Reduction of sticking risk in well-boring through reagent treatment of drilling fluid

Drilling fluids for deep and extended reach wells are complex multicomponent systems that contain dissolved salts, polymers, surfactants and coarse solids. Complexity of drilling mud is caused by wide range of functions: creating pressure on the formation, retention of cuttings particles in suspension, bottom- hole cleaning and transportation of sludge on the surface, preservation of reservoir properties of the target formation and other. Tribological properties are one of the most important properties of the drilling fluids. It is possible to control properties through introduction of lubricant additives. Their components are characterized by high, sometimes unique, surface activity, they create superplastic nanofilms on the surface of the protective pipe, contribute to chemical modification of the surface layers of metal. The choice of such components is complicated, first of all, by price (to construct wells one needs large volumes of mud), and secondly by strict environmental requirements. Therefore, when lubricant additive is developed, it is necessary to ground the choice of rational content for each of its components. This necessitates the use of mathematical modeling methods, i.e. construction of regression equations according to several experiments of the planned experiment. The paper presents a possible way to use the two-step method of choosing the rational ratio of the components in the lubricant additive. As a rule tribological properties of drilling fluids are considered from three different points of view or different positions - friction pairs: «metal - rock», «metal - metal» and «metal - filter cake». This article is devoted to the study of drilling fluids in relation to a pair of «metal - filter cake».