Research on Drilling Technology of Inclined Strata in a Mining Area

During the drilling process, if the borehole is inclined, the obtained core data will be inaccurate, and in severe cases, it may even cause accidents inside the borehole. The factors causing borehole inclination mainly include geological (strata, rock properties, etc.) and engineering (equipment, technology) aspects. Starting from the construction parameters (rotation speed, pressure and flow rate) and equipment operation, by analyzing the interaction mechanism between the drill bit and the rock, the construction parameters that affect the borehole deviation are analyzed. Taking the construction of a certain mining area using a vertical shaft drilling rig and a crawler−type fully hydraulic drilling rig as an example, it is believed that when drilling in soft−hard interbedded layers and other inclined formations, using a rotation speed suitable for hard formations, appropriately controlling the drilling speed, and selecting the drilling parameters as follows: rotation speed 300−400 r/min, pressure 500−800 kg, flushing fluid flow rate 65−90 L/min, constant−speed drilling of the advance distance controlled at 15 cm/10 min, can effectively control the borehole deviation and simultaneously improve the construction efficiency.