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Abstract

A method of solubilizing/removing cellulose or chemically-modified cellulosic polymers utilized in subterranean drilling operations such as fracturing. The method involves introducing a deep eutectic solvent (DES) into a subterranean region. Deep eutectic solvents useful as cellulose solvents include quaternary ammonium compounds, including choline chloride and chlorcholine chloride, reacted with a compound selected from amides, amines, carboxylic acids alcohols, and metal halides. The DES material can be pumped downhole after fracturing operations to remove cellulosic material used, for example, to thicken fracturing fluid which is left behind in the created fractures, on the face of the formation, along the wellbore, or elsewhere within the subterranean region. The DES can be used alone or in a sequential treatment protocol, whereby the DES is introduced into the subterranean region, followed by post-treatment introduction of water, caustic, acid or anhydride into the subterranean as a flush.

First Claim