The OneSTEP system saved PDVSA two days of operation time on average in each of three wells, minimized the risk of deferred production, and reduced the mud acid treatment volume by 57% in comparison with conventional systems for sandstone acidizing. Cumulative oil production increased by 95%—from 1,241 bbl/d to 2,415 bbl/d— in the three wells treated using the OneSTEP system. In one of the three wells, the OneSTEP system was used with a single chelant agent stimulation fluid to treat a 72-ft zone, making diversion easier and more practical than injecting a sequence of fluids with relative volumes.