A method for enhancing steam drive recovery of oil from an oil zone disposed below an overburden (18) including injecting a surfactant continuously into a supply (20) of driving steam to uniformly mix the surfactant with the steam and thereby provide a driving fluid. The driving fluid is then introduced...http://www.google.de/patents/US4516636?utm_source=gb-gplus-sharePatent US4516636 - Enhanced steam drive recovery of heavy oil
