ASPHALT-TAR-PARAFFIN DEPOSIT REMOVING COMPOSITION (VARIANTS) Russian patent published in 2006 - IPC E21B37/06 

FIELD: oil production, particularly compositions for asphalt-tar-paraffin deposits removing in bottomhole formation zone, from oil production equipment surfaces, from reservoirs and oil accumulation tanks and from pipelines.

SUBSTANCE: composition comprises solvent taken in amount of 67.0-98.9% by weight, polar nonelectrolyte, namely butyl alcohol still residues taken in amount of 1-30% by weight, surfactant taken in amount of 0.1-3.0% by weight. In accordance with the first embodiment the solvent is liquid pyrolysis product or 30-180°C hydrocarbon fraction obtained by above liquid pyrolysis product rectification or mixture thereof in arbitrary combination of above substances in the mixture. In accordance with the second embodiment the solvent is 145-180°C hydrocarbon fraction, obtained by liquid pyrolysis product rectification or absorbent rectification or mixture including liquid pyrolysis products and absorbent, wherein above hydrocarbon fractions may be used separately or compose mixture to which 2-7% of vinylbenzene is added. In accordance with the third embodiment the solvent is liquid pyrolysis product and/or 30-180°C hydrocarbon fraction, obtained by liquid pyrolysis product rectification and 145-180°C hydrocarbon fraction, obtained by liquid pyrolysis product or absorbent rectification or mixture including liquid pyrolysis product and absorbent taken in arbitrary amounts and vinylbenzene added in amount of 2-7%.

EFFECT: increased tar-paraffin deposit dissolving ability at high temperatures, widened raw material source, possibility to use petrochemical waste products.

3 cl, 3 tbl