Multi-Layer Water Swelling Packer

Abstract

A packer for downhole use responds to water containing fluids by swelling from its core. The core is preferably covered with an outer layer that preferably has a lower rate of diffusion and swelling than the core that it surrounds. Because of this arrangement, the packer can be delivered to the desired location before it is set by swelling of the core. The outer layer can also be responsive to water containing fluids by dissolving slowly to allow time to properly position the packer before the core swells to a sealing relationship with the surrounding tubular or the wellbore wall.

1 . A packer for downhole use, comprising:
 a mandrel;   a multi-component element wherein a first component, having a cohesive shape supported by said mandrel, swells responsive to water containing fluid and a second component controls access of water containing fluids to said first component.   
   
   
       2 . The packer of  claim 1 , wherein:
 said second component is mounted over said first component.   
   
   
       3 . The packer of  claim 2 , wherein:
 said second component allows water containing fluid to diffuse through it.   
   
   
       4 . The packer of  claim 3 , wherein:
 said second component has openings.   
   
   
       5 . The packer of  claim 1 , wherein:
 said second component dissolves in the presence of water containing fluids.   
   
   
       6 . The packer of  claim 1 , wherein:
 said first component is made of an elastomeric polymer material or acrylate, acetate or formate salts.   
   
   
       7 . The packer of  claim 6 , wherein:
 said material further comprises acrylonitrile, nitrile, hydrogenated nitrile, chloroprene, ethylene vinyl acetate, ethylene propylene diene monomer, ethylene propylene, or polynorbornen and acrylic copolymer, super absorbent polymers (SAP), carboxy methyl cellulose or/and a partially modified or fully cross-linked acrylic polymer added.   
   
   
       8 . The packer of  claim 1 , wherein:
 said second component is made of an elastomeric polymer material or acrylate, acetate or formate salts.   
   
   
       9 . The packer of  claim 8 , wherein:
 said material further comprises acrylonitrile, nitrile, hydrogenated nitrile, chloroprene, ethylene vinyl acetate, ethylene propylene diene monomer, ethylene propylene, or polynorbornen with an acrylic copolymer added.   
   
   
       10 . The packer of  claim 1 , wherein:
 said second component swells less than said first component.   
   
   
       11 . The packer of  claim 1 , wherein:
 said second component diffuses water containing fluids at a slower rate than said first component.   
   
   
       12 . The packer of  claim 10 , wherein:
 said first component comprises an annular cylindrical shape disposed around said mandrel.   
   
   
       13 . The packer of  claim 12 , wherein:
 said second component covers substantially the entire outer surface of said first component.   
   
   
       14 . The packer of  claim 11 , wherein:
 said first component comprises an annular cylindrical shape disposed around said mandrel.   
   
   
       15 . The packer of  claim 14 , wherein:
 said second component covers substantially the entire outer surface of said first component.   
   
   
       16 . The packer of  claim 10 , wherein:
 said second component diffuses water containing fluids at a slower rate than said first component.