METHOD OF PRODUCING INHIBITED HYDROCHLORIC ACID Russian patent published in 2020 - IPC C23F11/04 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing inhibited hydrochloric acid used in oil production, namely to production of inhibited hydrochloric acid used for treatment of bottom-hole zones of oil and water-injection wells. Method of producing inhibited hydrochloric acid involves diluting it to the required concentration and introducing a calculated amount of the inhibitory mixture which contains a nitrogen-containing compound which is primary aliphatic amines of formula NH₂R, where R is alkyl with number of hydrocarbon atoms C₁₀-C₁₄, non-ionic surfactant and formaldehyde-containing compound. Prior to introduction into hydrochloric acid, said components are mixed in the following order: initially the formaldehyde-containing compound is mixed with a portion of hydrochloric acid in weight ratio of 15–20:1, then successively introducing primary aliphatic amines, non-ionic surfactant and additionally after loading of all components, polyethylene polyamines taken in weight ratio to primary aliphatic amines 1:2–5 are introduced. Obtained mixture is used to inhibit hydrochloric acid with concentration of 20–29 % in weight ratio 0.005–0.01:1.

EFFECT: technical result is obtaining more concentrated inhibited hydrochloric acid with improved inhibiting properties.

1 cl, 2 tbl, 12 ex