A method of oil recovery by applying an electrical signal to a reservoir of interest, wherein said method comprises the following steps: obtaining the characteristic frequency of the water-oil interface of the reservoir; and applying the electrical signal to the reservoir, wherein said electrical signal is an alternating current signal or a combination of a direct current signal and an alternating current signal, and wherein the frequency of the alternating current signal is the characteristic frequency of the water-oil interface, thereby producing alteration of the water-oil interface and movement of the oil for extraction.