Abstract: A method of treatment of a subterranean hydrocarbon-bearing reservoir, the reservoir comprising at least one porous and permeable rock formation, the reservoir being penetrated by a plurality of injection wells and one or more production wells, the injection wells sharing a common injection header for delivering an aqueous injection fluid to the injection wells, the method comprising: a. identifying a group of injection wells selected from the injection wells sharing the common injection header; b. determining a cumulative volume of the treatment stream that is to be supplied contemporaneously to all of the injection wells within the identified group; c. simultaneously transmitting the treatment stream only to the identified group of injection wells so as to inject the treatment stream into the reservoir, thereby treating the reservoir to improve the sweep efficiency of subsequently injected fluid.