Zonal Isolation Systems For Subterranean Wells

Abstract

A zonal isolation system for a subterranean well comprises at least one tubular body that comprises at least one semi-permeable membrane, or at least one removable material or both. The semi-permeable membrane is permeable to one or more activators that may cause a cement slurry to begin setting. The tubular body may comprise openings that are covered by or filled with a removable material. After a primary cementing treatment has been completed, the activator may be introduced into the tubular body, whereupon it passes through the tubular body and out into the cement slurry.

1 . A zonal isolation system for a subterranean well, comprising at least one tubular body that comprises:
 (i) at least one semi-permeable membrane; or   (ii) at least one semi-permeable membrane covered by a removable material; or   (iii) at least one opening covered by or filled with a removable material, or both; or   (iv) a combination thereof.   
     
     
         2 . The system of  claim 1 , wherein the semi-permeable membrane is permeable to one or more activators in the list comprising sodium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium silicate, sodium aluminate, iron (II) and iron (III) salts, polyacrylic acid salts, calcium chloride, calcium nitrate, calcium acetate, calcium nitrite, calcium formate, thiocyanate salts and triethanolamine. 
     
     
         3 . The system of  claim 1 , wherein the semi-permeable membrane is transparent to electromagnetic radiation. 
     
     
         4 . The system of  claim 1 , wherein the removable material comprises one or more members of aluminum metal, iron metal, zinc metal, nickel metal, tin metal, polylactic acid, polyglycolic acid, polyester and paraffin wax. 
     
     
         5 . A method for establishing zonal isolation in a subterranean wellbore having a formation wall, comprising:
 (i) inserting a zonal isolation system in the wellbore, the system comprising (a) at least one semi-permeable membrane; or (b) at least one semi-permeable membrane covered by a removable material; or (c) at least one opening covered by or filled with a removable material, or both; or (d) a combination thereof;   (ii) placing a cement slurry in the annular region between the outer surface of the tubular body and the formation wall; and   (iii) introducing a fluid inside the tubular body that comprises one or more activators.   
     
     
         6 . The method of  claim 5 , wherein the semi-permeable membrane is permeable to one or more activators in the list comprising sodium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium silicate, sodium aluminate, iron (II) and iron (III) salts, polyacrylic acid salts, calcium chloride, calcium nitrate, calcium acetate, calcium nitrite, calcium formate, thiocyanate salts and triethanolamine. 
     
     
         7 . The method of  claim 5 , wherein the activator concentration in the fluid is higher than about 10 weight percent. 
     
     
         8 . The method of  claim 5 , wherein the semi-permeable membrane is transparent to electromagnetic radiation. 
     
     
         9 . The method of  claim 5 , wherein the removable material comprises one or more members of aluminum metal, iron metal, zinc metal, nickel metal, tin metal, polylactic acid, polyglycolic acid, polyester and paraffin wax. 
     
     
         10 . The method of  claim 5 , wherein the pH of the fluid is lower than 7. 
     
     
         11 . The method of  claim 5 , wherein the fluid is a displacement fluid. 
     
     
         12 . The method of  claim 5 , wherein the fluid is introduced at one or more strategic locations in the tubular body. 
     
     
         13 . A method for cementing a subterranean wellbore having a formation wall, comprising:
 (i) inserting a zonal isolation system in the wellbore, the system comprising (a) at least one semi-permeable membrane; or (b) at least one semi-permeable membrane covered by a removable material; or (c) at least one opening covered by or filled with a removable material, or both; or (d) a combination thereof;   (ii) placing a cement slurry in the annular region between the outer surface of the tubular body and the formation wall; and   (iii) introducing a fluid inside the tubular body that comprises one or more activators.   
     
     
         14 . The method of  claim 13 , wherein the semi-permeable membrane is permeable to one or more activators in the list consisting of: sodium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium silicate, sodium aluminate, iron (II) and iron (III) salts, polyacrylic acid salts, calcium chloride, calcium nitrate, calcium acetate, calcium nitrite, calcium formate, thiocyanate salts and triethanolamine. 
     
     
         15 . The method of  claim 13 , wherein the activator concentration in the fluid is higher than about 10 weight percent. 
     
     
         16 . The method of  claim 13 , wherein the semi-permeable membrane is transparent to electromagnetic radiation. 
     
     
         17 . The method of  claim 13 , wherein the removable material is one or more members of the list comprising aluminum metal, iron metal, zinc metal, nickel metal, tin metal, polylactic acid, polyglycolic acid, polyester and paraffin wax. 
     
     
         18 . The method of  claim 13 , wherein the pH of the fluid is lower than 7. 
     
     
         19 . The method of  claim 13 , wherein the fluid is a displacement fluid. 
     
     
         20 . The method of  claim 13 , wherein the fluid is introduced at one or more strategic locations in the tubular body.