Carboxymethyl cellulose solution compatibility

The most widely used synthetic and natural enhanced oil recovery polymers, such as partially hydrolyzed polyacrylamide, carboxymethyl(ethyl) cellulose, polysaccharides, or xanthan gums, are not suitable for high-temperature reservoirs (> 90 °C) with high-density brine fluid due to excessive hydrolysis and precipitation [277]. The main advantages of polymeric betaines over the mentioned standard polymers are (1) thermostability (up to 120 °C) (2) brine compatibility and (3) viscosification in brine solution [278]. Carbobetaines grafted onto hydroxyethyl cellulose were tested as a drilling-mud additive for clay hydration inhibition and mud rheological control [279]. An increase in the content of carbobetaine moieties resulted in an enhanced inhibitive abiUty, especially for sahne mud. 

SAF Safronov, A.P., Tyukova, I.S., and Suvorova, A.I., The nature of thermodynantic compatibility of components of aqueous solutions of starch and cellulose carboxymethyl derivatives, Polym. Sci., Ser. A, 51, 174, 2009. 

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