The sodium salts of 1,4-di-n-butylbenzene-, 1,4-di-n-pentylbenzene-, 1,4-di-n-hexylbenzene- and 1,4-di-n-octylbenzene sulphonates were prepared and evaluated, on a laboratory scale, for enhanced oil recovery (EOR) formulation systems. Krafft-Clear Point Diagrams, for the aqueous solutions of these sulphonates, in presence of added electrolyte and/or alcohols, were drawn. The study revealed that the most distinctive property of 1,4-di-n-alkylbenzene sulphonates which sets them apart from the corresponding 1-phenyl-n-alkane sulphonates having the same molecular weight, is their low Krafft points in presence of the same electrolyte and/or alcohol concentrations.