Patent ID: 8399386

Claim:
A method of foaming a fluid and unloading the fluid from an oil or gas well, the method comprising: (A) introducing into the fluid at the downhole end of the oil or gas well a foam-forming amount of a composition comprising at least one imidazoline-based compound of the general formula: wherein, R 4 has the following structure: (i) R 1 is a moiety selected from the group consisting of: substituted or unsubstituted branched, chain, or ring alkyl or alkenyl having from 5 to about 29 carbon atoms in its main chain; (ii) each R 2 is independently hydrogen or a linear alkyl or alkenyl moiety having from 1 to about 10 carbon atoms; (iii) each R 3 is independently a moiety selected from the group consisting of: —CO 2 H, —SO 3 H, —PO 3 H 2 , —CO 2 R 5 , —CONH 2 , —CONHR 5 , —CON(R 5 ) 2 , and combinations thereof; (iv) at least one R 6 is R 4 , and the other R 6 is H or R 4 ; (v) each R 5 is independently a moiety selected from the group consisting of: hydrogen, substituted and unsubstituted linear alkyl, branched alkyl, aryl, alkylaryl, cycloalkyl, and heteroaromatic groups having from 1 to about 10 carbon atoms in the main chain; (vi) n is from 0 to about 8; (vii) each o is independently from 0 to about 10; (viii) x is 0 or 1; and (ix) y is from 0 to about 4 wherein a method of monitoring foaming rates is used to decide an effective foam-forming amount of the composition to introduce into the fluid; (B) forming a foam comprising the fluid and the composition; and (C) recovering the foam from the well.