STABILIZATION OF THE FIELD WATER-OIL EMULSION BY ELECTROHYDRAULIC IMPACT WITH A 15-FOLD DECREASE IN VISCOSITY

Abstract

For the first time, the inverse, no less urgent, task of influencing the field oil-water emulsion (OWE) has been solved — not to destroy the OWE and decompose it into oil and water (a direct task), but to create a stable emulsion, while its viscosity should be significantlyreduced. The electrohydraulic effect was used to influence on OWE — the formation of a shock wave as a result of a pulsed plasma electrohydraulic discharge (PAED) in a liquid (electrohydraulic shock — E-shock). The study was carried out on crude water-oil emulsions of the Taylakovsky field of the Slavneft-Megionneftegas-Gazpromneft. The field OWE contains 80 % water and is located near the point of inversion «oil-water» to «water-oil», as a result of which its viscosity reaches critical values up to 50 Pa∙s, which does not allow it to be transported through pipelines without the use of expensive inhibitors. The effect of E-shock on the OWE led to multiple crushing of large liquid droplets and the formation of a stable, non-delaminating oil-water emulsion for a long time. At the same time, there was a decrease in the viscosity of the OWE by 15-20 times. As a result of the effect of E-shock on the OWE, the type of liquid has changed. From a non-Newtonian thixotropic fluid, the OWE was transformed into a Newtonian fluid with viscosity independent of the measurement time. It is shown that, in contrast to the generally accepted ideas, the viscosity of the OWE decreases, but does not increase with a decrease in the diameter of the droplets in the emulsion. The obtained practical results make it possible to transport OWE through pipelines without the use of expensive inhibitors and reduce the cost of its transportation by 2.5–5 times. We also studied the effect of E-shock on partially dehydrated up to 20% of the water content of the OWE of the Tailakovsky field. As a result of exposure, an emulsion stable for a period of more than 3 months with a decrease in viscosity by 2–3 times was obtained. The type of liquid of the oil-water emulsion has changed after the E-shock exposure — from a non-Newtonian liquid, the OWE becomes a Newtonian liquid.