Core flow tests evaluating HF acid systems designed to remove formation damage in sandstone formations, are traditionally conducted with undamaged cores which are often not taken from the actual formation of interest. However, HF acid treatments considered for field use should be evaluated in actual formation cores damaged prior to acidization, because sandstone acidizing success is dependent on both the formation sensitivities to HF acid and the effective removal of near-wellbore formation and perforation damage. Such damage may include drilling mud filtrate effects, plugging by fluid loss material, permeability reduction due to compaction and formation debris generated by perforating, and formation flow restriction caused by migratory or injected fines. This paper presents a systematic approach to core flow testing, in which procedures employed are designed to first, damage the cores in a manner representing expected damage mechanisms, then second, remove damage with appropriately selected HF treatment systems and non-acid pre-acidizing treatment systems, if necessary. The degree of damage removal and stimulation is measured following each treatment step. Acid systems are selected on the basis of formation characteristics, including min; eralogical make-up. The most cost-effective damage removal and acid treatment solution is then selected, based on comparative test results.