Hydrogel for use in downhole seal applications

Abstract

The present invention is a composition for forming seals. The composition includes a base material and a hydrogel. The base material is preferably an elastomer or a thermoplastic. Seals formed with the composition are particularly suited for use in a wellbore environment. The inclusion of hydrogel in the seals allows the seals to be manipulated or altered through certain environmental factors. For instance, temperature, oil/water ratio, pH and the electronic field may all be used to alter the characteristics of the hydrogel. In this way, the seal may be caused to swell in response to a specific stimulus, thereby preventing or sealing a leak without requiring additional work or input from the operator.

1 . A composition for forming a swellable wellbore seal body comprising: 
 a. base material, and    b. a hydrogel,    whereby the seal body is placed in a wellbore to form a seal which isolates a particular wellbore zone from another wellbore zone or region of a subterranean formation.    
   
   
       2 . The composition of  claim 1  wherein the hydrogel is incorporated in an amount from about 10 parts by weight to about 90 parts by weight based upon 100 parts of the base material.  
   
   
       3 . The composition of  claim 2  wherein the hydrogel is incorporated in an amount from about 20 parts by weight to about 70 parts by weight based upon 100 parts of the base material.  
   
   
       4 . The composition of  claim 1 , wherein the base material is a polymer.  
   
   
       5 . The composition of  claim 4 , wherein the elastomer is selected from the group consisting of nitrile rubber, hydrogenated nitrile rubber, carboxyl nitrile rubber, silicon rubber, ethylene-propylene-diene copolymers, fluoroelastomers and perfluoroelastomers.  
   
   
       6 . The composition of  claim 4  wherein the polymer is a thermoplastic selected from the group consisting of Teflon®, polyetheretherketone, polypropylene, polystyrene and polyphenylene sulfide.  
   
   
       7 . The composition of  claim 1  wherein the hydrogel is selected from the group consisting of: methylcellulose, cellulose acetate pthalate and hydroxypropyl methylcellulose polymers, poly (ethylene oxide) polymers, guar, derivatized guar, polyacrylamide, polyvinylpyrolidone, copolymers of maleinate oligomers and allyl maleate oligomers, silicon-based polymers and fluorosilicone-based polymers.  
   
   
       8 . The composition of  claim 1  wherein the hydrogel is a metal complex of a polymer selected from the group consisting of: methylcellulose, cellulose acetate pthalate and hydroxypropyl methylcellulose polymers, poly (ethylene oxide) polymers, guar, derivatized guar, polyacrylamide, polyvinylpyrolidone, copolymers of maleinate oligomers and allyl maleate oligomers, silicon-based polymers and fluorosilicone-based polymers.  
   
   
       9 . A seal body for use in a wellbore comprising the composition of  claim 1 .  
   
   
       10 . The composition of  claim 1 , wherein said seal body is an o-ring, a t-seal body, a chevron seal body, a spring seal body, a packer element, a gasket, or a bridge plug.  
   
   
       11 . A swellable wellbore seal body comprising: 
 a. base material, and    b. a hydrogel,    wherein the seal body is deployed into a wellbore in a first configuration, and wherein the seal changes to a second configuration upon exposure to a factor, thereby forming a seal isolating a particular wellbore zone from another wellbore zone or region of a subterranean formation.    
   
   
       12 . The seal body of  claim 1  wherein the first configuration is an unset configuration and the second configuration is a set configuration.  
   
   
       13 . The seal body of  claim 11  wherein the seal body changes to a third configuration upon exposure to another factor.  
   
   
       14 . The seal body of  claim 13  wherein the third configuration is the same as the first configuration.  
   
   
       15 . The seal body of  claim 11  wherein the seal body changes to a third configuration upon removal of the factor.  
   
   
       16 . The seal body of  claim 15  wherein the third configuration is the same as the first configuration.  
   
   
       17 . The composition of  claim 11 , wherein said seal body is an o-ring, a t-seal body, a chevron seal body, a spring seal body, a packer element, a gasket, or a bridge plug.  
   
   
       18 . A method for forming a seal in a wellbore comprising: 
 a. providing swellable wellbore seal body comprising a base material, and a hydrogel,    b. deploying the seal body into a wellbore in a first configuration, and,    c. exposing the seal body to a factor causing the seal to change to a second configuration upon exposure to a factor,    thereby forming a seal isolating a particular wellbore zone from another wellbore zone or region of a subterranean formation.    
   
   
       19 . The method of  claim 18  wherein the deploying step comprises deploying the seal in a first unset configuration and the exposing step causes a second configuration which is a set configuration.  
   
   
       20 . The method of  claim 18  further comprising exposing the seal body to a second factor to change the seal body to a third configuration.  
   
   
       21 . The method of  claim 18  further comprising exposing the seal body to a second factor to change the seal body to the first configuration.  
   
   
       22 . The method of  claim 18  further comprising removing factor to change the seal body to the first configuration.  
   
   
       23 . The method of  claim 18  wherein said seal body is an o-ring, a t-seal body, a chevron seal body, a spring seal body, a packer element, a gasket, or a bridge plug.