Some crude oils react with acid to form a black asphaltic sludge by the coagulation of unstable colloidal material in the oil. The sludge is a mixture of asphaltic compounds, resins, paraffins and other high-molecular weight constituents of crude oil. Sludge can stabilize emulsions; cause plugging of pore spaces and may be responsible for the poor performance of matrix treatments in some reservoirs.

JKN-KSZ is used in acid fluids to control acid sludging problems during matrix treatments.