METHOD OF RECOVERING OIL FROM OIL-CONTAINING SLUDGES Russian patent published in 2001 - IPC

FIELD: alternative oil sources. SUBSTANCE: invention, in particular, relates to recovering oil from oil-bearing sandstones, oil-polluted soils, and heavy oil deposits by way of removing tar-asphaltene and paraffin deposits in production, transportation. Storage, and processing systems. Method consists in addition of organic solvent (in particular, petroleum distillates with boiling range 50-220 C) to sludge to achieve constant density of diluted sludge, which is further settled. When water and suspended particles are present in dissolved part of sludge, solution is additionally treated with aqueous solution of flocculant in proportion 10:1 (taking into account water contained if sludge), after which settled. Addition of solvent to sludge and treatment of sludge solution are advantageously carried out at stirring. EFFECT: increased degree of oil recovery. 3 cl, 1 dwg, 4 ex