Downwell system with activatable swellable packer

Abstract

A packer system for a wellbore includes a tubular member and a packer element having an inner layer that circumferentially overlies the tubular member and an outer layer that circumferentially overlies the inner layer. The inner layer includes an elastomer that swells upon contact with a swelling fluid. The outer layer includes a material that provides at least a partial barrier to the swelling fluid.

1 . A packer system for a wellbore, comprising:
 a tubular member; and   a packer element having an inner layer that circumferentially overlies the tubular member and an outer layer that circumferentially overlies the inner layer;   wherein the inner layer comprises an elastomer that swells upon contact with a swelling fluid; and   wherein the outer layer comprises a material that provides at least a partial barrier to the swelling fluid.   
     
     
         2 . The packer system defined in  claim 1 , wherein the outer layer comprises a material that is substantially impermeable to the swelling fluid, and is dissolvable in an non-naturally occurring activation fluid. 
     
     
         3 . The packer system defined in  claim 2 , wherein the material of the outer layer is dissolvable in acid having a pH of less than about 5.0. 
     
     
         4 . The packer system defined in  claim 2 , wherein the outer layer comprises an organic coating. 
     
     
         5 . The packer system defined in  claim 2 , wherein the outer layer comprises an inorganic coating. 
     
     
         6 . The packer system defined in  claim 2 , wherein the material of the outer layer is dissolvable in a base. 
     
     
         7 . The packer system defined in  claim 1 , wherein the outer layer comprises a material that is partially permeable to the swelling fluid. 
     
     
         8 . The packer system defined in  claim 1 , wherein the outer layer comprises a material that is degradable in water or hydrocarbon. 
     
     
         9 . The packer system defined in  claim 1 , wherein the elastomer of the inner layer comprises a rubber material. 
     
     
         10 . The packer system defined in  claim 1 , wherein the elastomer of the inner layer comprises EPDM. 
     
     
         11 . The packer system defined in  claim 1 , further comprising centralizing end caps fixed to the tubular member and mounted adjacent opposed axial ends of the packer element. 
     
     
         12 . The packer system defined in  claim 11 , wherein the end caps have a first radius, the outer layer has a second radius, and the first radius is greater than the second radius. 
     
     
         13 . The packer system defined in  claim 11 , wherein the end caps comprise a polymer composite material. 
     
     
         14 . A packer system for a wellbore, comprising:
 a tubular member; and   a packer element having an inner layer that circumferentially overlies the tubular member and an outer layer that circumferentially overlies the inner layer;   wherein the inner layer comprises an elastomer that swells upon contact with a swelling fluid; and   wherein the outer layer comprises a material that provides at least a partial barrier to the swelling fluid; and   centralizing end caps mounted to the tubular member adjacent opposite ends of the packer element.   
     
     
         15 . The packer system defined in  claim 14 , wherein the end caps have a first radius, the outer layer has a second radius, and the first radius is greater than the second radius. 
     
     
         16 . The packer system defined in  claim 14 , wherein the end caps comprise a polymer composite material. 
     
     
         17 . A method of isolating a first section of a wellbore from a second section, comprising:
 providing a packer system having a tubular member and a packer element, the packer element including an inner layer that circumferentially overlies the tubular member and an outer layer that circumferentially overlies the inner layer, the inner layer comprising an elastomer that swells upon contact with a swelling fluid, the outer layer comprising a material that provides at least a partial barrier to the swelling fluid;   positioning the packer system in a wellbore;   penetrating the outer layer to enable the inner layer to contact the swelling fluid; and   permitting the inner layer to swell sufficiently to contact walls of the wellbore, thereby isolating at least the first section of the wellbore from the second section of the wellbore.   
     
     
         18 . The method defined in  claim 17 , wherein the step of penetrating the outer layer comprises removing the outer layer. 
     
     
         19 . The method defined in  claim 18 , wherein the step of removing the outer layer comprises dissolving the outer layer with a non-naturally occurring fluid. 
     
     
         20 . The method defined in  claim 18 , wherein the non-naturally occurring fluid comprises an acid having a pH of less than about 5.0. 
     
     
         21 . The method defined in  claim 18 , wherein the step of removing the outer layer comprises removing the outer layer with one of water and hydrocarbon present in the wellbore. 
     
     
         22 . The method defined in  claim 17 , wherein the outer layer is partially permeable to the swelling fluid, and wherein the step of penetrating the outer layer comprises passing the swelling fluid through the outer layer.