FIELD: oil and gas industry.
SUBSTANCE: invention relates to the refining methods for crude oil comprising mercaptans and sulfur-containing impurities, including crude oil contacting with a cleaning solution containing a hypochlorite solution for 30 s-2 min, during which the mercaptan sulfur is oxidized and converted into at least one sulfur oxo-acid or salt thereof, at output forming purified crude oil containing less than 50 ppm of mercaptan sulfur and residual chlorides. Purified crude oil containing residual chloride is brought into contact with a caustic solution with the mole ratio of caustic to chloride from 0.1:1 to 50:1 forming improved crude oil containing less than 50 ppm of chlorides. In one embodiment, the spent cleaning solution is recycled to form recovered hypochlorite flow to be used in the cleaning solution.
EFFECT: invention provides for mercaptan concentration reduction in crude oil.
14 cl, 1 dwg, 6 tbl, 21 ex
