摘要 |
Disclosed are a process for the preparation of pseudoplastic, shear thinning chitosan-containing fluids, and a method of enhancing the thermal stability of such fluids. Pseudoplastic fluids useful oil and/or gas wells, particularly drilling fluids, drill-in fluids, workover fluids, completion fluids, perforating fluids, filter cake removal fluids, various pills, and the like, are prepared by solublizing chitosan in an acidic solution and thereafter raising the pH above about 7.0 by the addition of a basic compound thereto. The thermal stability of such fluids is enhanced by incorporating into the fluids certain aldose or ketose sugars, oligosaccharides of such sugars, and mixtures thereof, optionally together with a water soluble bisulfite compound.
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