METHOD FOR CHEMICAL CLEANING OF PIPELINES INTERNAL SURFACE Russian patent published in 2016 - IPC C23G3/04 C23G5/00 B08B9/53 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical cleaning of inner surface of the oil pipeline. Method involves preparation of a cleaned section of the pipeline and its chemical processing with an agent, which is performed by creation of at least two plugs of the chemical reagent, to form which, first, a piston is put inside the pipeline, then the second piston, and the space between the said pistons is filled with the chemical reagent, the third piston is put inside the pipeline, and the space between the second and the third pistons is filled with the chemical reagent, and by means of an inert gas the created plugs are moved inside the pipeline from the initial point of the cleaned section to the final point at the rate of not more than 1 km/h provided that the counter-pressure is created by the inert gas of at least 2 kg/cm². At least two cycles of the plugs movement are performed, then, at least 24 hours later and after inserting the two cleaning scrapers, at least two plugs of adsorptive light oil product are moved through the pipeline section with further removal of contaminated oil product, and after extraction of the last volume of the contaminated oil product the pipeline cleaning degree is checked.

EFFECT: invention provides efficient cleaning of a pipeline at meeting ecological requirements.

7 cl, 3 dwg