Methods for controlling depolymerization of polymer compositions
View Patent ↗A method of controlling or arresting the rate of depolymerization of a polymer composition during a biocide treatment, and use of such methods in oilfield and industrial applications. Also disclosed are methods of preparing a visco-stable application fluid containing a biocide in an amount effective to reduce bacteria count, as well as additive compositions capable of reducing bacteria count in application fluids while maintaining viscosity in such fluids. Also disclosed are methods of preparing biocide-containing application fluids with improved friction reducing properties, as well as related compositions.
1. An additive composition for use in oilfield application fluids consisting of:
a) a THP salt present in an amount from between about 5% to about 85% by weight of the composition;
b) a depolymerization inhibitor present in an amount between about 0.01% to about 50% by weight of the composition, the depolymerization inhibitor selected from hydroquinone, quinone, ascorbic acid, isoascorbic acid, thiol, glutathione, polyphenol, vitamin A, retinyl acetate, palmitate, alkylated monophenol, alkylthiomethylphenol, tocopherol, hydroxylated thiodiphenyl ether, an alkylidenebisphenol, an O-benzyl compound, an N-benzyl compound, an S-benzyl compound, hydroxybenzylated malonate, aromatic hydroxybenzyl compound, acylaminophenol or any combination thereof; and
c) one or more additives selected from:
(i) water;
(ii) a biocide different from the THP salt wherein the biocide is selected from quaternary ammonium compounds; polymeric quaternary ammonium compounds; polymeric biguanide hydrochlorides; tris(hydroxymethyl)nitromethane; 4,4-dimethylozazolidine; phenoxypropanol; phenoxyethanol; glyoxal; acrolein; aldehydes; triazines; quaternary phosphonium compounds; 2-bromo-4-hydroxyacetophenone; carbamates; tertbuthylazine; tetrachloro-2,4,6-cyano-3-benzonitrile; thiazole, isothiazole and derivatives thereof; compounds with activated halogen groups; bis chloromethyl sulphone; methylene bis thiocyanate; Na-p-toluensulfonchloroamide; sodium dichloro triazinetrione dehydrate; chloroamide; or any combination thereof; and
(iii) combinations thereof.
2. The additive of claim 1 wherein the THP salt is present in an amount from between about 20% to about 75% by weight of the composition.