CATIONIC VISCOELASTIC SURFACTANT WITH NON-CATIONIC CORROSION INHIBITOR AND ORGANIC ANION FOR ACIDIZING

摘要

A treatment fluid and method treating a zone of a subterranean formation penetrated by a wellbore. The treatment fluid includes: (i) water; (ii) a strong acid; (iii) a cationic viscoelastic surfactant; (iv) an anionic organic component having at least 4 carbon atoms; and (v) a non-cationic corrosion inhibitor; wherein the pH of the treatment fluid is less than 0.5. Preferably, the viscosity of the treatment fluid is less than 5 cP at 40 sec-1. The method includes the steps of: (A) forming the treatment fluid; (B) introducing the treatment fluid through the wellbore into the zone; and (C) allowing time for the strong acid in the treatment fluid to spend in the formation. Preferably, as the acid spends in the subterranean formation, the viscosity of the treatment fluid increases in the well to above 5 cP. Such a treatment fluid shows good rheological properties at temperatures above 93° C. (200° F.).