Determination of method controlling of rod drives open-pit drilling rig

Abstract

Purpose. Rational method determination for controlling automated drive systems for rotation and feeding of explosive wells drilling rig. The methods. The study is based on the analysis of the energy balance in the bottomhole zone. To increase the stability of the roller cutter bit by controlling the energy flow in the bottomhole zone, a method of controlling the drilling process with the control of the feed and rotation mechanisms drives was developed, which forms hard mechanical characteristics on the roller cutter bit when penetrating rocks with low strength and soft mechanical characteristics in more durable rocks. Findings. The control methods for maintaining one of the following parameters at a constant level are analyzed: bit rotation frequency, bit resistance torque, bit linear speed, axial pressure on the bit, and power consumed by the rotation drive. Based on the energy criterion of bit stability, a rational method for controlling the rotary bit drive of a core drilling rig was developed. It has been established that the bit will have the greatest stability when its energy load is uniform, i.e., when the rock fracture energy is maintained at a linear increase or when the power generated in the contact zone of the bit with the bottom hole is maintained at a constant level. The originality. t has been established that the bit has the greatest stability under a uniform energy load, i.e., when maintaining a linear increase in the energy of rock destruction or when maintaining a constant level of power released in the bit- face contact zone. The established bit efficiency criterion summarizes the previously proposed criteria (penetration per bit, bit motor life, conditional bit wear), as it automatically considers the strength and abrasiveness of the rock being destroyed by the bit. Practical implementation. The proposed method of controlling the drives for feeding and rotating the drilling rod in the process of drilling ensures uniform energy loading of the core bit by forming hard mechanical characteristics on the core bit when penetrating rocks with a strength in the range of 10-13 units according to the scale of Prof. M.M. Protodyakonov and soft mechanical characteristics in stronger rocks. When drilling intermixed rocks with different physical and mechanical properties, the control method provides automatic selection of mechanical characteristics depending on the rock strength.