High concentration surfactant compositions and methods

A pourable, pumpable, high concentration, aqueous, liquid surfactant composition consisting of:

• (a) at least one surfactant selected from the group consisting of an amphoteric surfactant and an anionic surfactant;
• (b) at least about 0.1% by weight on a total composition weight basis of at least one liquid-stabilizing agent selected from the group consisting of a compound of formula (I) and a salt thereof;
• wherein A is —NH(R1), —N(R1)(R2), or —NHCOY;
• R1 and R2 are each independently —(CH2)n—OH, —(CH2)n—SO3H, —(CH2)n—PO3H2, —(CH2) n—COOH, or —CH(R3)—COOH;
• R3 is —CH2OH, —CH(CH3)—OH, —CH2SH, —CH2CONH2, —CH2CH2CONH2, —CH2COOH, or —CH2CH2COOH;
• Y is saturated or unsaturated C1-C30 alkyl;
• n is an integer in the range of about 2 to about 6;
• and m is 1 or 2;
• (c) optionally an alkali metal halide salt;
• and
• (d) water;
• wherein the surfactant is present in the high concentration, aqueous, liquid surfactant composition in a concentration of at least about 25% by weight, and the liquid-stabilizing agent is present in an amount of not more than about 10% by weight, on a total composition weight basis, and wherein the composition is non-liquid in the absence of the liquid stabilizing amount of the liquid stabilizing agent at an ambient temperature of about 20° C.