Perforating a Well Formation

Abstract

A technique that is usable with a subterranean well includes reducing a stress on a formation in the well. The formation is perforated while the stress is reduced.

1 . A method usable with a subterranean well, comprising: 
 reducing a stress on a formation in the well; and    while the stress is reduced, perforating the formation.    
   
   
       2 . The method of  claim 1 , wherein the stress comprises an effective stress on the formation.  
   
   
       3 . The method of  claim 1 , wherein the stress is caused by a difference between a mean total stress of the formation and a pore fluid pressure of the formation.  
   
   
       4 . The method of  claim 1 , wherein the act of reducing comprises increasing a pore fluid pressure.  
   
   
       5 . The method of  claim 4 , wherein the act of reducing further comprises temporarily increasing the pore fluid pressure during a time interval, wherein the act of perforating occurs during the time interval.  
   
   
       6 . The method of  claim 5 , wherein the time interval is a function of a permeability of the formation.  
   
   
       7 . The method of  claim 1 , wherein the act of reducing comprises: 
 sealing off an interval of the well containing perforations; and    pressurizing the interval.    
   
   
       8 . The method of  claim 7 , further comprising: 
 perforating the formation to form the perforations.    
   
   
       9 . The method of  claim 1 , further comprising: 
 forming perforations in the formation prior to the act of perforating.    
   
   
       10 . The method of  claim 1 , wherein the act of reducing comprises: 
 pressuring the well with a heavy fluid to form a hydrostatic head to isolate a region of the well.    
   
   
       11 . The method of  claim 1 , wherein the perforating occurs in a first wellbore and the act of reducing is performed at least partially in another second wellbore.  
   
   
       12 . The method of  claim 11 , wherein the act of reducing further comprises pressurizing the second wellbore to reduce the stress of the formation near the first wellbore.  
   
   
       13 . The method of  claim 1 , wherein the act of reducing comprises applying thermal energy to the formation.  
   
   
       14 . The method of  claim 13 , wherein the act of applying thermal energy alters a pressure between the formation and the pore fluid.  
   
   
       15 . A system usable with a subterranean well, comprising: 
 a first tool to reduce a stress on a formation; and    a perforating tool to, while the stress is reduced, perforate the formation.    
   
   
       16 . The system of  claim 15 , wherein the stress comprises an effective stress on the formation.  
   
   
       17 . The system of  claim 15 , wherein the stress is caused by a difference between a mean total stress of the formation and a pore fluid pressure of the formation.  
   
   
       18 . The system of  claim 15 , wherein the first tool is used to increase a pore fluid pressure on the formation.  
   
   
       19 . The system of  claim 18 , wherein the first tool is used temporarily increase the pore fluid pressure during a time interval so that the perforating tool may form the perforations in the formation during the time interval.  
   
   
       20 . The system of  claim 19 , wherein the time interval is a function of a permeability of the formation.  
   
   
       21 . The system of  claim 15 , wherein the first tool and the perforating tool are part of a string, the string further comprising a sealing device to seal off an interval of the well containing the perforations so that the interval may be pressurized.  
   
   
       22 . The system of  claim 21 , wherein the perforating tool is adapted to form the perforations during the existence of the seal.  
   
   
       23 . The system of  claim 15 , wherein the first tool comprises a heater element.  
   
   
       24 . The system of  claim 15 , wherein the first tool and the perforating tool are part of a string.