Stabilization of High Molecular Weight Polysaccharide Solutions at High Temperatures

Abstract

A fluid mixture containing a high molecular weight polysaccharide composition with improved viscosity stability at high downhole temperatures and pressures encountered in common oil field applications, including hydraulic fracturing stimulation, drilling, cementing, and coil-tubing. The composition includes a salicylic acid solution, which, being a free-radical scavenger, prevents free-radical reactions within the high molecular weight polysaccharide that would otherwise adversely affect viscosity. The composition may also include an ascorbic acid solution, which reduces at least a portion of the oxidized salicylic acid to restore its function as a free-radical scavenger to prevent additional free-radical reactions with the high molecular weight polysaccharide. An alcohol solvent may also be utilized to increase the solution loading of salicylic acid.

Dependencies are inferred from the claim text.