Method for the Enhancement of Injection Activities and Stimulation of Oil and Gas Production

Abstract

By removing material of low permeability from within and around a perforation tunnel and creating at least one fracture at the tip of a perforation tunnel, injection parameters and effects such as outflow rate and, in the case of multiple perforation tunnels benefiting from such cleanup, distribution of injected fluids along a wellbore are enhanced. Following detonation of a charge carrier, a second explosive event is triggered within a freshly made tunnel, thereby substantially eliminating a crushed zone and improving the geometry and quality (and length) of the tunnel. In addition, this action creates substantially debris-free tunnels and relieves the residual stress cage, resulting in perforation tunnels that are highly conducive to injection under fracturing conditions for disposal and stimulation purposes, and that promote even coverage of injected fluids across the perforated interval.

1 . A method for perforating a well for the enhancement of injection activities and stimulation of oil or gas production in an underground formation, said method comprising the steps of:
 a) loading one or more reactive shaped charges within a charge carrier;   b) positioning the charge carrier down a wellbore adjacent to the underground formation;   c) detonating the shaped charge to create a first and second explosive event, wherein the first explosive event creates one or more perforation tunnels within the adjacent formation, each of said one or more perforation tunnels surrounded by a crushed zone, and wherein the second explosive event induces at least one fracture at the tip of at least one perforation tunnel and further wherein the second explosive event expels debris from within the tunnel to the wellbore.   
   
   
       2 . The method of  claim 1  further comprising stimulating the formation by forcing fluid out of the perforation tunnels through said fracture within the formation. 
   
   
       3 . The method of  claim 1 , wherein the second explosive event further relieves a stress cage caused by plastic deformation surrounding the one or more perforation tunnels. 
   
   
       4 . The method of  claim 1 , wherein the second explosive event further results in the reduction of the amount of hydraulic horsepower required to effect a fracture stimulation. 
   
   
       5 . The method of  claim 1 , wherein the resulting tunnel depth following the second explosive event is substantially equal to the total depth of penetration 
   
   
       6 . The method of  claim 1 , wherein said second explosive event is triggered by said first explosive event. 
   
   
       7 . The method of  claim 1 , wherein said clear tunnel depth occurs independent of the prevailing rock lithology of said formation. 
   
   
       8 . The method of  claim 1 , wherein said clear tunnel depth occurs independent of permeability at the point of penetration. 
   
   
       9 . The method of  claim 1  further comprising an injection for stimulation of production of a gas from the formation. 
   
   
       10 . The method of  claim 8 , wherein said injection is comprised of a gas. 
   
   
       11 . The method of  claim 8 , wherein said injection is comprised of a fluid. 
   
   
       12 . The method of  claim 10 , wherein said fluid is comprised of one or more of the group consisting of brines, acids, bases, gels, emulsions, enzymes, chemical breakers, and polymers.