دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a method of improved oil recovery in which chemicals dissolved in water are pumped into a reservoir through injection wells to mobilise oil left behind after primary or secondary recovery and to move it toward production wells. The chemical solution includes surfactants or surfactant-forming chemicals that reduce the interfacial and capillary forces between oil and water. releasing the oil and carrying it out of the pores where it has been trapped. The solution may also contain cosurfactants to match the viscosity of the solution to that of the oil to stabilise the solution and to prevent its adsorption by reservoir rock. An electrolyte is often added to aid in adjusting viscosity. Injection of the chemical solution is followed by a slug of water thickened with a polymer. which pushes the released oil through the reservoir. decreases the effective permeability of established channels so that new channels are opened. and serves as a mobility buffer between the chemical solution and the final injection of water.