USE OF INNOVATIVE SYSTEMS FOR EFFICIENT DRILLING OF WELLS IN THE QUARRY OF UKRAINE

for drilling hard rocks in the quarries of Ukraine.


Introduction.
One of the key processes in the quarries is drilling work. Effectiveness of their implementation depends primarily on the performance of the drilling equipment. Drilling machines must provide high performance, low cost, environmental requirements required diameter and depth of drilling have independent individual drive, high mobility and speed.
Analysis of the problem. Improving the efficiency of drilling and blasting operations in the quarries of Ukraine is the main direction that ensures a constant increase in the extraction of natural resources. Today, open pit mines use a wide range of drilling rigs and technologies to drill wells with diameters ranging from 40 to 350 mm in hard and very hard formations. The main technical and economic indicators of enterprises depend on the efficiency and productivity of drilling. The drilling process is also characterized by significant release of drill dust and explosion products, which have a large impact on environmental pollution and the health of workers.
The extremely high cost and low efficiency of drilling operations is a consequence of the use of outdated drilling rigs with low productivity and ineffective mining destructive tools in the Ukrainian open pits. The development of the latest explosive materials with high energy of destruction allows, during blasting operations, to reduce the diameter of drilled holes to 100 -150 mm. At the same time, these purposes require more productive, powerful and reliable drilling equipment, which provides high-speed drilling in hard rocks. In recent years, the productivity of drilling rigs has stabilized, but the mining and geological conditions of production have deteriorated significantly. The discrepancy between the parameters and modes of drilling leads to a constant increase in the costs of drilling in hard rocks, which reach 30-40% of the total cost of mining operations [3]. In the modern ecological aspect of protecting nature from mining, it is also important to control the release of large amounts of fine dust during drilling, which affects the health of personnel and environmental pollution. Therefore, the selection and implementation of productive drilling equipment with substantiation of the main parameters of well drilling to ensure high technical and economic indicators of mining, environmental protection and workers' health is an important theoretical and practical task of the mining industry.
The article is aimed at research and comparative assessment of the main technological and technical parameters of existing and newest innovative drilling equipment for a wide range of complex geological conditions in the quarries of Ukraine.
The main material. Table 1 shows the main characteristics of the operating drilling rigs SBS-250, SBU-125, Atlas Copco in the quarries of Ukraine. The main SBS drilling rigs are designed for drilling vertical wells with a diameter of dc = 160-350 mm and a depth of up to 35 m. The use of these machines with roller cone bits for crushing rocks with a strength factor f = 6-18 has low drilling speeds due to their technical imperfections. For example, the use of wells with a diameter of more than 200 mm in hard formations does not lead to a decrease in unit costs. In rocks with high resistance to fracture, the best performance is achieved when using wells with a diameter of 100-180 mm. The use of wells with a diameter of 215-250 mm under these conditions leads to an increase in explosive costs by 20-40% [4]. The main disadvantages of SBC machines are large mass and low resistance of bits in heavily drilled formations, high noise, vibration and dust emissions, accidents, maintenance complexity, low speed [5]. The development of new highly efficient drilling equipment has allowed to improve drilling equipment for drilling with diameters from 100 to 180 mm, which significantly increases productivity and reduces energy consumption of the process. All existing theories of mechanical destruction of rocks can be reduced to the energy theory, according to which the preferred method of destruction, modes and duration of the process, providing the minimum energy consumption for drilling [6]. Table 1. Technical specifications and parameters of drilling rigsт The principle drilling cutting method is based on the actions of large axial forces and torque on the drill [7]. Summed to slaughter borehole through the drill rod Nash power (W), which determines the performance of the method is calculated by the formula: where m0 -coefficient taking into account the type of bit and contact strength of rocks; D -diameter bits, m; nnumber of revolutions bit; G -axial force on a bit, N.
When percussion-drilling method, using submersible pneumatic drummer. Desktop Authority operates cyclic shock loading at low effort delivery and torque. Summed with the capacity to slaughter NY (Wt) is defined by the formula: where R -striker radius, m; Pc -the average pressure in the chamber of the forward striker, Pa; -first speed, m/s; -the ratio of the forward air-strike time to time reverse ( = 1.4 -1.6); A -energy single blow, J; -impact rate, Hz.
From formula (1) and (2) it follows that during drilling of one diameter drilling opportunities to increase productivity and increasing pressure determined first speed. This required axial force G (H) on the shock machine is determined by the expression: where η = 0.5 -0.7 -efficiency The principles of the axial force during cutting and air percussion different. When cutting drilling axial force is crucial for power on bottom hole. When air percussion axial clamping force pneumatic drummer to face no For the cutting method, we have: (5) and for air percussion: (6) Having real data in drilling wells with a diameter D = 0,215; m0 = 0,042; D = 0,215; nв= 1,33 c -1 ; Vy= 8 m/s; η = 0.5. get = Wш= 0.036 Wt /N and Wy = 2 Wt/ N.
It follows that the power that is removed from the unit axial force when cutting drilling of 40-50 times less than the percussion-way. This is one of the most important arguments advantages air percussion drilling method, especially for wells Use tools with an impact-rotary method of drilling with submersible pnevmoudarnykamy is one of the most promising and effective ways. With this method, the destruction of rocks made by impact shock loads at low axial pressures and speeds, and therefore such machines have a much higher performance and minimum energy drilling process [8]. Recently, drilling rigs of the Swedish engineering concern Atlas Copco, equipped with a pneumatic for down-the-hole hammer for rotary drilling, have been operated in the quarries of Ukraine. These rigs can drill holes with a diameter of 85 to 305 mm. with a drilling depth of up to 54 m, in rocks of medium and high strength. They are equipped with replaceable drill rods 5-7 m long with automatic installation during operation. The design of the base machine and drilling rigs allows drilling wells with angles of 0-90 degrees (Figure 1). They have high productivity and speed of drilling, mobility and speed, processing performance, low environmental impact, safe in operation [9]. Working equipment machine including compressor, mounted on a single platform. Having tracked and small size provide sufficient conditions for limited mobility and maneuverability. Equipment of diesel driven machine allows it to operate autonomously in small venues and working in an environment where there is no electricity supply system [10]. High-performance drilling rigs with pneumatic punches as provided by the drilling speed (the speed of penetration into the rock) and by minimizing the auxiliary and preparatory operations. Drilling machines "Atlas Copco" equipped with automatic extension rods, thanks to what the ratio of net drilling time to time for preparatory operations is 70/30. Efficiency drilling stalls "Atlas Copco provides powerful submersible pneumatic drummer or hydraulic hammer, designs and sizes which can drill holes with a diameter dc from 85 to 305 mm in rocks of medium strength to super-strong ( Table 2). The same drilling machine may use several sizes of pneumatic drummer COP. , The overall look and design submersible pneumatic drummer COP which is equipped with a drilling machine "Atlas Sopco" shown in Figure 2. Atlas Copko submersible rock drills use special heavy duty drill bits for crushing hard and abrasive formations ( fig. 3). They are equipped with ultra-hard, high-strength tungsten carbide and cobalt carbide spherical inserts for productive rock crushing and minimal displacement during high speed drilling [10,11].  To avoid excessive crushing of the rock in the well and the risk of jamming, waste is removed from the well at regular intervals (3-5 seconds) by blowing air in accordance with one of the three operating modes of the Copco air hammer (Fig. 4). When blowing the well according to the scheme (a, Fig. 4), the percussion mechanism of the pneumatic hammer stops as soon as the striker rises and falls together with the bit, therefore a large volume of air is blown through the striker and is well cleaned. According to the scheme (b, Fig. 5), the percussion mechanism is triggered and the striker is lowered to the bottom of the well, setting the bit to the percussion position and using a special purge valve (c, Fig. 4).
The use of an original well blowdown scheme and a vacuum cleaner above the wellhead allowed solving a very important task -to reduce emissions and dust concentration, as well as to reduce the man-made load on the environment and workers' health. Dust emissions Q from the drilling rig at a certain distance from the drilling site S for different types of machines (Fig.5). The proposed method for determining dust emissions when drilling blast holes with drilling rigs and methods for destroying rocks made it possible to determine the amount of dust released into the environment. Mass of dust released when drilling wells: where: Qopi is the volumetric power of the i-th drilling machine; dust extraction of dust from 1 m3 of drilled rock of the i-th car, kg / m3; Net operating time of the drilling machine per year, h / year; n -the total number of working machines in the quarry; K2 -coefficient that takes into account the humidity of the material. The value of Qopi can be obtained from the indicators of technical capacity: Mass of dust released when drilling wells per unit time: The maximum one-time emissions of hazardous products from drilling are shown in the table. 4: Table 4 -Results of calculating dust emissions during the operation of various drilling rigs The results of the research carried out on the productivity of drilling rigs in the quarries of Ukraine are presented in the graphs (Fig. 6). The dependences of the drilling speed Vb on the strength of rocks in the range f = 5-20 have been established. The research was carried out for quarries of Ukraine, where rocks and other minerals such as granite, marble, gabbro, labradorite, iron quartzite, diabase, diorite, travertine, sandstones, shales are developed and mined in difficult conditions. As can be seen from the graph (Fig. 6), with rock strength f = 10, the drilling speed of the ROC-L8 drilling rig with СOP DTH hammers is 2 times higher than that of SBU-125, and 6 times higher then SBC-250. When drilling wells with rock strength f = 14, the productivity of the ROC-L8 drilling rig is 3 times higher than that of the SBU-125, and 4 times higher than that of the SBC-250. With rock strength f = 18, the ROC-L8 rig has a 2-fold advantage in drilling speed over SBU-125, and 6 times over SBC-250. The productivity of ROC-L8 drilling rigs in the quarries of Ukraine in 2018 was 5600 m, which is 20% higher than that of the SBU-125 (4650 m). The productivity of the SBC-250 machine was 4200 m per month. Figure 7 shows the structure of discounted costs for drilling one running meter of a well for various drilling rigs.  Cost structure analysis shows that Atlas Copco's pneumatic submersible drilling rigs COP outperforms the SBC roller cutters primarily in terms of annual productivity [12]. This is due to the destruction of hard rocks with high-performance pneumatic hammers, an autonomous diesel drive, full automation of drilling support (replacement and extension of drill rods, replacement of bits, horizontal drilling), which reduces the drilling time and shortens the drilling time. transition from well to well. All Atlas Copco mechanisms are hydraulically driven, which provides good control and optimization of drilling parameters. But it should be borne in mind that while foreign cars are new, the cost of their repair is insignificant, but every year of operation it will grow.
Inefficient drilling rigs SBC-250 and SBU-125 are limited by their technical capabilities and energy efficiency, as well as by the conditions of use. Proceeding from the fact that drilling speed is an integral and comprehensive indicator of drilling operations in open pits, and especially the destruction of hard and heavy rocks, the use of Atlas Copco drilling machines with COP DTH hammers is the best option and a very promising direction of drilling equipment. The use of high-performance Atlas Copco machines, along with the development and implementation of modern explosives, makes it possible to reduce the drilling diameter, which will lead to a decrease in blasting operations, which significantly improves both the explosive and technical and economic indicators of mining enterprises in general.

Conclusions.
It is necessary to select drilling equipment on the basis of a technical and economic calculation of the conditions for achieving the minimum cost of the entire complex of processes: drilling, explosives, excavation, transportation, crushing, as well as the cost of explosives. The results of operation of Atlas Copco machines with COP DTH hammers have confirmed their effectiveness in drilling in a wide range of strengths in open pit mining [13]. COP down-the-hole hammers are more promising in use than SBC drilling rigs due to their increased productivity, efficiency, and drive motor power. High mobility and speed reduce technical waste of time. Atlas Copco drilling rigs provide high technical capabilities for high-precision drilling of wells with a diameter of 35 to 305 mm, a depth of 54 m in the range of 0 -90 degrees. The well blowdown system leads to high purity of cuttings, which qualitatively affects the efficiency of blasting operations. A reliable dust extraction system and a sealed cabin ensure the necessary hygienic standards during drilling, minimize vibration and noise impact on personnel and the environment. Reduces the emission of drill dust into the environment. The disadvantage is the high initial cost of drilling rigs and high requirements for the quality of the working fluid of the hydraulic drive.
Analysis of studies of the efficiency of Atlas Copco drilling machines in foreign and Ukrainian open pits shows their high productivity, efficiency and promising application.