Patent ID: 7521400
Filing Date: 2009-04-21
Classification: C09K

Abstract:
1. A viscoelastic gelled fluid comprising a non-aqueous base oil, a gelling agent comprising an organic phosphate, an activator, and a gel-enhancing viscoelastic surfactant that increases the viscosity of the fluid in a concentration range of from 0.02 to 1.6 volume percent, wherein the gel-enhancing surfactant comprises a quaternary amine having the formula: in which R is an alkyl group that contains from about 17 to about 23 carbon atoms which may be branched or straight chained and which may be saturated or unsaturated; a, b, a', and b'are each from 0 to 10 and m and m' are each from 0 to 13; a and b are each 1 or 2 if m is not 0 and (a+b) is from 2 to 10 if m is 0; a' and b' are each 1 or 2 when m' is not 0 and (a'+b') is from 1 to 5 if m is 0; (m+m') is from 0 to 14; and CH 2 CH 2 O may also be OCH 2 CH 2 .