ASPECT OF INTRASTRATAL COMBUSTION FOR ENHANCEMENT OF OIL RECOVERY

Abstract

Intrastratal combustion is a heat treatment of petroliferous strats in order to enhance the oil recovery from them. The heat is produced in the pay stratum itself, by combustion of some of its oil. An oxidizing agent (usually air, sometimes with added oxygen) is pumped into the stratum for the purpose. The most widely used form of this treatment is wet in-situ combustion, in which a certain amount of water is injected together with the air. In the zone of vigorous oxidation where the temperature may be 500° or higher, the water evaporates, producing steam that efficiently displaces the oil out of the rock. In laboratory investigations of this process, the authors analyzed the changes in the trace elements of the fluids expelled from a simulated pay stratum. It was found that the trace metals of the vanadium-porphyrin complex migrated from the oil into the water.