Current Status and Prospects of Underground Drilling Equipment Technology in Coal Mines (Part 2)

 DTH drilling rig supplier introduces the main domestic drilling equipment according to the widely used classification method.

1.2.1 Split drilling rig

The split crawler rig with traditional crawler structure has always been the main type of drill rig in coal mines. Even in the situation where crawler rigs are commonly used, split rigs still occupy a large proportion, which is caused by the special restricted underground tunnel conditions. decided. According to the characteristics of underground drilling construction technology and the requirements of the basic performance parameters and structural form of the drilling rig, the split drilling rig is divided into three parts: the main machine, the console, and the pump station. The drilling rig generally adopts a valve-controlled hydraulic system and domestic hydraulic components. According to the needs of the hydraulic function circuit, it can realize shunting, merging, and special hydraulic linkage control to meet the requirements of various drilling conditions. The drilling rig generally has a wide speed and torque. The output range and the large feed/pull-out force, as well as the strong ability to deal with accidents in the hole, are typical of the durable, easy-to-maintain rig type.

1.2.2 Crawler mounted drilling rigs

With the rapid development of the "golden decade" of the coal industry, the mining speed and intensity of coal mines have increased significantly, and the contradiction between mining, digging and pumping has become increasingly prominent. Crawler-type full hydraulic drilling rigs have emerged at the historic moment, effectively solving the problem of the rapid movement of the drilling rig. At the same time, the reliability and drilling efficiency of the equipment is greatly improved. Xi'an Research Institute successfully developed ZDY6000L's first domestic underground self-propelled fully hydraulic crawler rig in 2005 and then began the development of serialized crawler hydraulic rigs. Based on the application of advanced hydraulic control technologies such as pump-controlled load sensing technology, constant pressure variable technology, constant power control, and proportional pilot control, the overall technical level of the drilling rig has been improved, which not only properly solves the problem of the difficulty of relocating the drilling rig in the tunnel, but also The control performance of the drilling rig is improved to achieve the purpose of convenience, accuracy, green energy saving.

According to the individual needs of users, in recent years, a variety of crawler rigs that solve the special needs of users and have strong pertinence have been developed and achieved good application results.

Crawler Mounted Drilling Rigs

1.2.3 Directional drilling rig

With the support of the National Development and Reform Commission, the Ministry of Science and Technology Industrialization Development Project and the National Science and Technology Major Project, the Xi’an Research Institute has taken the lead in conducting research on the directional drilling technology and equipment for measuring the kilometer while drilling in coal mines in 2005 and quickly obtained the technology breakthrough. The MWD directional drilling technology has changed the layout and construction mode of gas drainage boreholes, promoted the development of gas control technology in coal mines, and gradually expanded to be used in drilling projects such as underground water prevention and detection of hidden hazards.

1.2.4 Electro-hydraulic control automatic drilling rig

Underground coal mine intelligent drilling technology and equipment are advanced technical equipment that coal production enterprises urgently need. Chongqing Research Institute and Xi'an Research Institute have carried out relevant research based on national ministries and commissions and enterprise scientific research projects, and have achieved certain results, but many key technologies still need to be resolved The high-performance and high-reliability explosion-proof components available for selection are still very limited, and the level of intelligence and practicality need to be further improved.

The drilling rig adopts an integrated layout, which integrates the host, pump station, control console, remote control, explosion-proof control system, data acquisition, and detection system; through electro-hydraulic proportional control technology, with proximity switches, displacement sensors, pressure sensors and other components for signal The acquisition and transmission realize the joint control of the rig rotation, feed and extraction, clamping mechanism and the program-controlled automatic drilling construction. The wireless remote control is the main control method. On this basis, the hydraulic control console is retained to improve the safety and reliability of the operation. The developed automatic drilling control program can automatically adjust the drilling parameters and has the function of intelligent anti-stuck drilling. In automatic drilling, it takes 55 s for a single drill rod from adding rod to completion of drilling; for automatic unloading, it takes 50 s for a single drill rod. The drilling rig control system has fault intelligent diagnosis and early warning technology. It monitors the electro-hydraulic control system through a variety of sensors. The explosion-proof control cabinet can display various operating parameters of the drilling rig in real-time on a split-screen, and perform real-time monitoring, data communication, and fault diagnosis.

Aiming at a number of difficult problems of intelligent drilling in coal mines, scientific research is focused on, focusing on the development of intelligent drilling rigs with functions such as the intelligent perception of drilling conditions, intelligent control of the drilling process, autonomous navigation and positioning of drilling equipment, and multi-joint robots for automatic loading and unloading of drill pipes.

1.2.5 Self-propelled rubber rig

In 2015, Xi'an Research Institute conducted a research on the 10 million-ton modern large-scale mine trackless rubber wheel transport rig in Shanxi and Northern Shaanxi and developed the ZDY3500JD rubber wheel self-propelled rig, which adopts a dual-power drive mode. The explosion-proof diesel engine is driven by the rubber wheel chassis of the rig To provide power, the explosion-proof motor provides power for the drilling rig, and the cooling system adopts the air cooling mode, which is not limited by the on-site water source. The drilling rig is equipped with mud pulse wireless LWD measurement directional drilling technology, which can facilitate the construction of gas extraction at various angles within a depth of 300 m and the directional drilling of water drainage. The drilling rig can be moved to a remote location more quickly and efficiently. In 2018, in the field industrial test, the drilling rig carried out multiple long-distance and long-distance relocations in the underground, focusing on the driving performance of the rubber wheel chassis such as turning, braking, and climbing. The driving of the drilling rig is safe and stable, the braking is reliable, and the average With a travel speed of 15 km/h, only one person is required to complete the relocation task. The drilling rig is equipped with a Φ73 mm ordinary flat drill pipe and a wireless mud pulse measurement while drilling system. A total of 13 drill holes have been completed, including 4 conventional drill holes, a maximum hole depth of 198 m, a maximum inclination angle of 85°, and a maximum depression angle – 80°; 9 directional drilling holes with a maximum depth of 318 m, successfully penetrated the mined-out area and all hit the target area. The initial water inflow of the exploration and discharge hole of the construction was 93 m3/h, which effectively solved the problem of water hazards that plagued production.