摘要 |
Viscosifiers for addition to high zinc salt brines, used as oil well workover and completion fluids, are prepared from natural polysaccharide gums by treatment with a basic nitrogen reagent, such as a quaternary ammonium compound, hexamethylene tetramine, or dimethylol urea. The treated viscosifiers have improved dispersibility and give increased viscosity effects in the brines. Preferably, the viscosifiers are prepared from carrageenan or locust bean gums.
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