METHOD FOR RECOVERING OIL FROM A RESERVOIR BY MEANS OF MICRO (NANO) - STRUCTURED FLUIDS WITH CONTROLLED RELEASE OF BARRIER SUBSTANCES

摘要

The present invention relates to a method for oil recovery from a reservoir which comprises the following phases : a) injecting a volume of a micro (nano) -structured fluid with released control of barrier substances into at least a portion of an underground reservoir containing oil, said micro (nano) -structured fluid comprising an aqueous dispersion of microcapsules composed of - a core comprising a modifying substance of the absolute permeability of the rock formation which houses said reservoir, - a protective shell insoluble in water which coats said core; b) clogging the porous intergranular spaces of said rock formation with said modifying substance with a reduction or inhibition of the absolute permeability of said rock formation, c) recovering said oil from the remaining portion of said reservoir by the further injection of a displacing fluid, preferably water. The present invention also relates to the above microcapsules and an aqueous dispersion comprising the above microcapsules for use in the above method.