An aqueous acid composition that may be used, for example, in a matrix acidizing treatment can include an acid, a polymeric acid corrosion inhibitor, and an acid corrosion inhibitor intensifier. The acid corrosion inhibitor can include iodide ions and metal ions, with the metal ions being one or more of copper, silver, bismuth, or antimony. The molar ratio of metal ions to iodide ions can be 1:X, where X is greater than or equal to 2. The polymer of the polymeric acid corrosion inhibitor can have a molecular weight less than 100,000 g/mol.