METHOD FOR OBTAINING A MODIFIED LIGNOSULFONATE REAGENT FOR THE TREATMENT OF DRILLING MUD Russian patent published in 2021 - IPC C09K8/35 B82Y99/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of drilling oil and gas wells, in particular to reagents for the chemical treatment of drilling muds in various mining and geological conditions. In the method for obtaining a modified lignosulfonate reagent for the treatment of drilling mud, iron (II) sulfate is introduced into the mass of a 50% aqueous solution of lignosulfonate, the reaction mass is kept for 1.0 hours at a temperature of 40±5°С. In the resulting mass for additional modification, phosphonic compounds are sequentially introduced in the form of a 25-30% aqueous solution: sodium triphosphate and nitrile-trimethyl phosphonic acid, the process of additional complexation continues for 1.0 hours at a temperature of 60±5°С, reagent consumption, wt.%: lignosulfonate 96.0; iron (II) sulfate 2.0; sodium triphosphate 1.0; nitrile-trimethyl phosphonic acid 1.0.

EFFECT: effective reduction in the indicators of relative viscosity and filtration, regulation of the structural and mechanical properties of drilling muds, resistance to mineral and temperature (up to 220°С) aggression and the absence of toxic chromium in the composition.

1 cl, 2 dwg, 4 tbl, 1 ex