Patent ID: 11441064

Abstract:
A method of removing iron-containing scale from a wellbore, pipe, or metal-containing surface involving contacting the iron-containing scale with a biodegradable descaler solution of water, hydrochloric acid, formic acid, citric acid, a corrosion inhibitor, a corrosion inhibitor intensifier, and a surfactant. The method is performed at a pressure of 14 to 400 psi and a temperature of 100 to 150° C. The method removes iron-containing scale made of iron sulfide, iron carbonate, iron oxyhydroxide, and calcium carbonate. The method meets industry standard steel corrosion rates of less than 0.049 lb/ft2 per day. Also disclosed is a biodegradable descaler solution of water, hydrochloric acid, formic acid, citric acid, a corrosion inhibitor, a corrosion inhibitor intensifier, and a surfactant that meets OECD 301B thresholds for ready biodegradability.