ABSTRACT
Analysis of lignosulfonate drilling reagents showed that the reagents based on modified lignosulfonates, that is ferrochrome lignosulfonates (FCLS) are part of most drilling fluids. However, the content of toxic chromium (2.0-3.5% wt), high bottomhole temperatures (150-190°C), as well as a decrease in the volume and quality of sulfite lignosulfonate, which is the main source of raw materials, limits the possibility to use them. To obtain an effective drilling reagent capable of regulating the properties of the drilling fluid, the basic method for modifying the neutral sulfite lignosulfonate to produce drilling reagents with high qualitative characteristics has been improved - the liquefaction index is up to 60%, the filtration index is 6.0-6.5 cm3/30 min, the nominal viscosity is 24 s, and to increase the stability and resistance of the washing (drilling) liquid to temperature aggression, additional modifiers containing phosphonic compounds are introduced.
