METHOD FOR WASHING OIL-CONTAMINATED SOILS Russian patent published in 2021 - IPC B09C1/02 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: method can be used in flushing soils contaminated with oil products during normal operation of oil refining, petrochemical and oil producing enterprises, oil storage tanks and oil storages. Essence of invention consists in the fact that soil is washed with aqueous solution of surfactants using pressure and production wells, before injection into formation solution of surfactants is subjected to treatment with spark pulse high-voltage discharges with formation in solution of ozone and hydrogen peroxide, as well as pulsed hydraulic shocks, which are propagated in the formation with pumped solution, the solution is filtered in the formation in the electric field alternately in the direction of the electric field intensity vector and in the opposite direction, wherein electric field is directed perpendicularly to water flow, and nearby water flow is intercepted technogenic flow of ground water, which together with washing solution is directed to separation of flow into suspended substances, oil products and water. Oil products are dehydrated and utilized, and water is additionally filtered in coalescing charge, floated, then surfactant concentration is corrected, heated and pumped again into formation. Injection and production wells are arranged in alternating rows. 100 % solution is injected into the first row of injection wells, and in remaining injection wells - 20 % solution. 100 % solution is extracted from the last row of production wells, and 20 % of the solution is extracted from the remaining rows of production wells.

EFFECT: high efficiency of extracting petroleum products from technologically contaminated soils, high quality of reclaimed soils.

1 cl, 1 dwg, 2 tbl