Branched viscoelastic surfactant for high-temperature acidizing

Abstract

A treatment fluid for use in a subterranean formation penetrated by the wellbore of a well includes: (i) water; (ii) a strong acid; and (iii) a branched viscoelastic surfactant having a hydrophobic portion with a total of 16 to 20 carbons; wherein the pH of the treatment fluid is less than 0.5; and wherein the viscosity of the treatment fluid is less than 5 cP at 40 sec-1. A method of treating a zone of a subterranean formation penetrated by a wellbore includes the steps of forming the treatment; (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. Such a treatment fluid shows good rheological properties at temperatures above 93° C. (200° F.).

Dependencies are inferred from the claim text.