دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: 1. an injection of water prior to chemical flooding that is used to induce reservoir conditions favorable to the surfactant solution by adjusting reservoir salinity and reducing ion concentrations. A preflush may also be used to obtain advance information on reservoir flow patterns. 2. fluid injected prior to the acid solution pumped into a well in an acid-stimulation treatment;sometimes called a spearhead. Compare overflush.