Well servicing fluid and method of servicing a well with the fluid

摘要

Disclosed is a well servicing fluid for preventing the precipitation of calcium and magnesium in boreholes or wells after acid treatment, wherein the well servicing fluid comprises an aqueous based fluid comprising sulfate ions at a concentration greater than 50 mg/L (e.g., sea water); a chelating agent; and an acid in an amount sufficient to result in the well servicing fluid having a pH of 4.5 or less. In one embodiment the chelating agent is a polyphosphonic acid selected from the group consisting of diethylenetriaminepenta methylene phosphonic acid (DTPMPA) or bis(hexamethylene triamine penta) methylene phosphonic acid (BHMT). Also disclosed is a method of servicing a well using the well serving fluid.