HCl — Oil & Gas Glossary

(noun) Chemical formula for hydrochloric acid. A strong mineral acid widely used in well stimulation and matrix acidising to dissolve carbonate formations, remove scale deposits, and improve near-wellbore permeability. HCl is typically pumped downhole at concentrations of 15% to 28% by weight, often combined with corrosion inhibitors and other additives to protect tubulars.