Fluid Loss Control Additive and Cement Compositions Comprising Same

Abstract

A fluid loss control additive comprising a crosslinked polymer and sugar and cement compositions comprising the same. In one embodiment, the fluid loss control additive comprises a polymer and a sugar connected by a pH-sensitive crosslink. In some embodiments, the polymer is a polyvinyl alcohol, and the sugar is a sugar alcohol such as sorbitol.

1 . A fluid loss control additive comprising a polymer and a sugar connected by a pH-sensitive crosslink. 
     
     
         2 . The fluid loss control additive of  claim 1 , wherein the fluid loss control additive comprises a weight ratio of polymer to sugar of from about 1:3 to about 10:1. 
     
     
         3 . The fluid loss control additive of  claim 1 , wherein the pH-sensitive crosslink is achieved through a polyvalent cation. 
     
     
         4 . The fluid loss control additive of  claim 3 , wherein the polyvalent cation comprises a Group IIIA element or a Group IVB element. 
     
     
         5 . The fluid loss control additive of  claim 3 , wherein the polyvalent cation comprises boron. 
     
     
         6 . The fluid loss control additive of  claim 3 , wherein the fluid loss control additive contains the polyvalent cation in the amount of from about 0.001 to about 5 percent by weight of the polymer. 
     
     
         7 . The fluid loss control additive of  claim 1 , wherein the pH-sensitive crosslink comprises a borate ester. 
     
     
         8 . The fluid loss control additive of  claim 1 , wherein the fluid loss control additive is biodegradable. 
     
     
         9 . The fluid loss control additive of  claim 1 , wherein the sugar is a sugar alcohol. 
     
     
         10 . The fluid loss control additive of  claim 9 , wherein the sugar alcohol comprises sorbitol, maltitol, isomalt, xylitol, lactitol, hydrogenated starch hydrolysate, or combinations thereof. 
     
     
         11 . The fluid loss control additive of  claim 9 , wherein the sugar alcohol comprises sorbitol. 
     
     
         12 . The fluid loss control additive of  claim 1 , wherein the polymer comprises a polyalcohol, an alpha hydroxy acid, a 1,2 amine, or combinations thereof. 
     
     
         13 . The fluid loss control additive of  claim 1 , wherein the polymer comprises polyvinyl alcohol. 
     
     
         14 . The fluid loss control additive of  claim 1 , wherein the fluid loss control additive is an emulsion further comprising a carrier fluid. 
     
     
         15 . The fluid loss control additive of  claim 14 , wherein the carrier fluid is a hydrophobic carrier fluid. 
     
     
         16 . The fluid loss control additive of  claim 14 , wherein the fluid loss control additive comprises from about 1 to about 90 wt. % carrier fluid. 
     
     
         17 . The fluid loss control additive of  claim 5 , wherein the sugar comprises sorbitol. 
     
     
         18 . The fluid loss control additive of  claim 5 , wherein the polymer comprises polyvinyl alchohol. 
     
     
         19 . The fluid loss control additive of  claim 17 , wherein the polymer comprises polyvinyl alchohol. 
     
     
         20 . A fluid loss control additive comprising polyvinyl alcohol and sorbitol connected by a polyvalent boron cation, wherein the fluid loss control additive is effective to control the loss of fluid from a cementitious wellbore servicing fluid. 
     
     
         21 . The fluid loss control additive of  claim 20 , wherein a ratio of polyvinyl alcohol to sorbitol is from about 1:3 to about 10:1. 
     
     
         22 . The fluid loss control additive of  claim 21 , further comprising a vegetable oil forming an emulsion.