On the example of geological conditions of the central part of Western Siberia the characteristics of polymer-clay compositions based on the domestic reagent "Kometa-Meteor" and the possibilities of its application for drilling wells are considered. The reagent "Kometa-Meteor" is proposed as a hydration inhibitor in drilling mud. The results of studies have shown that the use of this reagent effectively prevents complications associated with wellbore instability during drilling. A comparative analysis of various compositions based on the polymer "Kometa-Meteor" and other widely used drilling fluid systems has been carried out.