Self-diverting acid treatment with formic-acid-free corrosion inhibitor

Abstract

A method of treating a subterranean formation penetrated by a wellbore of a well having iron-containing components is carried out by introducing a treatment fluid into the wellbore of the well. The treatment fluid is formed from an aqueous solution, a mineral acid, a viscoelastic surfactant gelling agent and corrosion inhibitor system containing at least one of an alkyl, alkenyl, alycyclic or aromatic substituted aliphatic ketone and aliphatic or aromatic aldehyde. The treatment fluid is substantially free of any formic acid or precursor formic acid. In certain embodiments, the corrosion inhibitor system comprises a mixture of at least one of an alkenyl phenone or α, β-unsaturated aldehyde, an unsaturated ketone or unsaturated aldehyde other than the alkenyl phenone and α, β- unsaturated aldehyde, a dispersing agent, an extender and an alcohol solvent. A corrosion inhibitor intensifier may also be used in certain embodiments,' which may include a mixture of cuprous iodide and cuprous chloride.