Well Treatment

Abstract

The following describes a novel and alternative mechanism in regards to releasing reactive chemicals. Namely, utilizing shells containing multiple emulsions that can be blended with the base fluids, and then react with said base fluid upon exposure to a trigger e.g. high shear and/or elongation flow, therefore plugging even large fractures. Such gelling lost circulation material allows to obtain a reliable carrier and fast reaction when triggered.

1 . A gelling lost circulation material (LCM) comprising a carrier fluid containing polymerizable compounds; the gelling LCM further comprising shells having drops of accelerator contained therein; characterized in that the LCM further comprises a polymerization initiator. 
     
     
         2 . The LCM of  claim 1 , wherein the carrier fluid is a water-soluble or water-dispersible monomers. 
     
     
         3 . The LCM of  claim 1 , wherein the shells are made from polyurethane. 
     
     
         4 . The LCM of  claim 1 , wherein the initator is present in the carrier fluid. 
     
     
         5 . The LCM of  claim 1 , wherein the accelerator is contained with the droplets of accelerator. 
     
     
         6 . The LCM according to  claim 1 , wherein the polymerizable compounds comprise an acrylated or methacrylated poly-oxyethylene and/or poly-oxypropylene monomer. 
     
     
         7 . The LCM according to  claim 1 , wherein the water-soluble or water-dispersable monomer is of the general formula:
   CH 2 ═CR 1 —CO—(O—CH 2 —CHR 2 ) n —OR 3   (I)
   
       Wherein: 
       Ris a hydrogen atom or a methyl radical, 
       R 2  is a hydrogen atom or a methyl radical, and 
       R 3  is a hydrogen atom, a methyl radical, or a CH 2 ═CR 1 —CO— group. 
       n is a whole or fractional number from 3 to 25. 
     
     
         8 . The LCM according to  claim 1 , wherein the dispersible monomers is a mixture of methacrylated modified poly-oxyethylene oxide of the formula: 
       
         
           
           
               
               
           
         
       
       Wherein n is a number between 15 and 25, limits included, and/or 
       
         
           
           
               
               
           
         
       
       Wherein n is a number between 10 and 20, limits included, and/or. 
     
     
         9 . The LCM of  claim 1 , wherein the water soluble or water dispersable monomers used in the composition of the invention is a mixture comprising at least two distinct kinds of monomers, obtained by reacting a mixture of two compounds (A1) and (A2) having the following formula:
   HO—(O—CH 2 —CHR 2 ) n —OMe  (A1)
     HO—(O—CH 2 —CHR 2 ) n —OH  (A2)
   
       wherein R 2  is as defined in claim  14 , 
       with a (meth)acrylic acid, chloride or anhydride, typically a (meth)acrylic anhydride of formula (CH 2 ═C R 1 —C) 2 O wherein R 1  is as defined in claim  14 , 
       preferably with a molar ratio (A2):(A1) of between 10:90 to 50:50.