To obtain the reserves above grade C, it is necessary to combine surface drilling and underground drilling to reach them. Underground drilling refers to the drilling work in which a special drill is used to drill a variety of different angles in a narrow underground tunnel. Compared with surface drilling, underground drilling is mostly an all-directional shallow hole with a small diameter. As we know, surface drilling is limited by the topography of the orebody and other conditions, often through a very thick overburden to control the orebody. However, the construction speed is slow and the cost is high to control the ore body by tunnel excavation. Therefore, underground drilling has been paid more and more attention.
Here is the content list:
Diesel units - the "power source" of drilling
What are horizontal and coal seam drills?
Do you know the deflection of underground drilling?
Diesel units are the power source for drilling, and each drilling rig is usually equipped with 3-5 high-powered diesel engines. They are the "power source" of the complete drilling rig and can lift the drilling tools (drilling tools consisting of square drill pipe, drill pipe, drill collar, and drill bit) weighing 200-300 tons so that the turntable drives the underground drilling to rotate rapidly to break the rock, and the drilling pump circulates the drilling fluid and forms a high-pressure fluid flow to flush the bottom of the well and carry out the rock chips from the drill pipe through the drill bit. rock chips.
In terms of drilling methods, underground drilling is usually adopted in addition to exploration drilling, and the drilling structure is relatively simple. Rotary drilling is a commonly used method. Only in hard rock without core and with high drilling speed, pneumatic impact underground drilling is used. Because the coal-bearing rock series is mostly soft and medium-hard rock, so cemented carbide underground drilling is most widely used. Diamond drilling is commonly used for coring or wire coring in hard rock. In recent years, the composite bit has also been applied in the underground coal mine. Some underground drillings also use the inserted tooth roller cone bit to drill large diameter coreless in the hard rock. In addition to applying proven techniques in surface drilling, horizontal drilling and coal drilling have been developed in underground drilling.
There are many kinds of manual deflection tools used in directional underground drilling, but stable assembly or screw underground drilling tools with deflection parts are better used in horizontal drilling and coal seam drilling. The advantages of directional underground drilling with a stable assembly (see stabilizer) are that deflection is performed while underground drilling normally, resulting in high ergonomics and low cost; The disadvantage is that the deflecting effect is largely dependent on the experience of the operator, and the control ability of borehole orientation (horizontal deviation) is poor. Using screw underground drilling tools with deflecting parts in directional underground drilling can improve the reliability of deflecting, and effectively control the inclination and azimuth Angle of drilling. However, the screw drilling tool price is high, the service life is short, increase the drilling cost, should only be used for a short time. In production, the two methods are usually combined to obtain better technical and economic results.
It is the responsibility of each manufacturer to produce underground drilling that meets the standards Hambition mining conducts many tests on underground drillings for connection before they leave the factory, and the quality qualification rate is guaranteed. If you are in the underground drilling business, you can consider our cost-effective products.