Polymer Matrix Particles For Inhibitingscale Formation In Oil And Gas Wells

Abstract

Polymer matrix particles useful for inhibiting scale formation in oil and gas wells are described. The insoluble, porous, crosslinked polymer matrix includes a polymer backbone and ionic functional groups covalently bonded to the backbone, the ionic functional groups being capable of selectively attracting and binding salt scale-forming ions when in contact with a liquid containing such ions.

What is claimed is: 
     
         1 . Polymer matrix particles for inhibiting scale formation in oil and gas wells, each particle comprising a water-insoluble, porous, crosslinked polymer matrix, the polymer matrix comprising a polymer backbone and ionic functional groups covalently bonded to the backbone, the ionic functional groups being capable of selectively attracting and binding salt scale-forming ions when in contact with a liquid containing such ions. 
     
     
         2 . The polymer matrix particles of  claim 1 , wherein the particles have a tunable particle size. 
     
     
         3 . The polymer matrix particles of  claim 1 , wherein the polymer matrix has a tunable swelling characteristic. 
     
     
         4 . The polymer matrix particles of  claim 1 , wherein the crosslinking and porosity of the polymer matrix can be adjusted for tuning of structural rigidity and swelling behavior of the polymer matrix, and to achieve optimal ion transport into the polymer matrix. 
     
     
         5 . The polymer matrix particles of  claim 1 , wherein the polymer matrix has a degree of functionalization which is tunable to determine a thermodynamic equilibrium state of the particle and the liquid contacting the particle. 
     
     
         6 . The polymer matrix particles of  claim 1 , wherein the ionic functional groups are mono- or divalent cationic groups. 
     
     
         7 . The polymer matrix particles of  claim 1 , wherein the ionic functional groups are mono- or divalent anionic groups. 
     
     
         8 . The polymer matrix particles of  claim 1 , wherein the ionic functional groups are capable of selectively binding halite-forming ions. 
     
     
         9 . The polymer matrix particles of  claim 8 , wherein the ionic functional groups are monovalent cationic groups capable of selectively binding halide ions. 
     
     
         10 . The polymer matrix particles of  claim 9 , wherein the monovalent cationic groups are quaternary ammonium groups. 
     
     
         11 . The polymer matrix particles of  claim 9 , wherein the halide ions are chloride ions. 
     
     
         12 . The polymer matrix particles of  claim 8 , wherein the ionic functional groups are monovalent anionic groups capable of selectively binding sodium ions. 
     
     
         13 . The polymer matrix particles of  claim 12 , wherein the monovalent anionic groups are sulfonate groups. 
     
     
         14 . The polymer matrix particles of  claim 1 , wherein the particles are regular in shape. 
     
     
         15 . The polymeric matrix particles of  claim 1 , wherein the polymer backbone of the polymer matrix is selected from the group consisting of polyacrylates, polyurethanes, polyesters and polystyrenes. 
     
     
         16 . The polymeric matrix particles of  claim 1 , wherein the polymer matrix has a polyacrylate backbone, and wherein the ionic functional groups are quaternary ammonium groups capable of selectively binding chloride ions. 
     
     
         17 . A suspension for inhibiting scale formation in oil and gas wells, the suspension comprising polymer matrix particles suspended in an aqueous medium, each particle comprising a water-insoluble, porous, crosslinked polymer matrix, the polymer matrix comprising a polymer backbone and ionic functional groups covalently bonded to the backbone, the ionic functional groups being capable of selectively attracting and binding salt scale-forming ions when in contact with a liquid containing such ions. 
     
     
         18 . The suspension of  claim 17  wherein the ionic functional groups are capable of selectively binding halite-forming ions. 
     
     
         19 . The suspension of  claim 18  wherein the ionic functional groups are monovalent cationic groups capable of selectively binding halide ions. 
     
     
         20 . A method of inhibiting scale formation in an oil or gas well comprising: injecting polymer matrix particles into an oil or gas well, so that the polymer matrix particles come into contact with a liquid containing salt scale-forming ions, each polymer matrix particle comprising a water-insoluble, porous, crosslinked polymer matrix, the polymer matrix comprising a polymer backbone and ionic functional groups covalently bonded to the backbone, the ionic functional groups contacting the liquid and selectively attracting and binding the salt scale-forming ions. 
     
     
         21 . The method of  claim 20  wherein the polymer matrix particles are injected in the form of a suspension of the particles in an aqueous medium. 
     
     
         22 . The method of  claim 20  wherein the liquid containing the salt scale-forming ions is a brine. 
     
     
         23 . The method of  claim 20  wherein the ionic functional groups selectively bind halite-forming ions. 
     
     
         24 . A method of inhibiting scale formation in an oil or gas well comprising:
 (a) injecting a suspension of polymer matrix particles into an oil or gas well, so that the polymer matrix particles come into contact with a liquid containing salt scale-forming ions, each polymer matrix particle comprising a water-insoluble, porous, crosslinked polymer matrix, the polymer matrix comprising a polymer backbone and ionic functional groups covalently bonded to the backbone, the ionic functional groups contacting the liquid and selectively attracting and binding the salt scale-forming ions; and then   (b) separating the polymer matrix particles after they have bound the salt scale-forming ions.   
     
     
         25 . The method of  claim 24 , wherein the polymer matrix particles are separated by filtration or gravimetrically. 
     
     
         26 . The method of  claim 24 , further comprising regenerating the polymer matrix particles after they are separated by removing the bound salt scale-forming ions. 
     
     
         27 . The method of  claim 26 , wherein the polymer matrix particles are regenerated by using a controlled pH buffer to displace the salt scale-forming ions from the particles. 
     
     
         28 . The method of  claim 24 , wherein the liquid containing the salt scale-forming ions is a brine. 
     
     
         29 . A coating for application to an interior surface of an oil or gas well to inhibit scaling, the coating comprising:
 a continuous phase suitable for forming a coating on an interior surface of a well; and   polymer matrix particles dispersed in the continuous phase for inhibiting scale formation, each particle comprising a water-insoluble, porous, crosslinked polymer matrix, the polymer matrix comprising a polymer backbone and ionic functional groups covalently bonded to the backbone, the ionic functional groups being capable of selectively attracting and binding salt scale-forming ions when in contact with a liquid containing such ions; and   optionally, another treatment chemical useful in an oil or gas well.