INCREASING OIL RECOVERY APPLYING ELECTRIC STIMULATION ON THE FORMATION

The work is devoted to increasing the degree of depletion of reserves of longterm exploited hydrocarbon deposits on the basis of the obtained results of theoretical and experimental studies of the application of electrodynamic technologies for stimulating the formation and bottomhole formation zone. The electrolysis of formation fluids, water, oil-bearing rocks, is accompanied by a mass transfer, primary and secondary chemical reactions, the formation of all kinds of salts, alkalis and acids, new organic substances and all kinds of surfactants. Not only the liquid is subjected to electrolysis, but also the oil and gas bearing rocks themselves (solid electrolyte). The magnetic and electrical forces arising during the electric treatment of reservoirs make it possible to effectively drain heterogeneous reservoirs and extract residual oil from non-working layers. The work also carried out experiments to study the effect of the electric field on the surface tension coefficient at the oil-water interface. The circumstance of an abrupt change in the surface tension coefficient at the oil-water interface makes it possible in principle to create conditions in the reservoir that make it possible to slow down the cusping processes by applying an electric field of various magnitudes or, in other words, by regulating the amount of mass transfer. In numerical terms, the oil recovery factor without electrophysical treatment was 52.94%. Under electrophysical impact, the oil recovery factor was 94.12%, i.e. equaled to almost complete extraction of oil from the sample. In the field, this figure, of course, will decrease by 2-3 times, but it remains quite high in comparison with other methods of increasing oil recovery. Thus, the studies performed on samples in laboratory conditions indicate the possibility of using constant electric fields to increase oil recovery from depleted watered formations. Electrochemical treatment of the formation can significantly increase the displacement of oil from the formation. The increase in oil displacement reaches 15-20% and more. With the help of water alone, 58% of the oil (of its total volume in the sand) was displaced from the sand, and under electric field with a voltage of 10 V and 20 V, the total amount of displaced oil, respectively, increased to 67 and 83%. Thus, the laboratory studies performed on the samples also indicate the possibility of using constant electric fields to increase oil recovery from depleted watered formations. The carried out theoretical and experimental studies show the possibility of using the technology of electrochemical and electrothermochemical leaching of oilsaturated rocks to intensify oil production. The effectiveness of the recommended technology is especially noticeable in fields that have entered the final stage of development with a high water cut.