Scientific and technological foundations of groundwater deposits development with forced self-discharge

Introduction. A two-well borehole system is proposed, providing for the extraction of groundwater by forced self-discharge. The essence is to create conditions for the emergence of a down hole energy source in the form of hydraulic shocks, alternating hydraulic impulses affecting aquifers and ensuring the rise of water to a height. Materials and methods of research. A block diagram of a two-well circulation system of wells consisting of an above-ground tank, an injection well with a ledge, a water-lifting well connected by an intermediate trunk. The objects of the study are the shape of the above–ground tank, its connection with the injection well, the location of the ledge and the conditions for conducting a water circulation channel from the ledge to the above-ground tank. Methods – calculation of the energy characteristics of a two-well system, experiments to study the mechanism of the origin of incomplete hydraulic shock, boundary values of the modes of water movement in the system and the coefficient of injection of rocks. They were carried out on the installation with the possibility of visual observation of the processes taking place in the system. Results. When an incomplete hydraulic shock occurs on the ledge of the injection well, the flow is divided into core and lateral components. The water flow from the tank into the well was in the range of 20–60 l/min. The origin of incomplete hydraulic shock occurred at a water flow rate of 20 l/min, with an increase in pressure up to 7.0 atmospheres. The boundary values of the laminar flow mode of water flow are 60 l/min. The height of the water rise (H) mainly depends on the depth of origin of incomplete hydraulic shock (H1). The ejection coefficient of rocks decreases with increasing flow rate of the working flow. Discussion. The results of the study are due to the design features of the elements of the two-well circulation system of wells. The operating conditions of the system are the type of communication ground tank – injection well – aquifer, the location of the ledge, the execution of the water circulation channel from the ledge to the entrance to the ground tank with one diameter, the preservation of the laminar flow regime of water, the exclusion of pressure loss and water leakage in the intermediate trunk. Conclusions. The conditions for the origin of a down hole energy source in the form of renewable hydraulic shocks, which have a hydro impulsive effect on aquifers, have been established. A block diagram of the injection and circulation system of wells for the extraction of groundwater by forced self-discharge has been formed. Resume. The validity of the idea of injection-forced self-discharge of groundwater is proved by the results of research. The results are applicable in the development of groundwater with low-pressure and non-pressure aquifers. The objects of future research are the optimal ratios of the diameter of the injection well and the passage section of the ledge, the expansion of the boundary values of the flow transition from laminar to turbulent motion, and an increase in the ejection coefficient.