Curable cross-linkable compositions for use as lost circulation material

Abstract

The present invention relates to compositions and methods for reducing or preventing the loss of drilling fluids and other well servicing fluids into a subterranean formation during drilling or construction of boreholes in said formation. Specifically, this invention comprises a curable cross-linkable composition capable of free radical polymerization for creating lost circulation material. The curable cross-linkable composition comprises a mixture of (i) an organic compound capable of free radical (co)polymerization comprising a moiety derived from an diisocyanate and a moiety derived from an organic polyol comprising two or more hydroxyl groups having a molecular weight of from 400 to 4,000 and (ii) a reactive diluent comprising an organic compound with a reactive group and a moiety derived from an organic polyol comprising two or more hydroxyl groups having a molecular weight of from 60 to 500.

What is claimed is: 
     
         1 . A curable cross-linkable composition useful as a drilling well lost circulation material comprising:
 i from 40 to 90 weight percent of an organic compound capable of free radical (co)polymerization described by the following formula:   
       
         
           
           
               
               
           
         
         wherein: 
         x is an integer from 2 to 8; 
         L is a moiety comprising an aromatic or an aliphatic group derived from a diisocyanate wherein one of the isocyanate groups reacts with a reactive group on Fp 1  to form a first bond and the second isocyanate group reacts with a hydroxyl group on Q 1  to form a urethane link; 
         Fp 1  is a moiety derived from an organic compound with a reactive group and one or more free radical polymerizable group wherein the reactive group reacts with a first isocyanate group on L to form a first bond; 
         and 
         Q 1  is a moiety derived from a substituted or unsubstituted organic polyol comprising two or more hydroxyl groups wherein the moiety comprises an alkyl group, alkylene group, alkenyl group, cycloalkyl group, cycloalkylene group, aryl group, aralkyl group, alkaryl group, poly(oxyalkylene) group, poly(carboalkoxyalkylene) group, substituted heterocyclic group, or unsubstituted heterocyclic group wherein Q 1  has a molecular weight of from 400 to 4,000 and each hydroxyl group reacts with am isocyanate on an L to form a urethane link; 
         and 
         ii from 10 to 60 weight percent of a reactive diluent described by the following formula: 
       
       
         
           
           
               
               
           
         
         wherein: 
         y is an integer from 2 to 8; 
         Fp 2  is a moiety derived from an organic compound with a reactive group which reacts with a hydroxyl group on Q 2  to form a bond, Fp 2  comprises one or more free radical polymerizable group, and Fp 2  may be the same or different than Fp 1 ; 
         and 
         Q 2  is a moiety derived from a substituted or unsubstituted organic polyol comprising two or more hydroxyl groups wherein the moiety comprises an alkyl group, alkylene group, alkenyl group, cycloalkyl group, cycloalkylene group, aryl group, aralkyl group, alkaryl group, poly(oxyalkylene) group, poly(carboalkoxyalkylene) group, substituted heterocyclic group, or unsubstituted heterocyclic group wherein Q 2  has a molecular weight of from 60 to 500 each hydroxyl group reacts with the reactive group on an Fp2 to form a bond, Q 2  may the same or different than Q 1    
       
       wherein weight percent is based on the total weight of the curable cross-linkable composition. 
     
     
         2 . The curable cross-linkable composition of  claim 1  wherein said moieties comprising a free radical polymerizable group (Fp 1  and Fp 2 ) independently comprise a vinyl ether, a vinyl ester, an allyl ether, an allyl ester, a vinyl ketone, styrene, α-methylstyrene, a vinyl amide, an allyl amide, an acrylamide, a maleate, a fumarate, or a (meth)acrylate. 
     
     
         3 . The curable cross-linkable composition of  claim 1  wherein said moieties comprising a free radical polymerizable group (Fp 1  and Fp 2 ) are independently derived from a (meth)acrylate. 
     
     
         4 . The curable cross-linkable composition of  claim 1  wherein the bond connecting the organic compound with a reactive group (Fp 1 ) to the moiety (L) derived from a diisocyanate is a urethane link. 
     
     
         5 . The curable cross-linkable composition of  claim 1  wherein:
 i the polyvalent organic radical (Q 1 ) is derived from a polyethylene oxide polyol, a polypropylene oxide polyol, a polybutylene oxide polyol, a copolymer of polyalkylene oxide polyol, a terpolymer of polyalkylene oxide polyol, a polytetramethylene oxide polyol, a polyalkylene oxide based on a polyol, a polyester polyol, or a polycarbonate, 
 and 
 ii the polyvalent organic radical (Q 2 ) is derived from a polyhydroxyl compound. 
 
     
     
         6 . The curable cross-linkable composition of  claim 1  wherein:
 i the polyvalent organic radical (Q 1 ) is derived from a polyethylene oxide polyol or a polypropylene oxide polyol 
 and 
 ii the polyvalent organic radical (Q 2 ) is derived from ethylene glycol, trimethylol propane, 1,2 propylene glycol, glycerine, pentaerythritol, sorbitol, or sucrose. 
 
     
     
         7 . The curable cross-linkable composition of  claim 1  wherein the reactive diluent (ii) is trimethylolpropanetri(meth)acrylate, glycerine tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, triethyleneglycol dimethacrylate, ethyleneglycol dimethacrylate, tetraethyleneglycol dimethacrylate, polyethyleneglycol diacrylate, polyethyleneglycol dimethacrylate, 1,3-butyleneglycol dimethacrylate, trimethylol propane trimethacrylate, neopentylglycoldimethacrylate, ethoxylated Bisphenol A dimethacrylate, Bisphenol F dimethacrylate, propoxylated Bisphenol C dimethacrylate, Bisphenol A bis(2-hydroxy-propyl)dimethacrylate, butanediol di(meth)acrylate, or mixtures thereof. 
     
     
         8 . The curable cross-linkable composition of  claim 1  further comprises one or more initiator comprising a peroxide, a peroxy ester, a peroxy carbonate, a hydroperoxide, an alkylperoxide, an arylperoxide, an azo compound, or mixtures thereof. 
     
     
         9 . The curable cross-linkable composition of  claim 8  wherein the initiator comprises benzoyl peroxide, tert-butyl peroxide, dicumyl peroxide, hydrogen peroxide, diethyl peroxide, azobisisobutyronitrile, or mixtures thereof. 
     
     
         10 . The curable cross-linkable composition of  claim 8  wherein the one or more initiator is independently present in an amount equal to or greater than 0.1 weight percent and equal to or less than 10 weight percent based on the total weight of the curable cross-linkable composition. 
     
     
         11 . The curable cross-linkable composition of  claim 1  further comprises one or more inhibitor. 
     
     
         12 . The curable cross-linkable composition of  claim 11  wherein the one or more inhibitor is hydroquinone, butylated hydroxytoluene (BHT), butylated hydroxyaniline (BHA), 2-hydroxy-4-methoxy benzophenone (UV-9), methyl ethyl hydroquinone (MEHQ), 4-benzyloxy phenol, 3,5-diisopropyl phenol, or mixtures thereof. 
     
     
         13 . The curable cross-linkable composition of  claim 11  wherein the one or more inhibitor is independently present in an amount equal to or greater than 0.1 weight percent and equal to or less than 10 weight percent based on the total weight of the curable cross-linkable composition.