Patent ID: 7612023
Filing Date: 2009-11-03
Classification: C04B,C09K

Abstract:
1. A composition for treating cement surfaces in a subterranean well bore acidization zone, which composition consists of an aqueous mixture of 10 wt % acetic acid and 1.5 wt % hydrofluoric acid in a mutual solvent selected from the group consisting of ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol monopropyl ether, ethylene glycol and monoethyl ether and including one or more corrosion inhibitors selected from the group consisting of inorganic arsenic compounds, acetylenic alcohols, thiophenols, heterocyclic nitrogen compounds, substituted thioureas and rosin amines, the concentration of said acetic acid/hydrofluoric acid mixture being about 10% by volume, whereby said composition forms a protective acid-resistant barrier layer when it contacts downhole cement surfaces.