Abstract: The present invention is a sequenced method of increasing the injectivity of oil bearing formations and increasing hydrocarbon recovery. The method of the invention is initiated by injecting an aqueous fluid at an ambient temperature into the formation through an injection well while concurrently recovering fluid at a production well. The first injection stage is followed by the injection of fluid of gradually increasing temperature until a temperature of about 75.degree.-100.degree. C. is reached. Finally, steam is injected into the formation.

Abstract: The magnitude of fluid drift rate at a well in a reservoir is determined by first injecting a known volume of a fluid containing a tracer, then shutting in the well for a period of time to allow movement of the injected tracer fluid, then producing said well while systematically analyzing produced fluid samples to determine the produced tracer concentration and therefrom the magnitude of the fluid drift rate in the reservoir.