| abstract |
Processes are disclosed for activating hydroxyethyl cellulose (HEC) such that the HEC will disperse and hydrate in compatible heavy brines having a density greater than about 13.5 pounds per gallon containing one or more salts selected from the group consisting of calcium chloride, calcium bromide, zinc chloride, and zinc bromide, at ambient temperatures such that the HEC will be at least 80% hydrated within one hour. The activation process comprises admixing the HEC with an organic liquid which has no appreciable swelling effect on the HEC and an amine activator. The invention also provides activated HEC compositions and a process of increasing the viscosity of a heavy brine utilizing these compositions. |