Methods for treating a wellbore

Abstract

A method of converting a completed well into a dual completed well that includes selectively pumping a water-based fluid into a first production zone of the completed well, wherein the water-based fluid has a pH of greater than about 5; allowing the water-based fluid to form a continuous, non-flowing water-based gel in the first production zone of the completed well, wherein the water-based gel has a pH of greater than about 5; disposing a layer of cement into the completed well above the water- based gel; perforating a second production zone of the completed well in a location above the layer of cement; drilling through the layer of cement; and breaking the water-based gel located in the first production zone of the completed well, wherein the breaking comprises: exposing the water-based gel to a breaker fluid, wherein the breaker fluid has a pH of greater than about 5 is disclosed.

1 . A method of converting a completed well into a dual completed well, comprising:
 selectively pumping a water-based fluid into a first production zone of the completed well, wherein the water-based fluid has a pH of greater than about 5;   allowing the water-based fluid to form a continuous, non-flowing water-based gel in the first production zone of the completed well, wherein the water-based gel has a pH of greater than about 5;   disposing a layer of cement into the completed well above the water-based gel;   perforating a second production zone of the completed well in a location above the layer of cement;   drilling through the layer of cement; and   breaking the water-based gel located in the first production zone of the completed well, wherein the breaking comprises:
 exposing the water-based gel to a breaker fluid, wherein the breaker fluid has a pH of greater than about 5. 
   
     
     
         2 . The method of  claim 1 , further comprising:
 installing production tubing after breaking the water-based gel.   
     
     
         3 . The method of  claim 1 , further comprising:
 producing from both the first production zone and the second production zone of the completed well.   
     
     
         4 . The method of  claim 3 , further comprising:
 preventing commingling of production from the first and second production zones.   
     
     
         5 . The method of  claim 1 , wherein the first production zone is depleted. 
     
     
         6 . A method of treating a well, comprising:
 selectively pumping a water-based fluid into a production zone of the well, wherein the water-based fluid has a pH of greater than about 5;   allowing the water-based fluid to form a continuous, non-flowing water-based gel in the production zone of the well, wherein the water-based gel has a pH of greater than about 5; and   breaking the water-based gel, wherein the breaking comprises:   exposing the water-based gel to a breaker fluid, wherein the breaker fluid has a pH of greater than about 5.   
     
     
         7 . The method of  claim 6 , further comprising:
 drilling through the water-based gel prior to breaking the water-based gel.   
     
     
         8 . The method of  claim 6 , further comprising:
 completing the well after breaking the water-based gel.   
     
     
         9 . The method of  claim 6 , further comprising:
 producing from the well after breaking the water-based gel.   
     
     
         10 . The method of  claim 6 , further comprising:
 completing the well prior to selectively pumping the water-based fluid into the production zone of the well.   
     
     
         11 . The method of  claim 10 , wherein the water-based gel is used to preserve completion of the well.