METHOD OF PRODUCING MODIFIED FERROCHROME-LIGNOSULPHONATE REAGENT Russian patent published in 2017 - IPC C09K8/35 

FIELD: oil industry.

SUBSTANCE: invention relates to drilling oil and gas wells, in particular to reagents for chemical treatment of drilling mud. Method of producing modified ferrochrome-lignosulphonate reagent involves creation in a reaction mass of lignosulphonate a redox system of Fe⁺² and Cr⁶⁺ and production of chromium and iron in trivalent form to form complexes with lignosulphonate and drying. Disclosed method includes adding to liquid technical lignosulphonate (II) sulphate, holding mass with mixing for 1.0 hour at temperature 30–40 °C. Sodium bichromate is introduced into produced mass in form of an aqueous solution, held with constant mixing for 1.0 hour at temperature 30–40 °C. Method then includes adding a modifying agent – sodium triphosphate chelating agent in form of aqueous solution. Mass is held with constant mixing for 1.0 hour at temperature 30–40 °C, acidified with sulphuric acid in form of an aqueous solution in an amount to pH 4.0–5.0, after which mass is dried in a spray dryer.

EFFECT: technical result is obtaining a ferrochrome-lignosulphonate reagent, which enables to obtain complex compounds with high diluting effect and heat resistance, as well as reduced content of toxic chromium in reagent.

1 cl, 2 dwg, 3 tbl, 1 ex