Method of enhanced oil recovery from subterranean formations

摘要

A method of enhancing the amount of oil recovered from a subterranean oil-bearing formation by controlling the profile of the formation by introducing a predetermined first amount of a permeability control agent in a non-gelatinous state into the formation so that it contacts at least a portion of the formation. A portion of the pores of the formation are plugged by allowing contact to be maintained for a sufficient period of time allowing the first portion to gel. The first amount constitutes a portion of the total amount required to improve the profile of the formation. A predetermined second amount of permeability control agent is thereafter introduced, in a non-gelatinous state, into the formation which contacts the first amount and the portion of the formation not contacted by the first amount for a time period sufficient to gelatinize the second amount so as to plug the remaining unproductive pores of the formation. The second amount constitutes the remaining portion of the total amount required to improve the profile of the formation. Complete profile control is attained while not requiring any greater quantities of permeability control agent than those typically required in a single step profile control treatment.