Purpose. To analyse certain complex components of the rock breaking act during the well construction stipulated by the design features of the technical means of hydromechanical drilling and diversity of manifestations of hydraulic and physicochemical properties of the activated circulation medium. Methodology. Physicochemical parameters of the process of active substance adsorption from the water solutions on the rock surfaces were studied in terms of their disperse material by identifying optimal ratio in the solid phase particles volume of the activated solution group with the recording of time interval of the adsorption equilibrium establishment. Features of bottomhole processes in terms of the operating modernized facilities of hydromechanical drilling were considered involving up-to-date methods of analytical analysis and experimental-laboratory studies, i.e. by using certain techniques of mathematical and physical modelling, methods for processing and interpretation of the research results by means of SolidWorks, STATGRAPHICS, D, and control-and-measuring equipment and materials. Findings. The peculiarities of the combined hydromechanical drilling technique have been analysed from the viewpoint of the creation of the most efficient conditions of bottomhole rock breaking. Since a considerable degree of the development of breaking processes is the practically proved factor of hydromechanical drilling, the rationalization and intensification of those processes may be achieved by means of controlled physicochemical effect of the surface active medium. The experimental study was carried out to analyse the directedness of the development and results of surface interaction adsorption within the boundary of phase separation as the main factor of intensification of the rock mass breaking. A comparative analysis was performed concerning the surface activity of the corresponding substances that differ in their schemes of dissociation in a water solution whose properties are to be corrected additionally to make them close to the ones peculiar for natural drill muds. Positive influence of the adsorption phenomenon on the results of contact interaction of breaking elements of hydromechanical facilities was examined; this phenomenon is shown in the decelerated wear of metal surfaces. Originality. Useful influence of the physicochemical properties of the substances under consideration decreases beginning from the ionogenic anion-active sulfonol towards the ionogenic cation-active katapin K and to the non-ionogenic substance OP-10 (-10). However, in terms of combining the compositions of the mentioned substances, it can be strengthened additionally. Practical value. The indicated laboratory and experimental studies are the basic ones to design the mode parameters of the washing programme for a hydromechanical drilling well; they belong to the main output data used while substantiating the design and technical-technological parameters of the modernized pellet impact devices.

В роботі показана суттєвість ролі вибійних руйнівних процесів з огляду на необхідність скорочення витрат на буровий інструмент. Доведено, що за певних геолого-технічних умов, застосування бурового інструменту, озброєного твердосплавним матеріалом є доцільним. Розглянуто деякі важливі фізико-механічні характеристики твердих сплавів, корегування яких дозволить розширити діапазон використання відповідного породоруйнівного інструменту та систем його техніко-технологічного супроводження. Висвітлено конструктивні принципи та переваги запропонованих схем виконання пристроїв для буріння свердловин, що базуються на максимальному використанні особливостей стану деформованого впливом куль вибою.

Purpose. To rationalize well washing by considering the influence of the annular channel limitation, granulometric composition of the mud, limitation of the joint movement of mud particles, drill string rotation, shape of the movement channel, and rheological properties of a cleaning agent. Methodology. Applied laboratory studies on the properties of drilling fluids are carried out using modern methods of analytical analysis and experimental studies, in particular, by using general principles of mathematical and physical modelling, methods of processing the results of studies in the EXCEL, MATNSAD environment, control and measuring devices of the laboratory of washing liquids of the Department of Oil-and-Gas Engineering and Drilling of Dnipro University of Technology (hydrometer, viscometer, plastometer, stalagmometer), and materials (technical water, clay bentonite powder, reagents, stabilizers and activators, surfactants as well as equipment and laboratory base of “Ukrnafta” PJSC to carry out certain stages of research. Findings. The properties of surface-active substances and activated washing liquids are analyzed. The main technological properties of drilling fluids are studied. Comprehensive information on the physical and chemical ability of flushing drilling fluids is provided. The main technological measures ensuring the stability of drilling process using activated-surfactant drilling fluids are considered in detail. The main technological principles of determining rational formulations of a selected cleaning agent in the circulation of Newtonian liquids are formulated and substantiated. A detailed description of surfactants, their properties and methods to study the formed solutions is given. Originality. The process of a rock-breaking tool on the well bottom will be stable in the conditions of dynamic equilibrium of the rock-breaking processes and removal of broken products into the annular space. Therefore, for a correct understanding of wellbore washing issues, basic regularities are established of the specified processes and the influence of various factors on these processes. Practical value. It has been proven that in order to give a drilling fluid the necessary properties that, on the one hand, will ensure an increase in the efficiency of rock breaking on the well bottom, and, on the other hand, will create favourable conditions for stable removal of cuttings onto the surface and maintenance of the well walls in a stable condition, it is necessary to apply different methods, in particular chemical activation as well as magnetic, thermal and electrochemical activation, in its different varieties.