a hollow cone shaped explosive charge so that upon detonation of the hollow cone shaped charge a perforating jet is formed that creates a perforation away from said perforating device into a rock formation, an improvement comprising; 
 a. positioning said perforating charges at an angle away from perpendicular to said well perforating device so as to penetrate a plurality of intervals of higher permeability in said rock formation.    
   
   
       5 . The perforating device of  claim 4  wherein said plurality of intervals of higher permeability are horizontal bedding planes of said rock formation.  
   
   
       6 . The perforating device of  claim 4  wherein said plurality of intervals of higher permeability are fractures in said rock formation.  
   
   
       7 . The perforating device of  claim 4  wherein said plurality of intervals of higher permeability are cleats in a coal formation.  
   
   
       8 . The perforating device of  claim 4  wherein the penetration of said plurality of intervals of higher permeability is a means for contacting more of said rock formation allowing greater flow of fluids from said rock formation.  
   
   
       9 . The perforating device of  claim 4  wherein the penetration of said plurality of intervals of higher permeability is a means for decreasing the need for stimulation treatments.  
   
   
       10 . The perforating device of  claim 4  wherein the penetration of said plurality of intervals of higher permeability is a means for contacting more of said rock formation allowing for improved stimulation treatments.  
   
   
       11 . The perforating device of  claim 4  wherein angling said perforating charges away from a horizontal fluid contact in said rock formation and penetration of said plurality of intervals of higher permeability is a means for increasing the flow of fluids from said rock formation while decreasing the change in said horizontal fluid contact in said rock formation.  
   
   
       12 . A perforating charge where an angle away from perpendicular from the perforating device is incorporated into an angle between a prima cord holder and the axis of said perforating charge.  
   
   
       13 . A charge tube holder with a plurality of supports on which said perforating charges rest as a means to position said perforating charges at said angle away from perpendicular to said perforating device.  
   
   
       14 . The charge tube holder of  claim 13  wherein a prima cord wraps around the outside of said charge tube holder.  
   
   
       15 . The charge tube holder of  claim 13  wherein said perforating charges and said prima cord are within said charge tube holder.  
   
   
       16 . The charge tube holder of  claim 13  wherein a plurality of bent portions of said charge tube holder to further position said perforating charges at said angle away from perpendicular to said perforating device.  
   
   
       17 . A well perforating device with at least one perforating charge positioned at an angle away from perpendicular to said well perforating device as a means to penetrate intervals of higher permeability in a rock formation.  
   
   
       18 . The well perforating device of  claim 17  wherein said intervals of higher permeability are horizontal bedding planes of said rock formation.  
   
   
       19 . The well perforating device of  claim 17  wherein said intervals of higher permeability are fractures of said rock formation.  
   
   
       20 . The well perforating device of  claim 17  wherein penetration of said intervals of higher permeability is a means to contact more of said rock formation allowing greater flow of fluids from said rock formation.  
   
   
       21 . The well perforating device of  claim 17  wherein penetration of said intervals of higher permeability is a means to decrease the need for stimulation treatments.  
   
   
       22 . The well perforating device of  claim 17  wherein penetration of said intervals of higher permeability is a means to contact more of said rock formation allowing for better stimulation treatments.  
   
   
       23 . The well perforating device of  claim 17  wherein angling said perforating charge away from a horizontal fluid contact in said rock formation and penetrating said intervals of higher permeability as a means to increase the flow of fluids from said rock formation while decreasing the change in said horizontal fluid contact.