Drilling rig

The drilling rigs

DRILLING RIG (EN: drill, borer, drilling rig; DE: Bohrgerat; FR: engin de forage, foreuse, sondeuse; ES: perforadora; RU: буровой станок) is the machine for the drilling of the blasting and mining-technical boreholes for various purposes, and also of the blastholes during the opencast and underground development of the useful minerals. The drilling rig is the major part of the multi-assembly drilling rigs, while the single-assembly drilling installations, which are used during the drilling of the geological-exploratory and other boreholes, are analogous to the drilling rigs according to the structure. Depending on the type of the rock-destructing tool, they distinguish the drilling rigs of the auger, roller-cone, pneumatic percussive, hydraulic percussive, and firing types. There are issued the drilling rigs with electric or diesel mover. According to the constructive realization of the turning-advancing mechanism, they distinguish the drilling rigs with the terminal, cartridge, and rotary turners. There are most distributed the first two schemes. The advancement of the drilling tool into the bottomhole is performed with the help of the hydraulic or pneumatic cylinders, of the rack with pinion system, or of the rope with polyspast system.

For the medium and heavy self-propelled rigs, all the working mechanisms and equipment are installed onto the platform. The self-propelled drilling rig includes the platform (frame) on the tracked, or pneumatic-machine chassis, or on the automobile, the mast, the turning-advancing mechanism with the drilling stand, the compressor, the oil station, various motors for the movers with the starting apparatuses, the monitoring-measuring and regulating devices for the process of the drilling, the systems for the pneumatic transport and dust capturing, the jacks for the installing of the rig. The light rigs obtain the compressed air from the stationary or movable compressors. Certain foreign drilling rigs for the open pit mines are equipped with the fire protection systems. The movable (portable) drilling rigs have the working tool with the mover, the strut columns for its installation within the underground mine working, the frame, onto which there are mounted all the parts of the rig, and the control panel.

The area for the usage of the drilling rigs is determined by the conditions of the development, by the strength of the rocks, and so on. In case of the underground mining works, and also in case of the road and hydraulic-technical construction, they use the light-weight (up to 1000 kilograms) movable (on the frame) or self-propelled drilling rigs. For the drilling of the boreholes with the diameter of up to 70 millimetres, they use the highly productive (100-300 metres per shift) drilling rigs with the powerful pneumatic and hydraulic hammer drills. Within the USSR, there have got the greatest distribution the rigs with the submersible pneumatic strikers, which they use mostly for the drilling of the boreholes with the diameter of 80-105 millimetres, for the ores, which are extracted by the underground method (more than 50%).

The roller-cone drilling rig for the open pit mines:The roller-cone drilling rig for the open pit mines

  1. the roller-cone drilling bit;
  2. the tracked chassis mechanism;
  3. the drill rods;
  4. the turner;
  5. the mast;
  6. the engine room;
  7. the hydraulic jacks.

They use at the open pit mines the roller-cone, firing, and auger drilling rigs, and also the pneumatic percussive rigs for the boreholes with the diameter of mainly 105-160 millimetres (see the "Pneumatic percussive drilling" article). They use the roller-cone drilling rigs (see the Figure # 2) for the drilling of the boreholes with the diameter of 160-400 millimetres within the rocks of the medium and high strength (f >= 6); they drill by these rigs more than 70% of the rock mass, which is extracted within the USSR (see the "Roller-cone drilling" article).

For the soft rocks (f < 6), they use the auger drilling rigs, during the drilling of the boreholes with the diameter of 125-160 millimetres (see the "Auger drilling" article). They drill approximately 2% of the rock mass (the quartz-containing rocks, f >= 14) by the firing drilling rigs (see the "Thermal drilling" article), by which it is more effective to expand the lower part of the borehole, which has been drilled by the roller-cone drilling rig, for the placement of the larger charge of the explosive substances within it. They use the cable-churn drilling rigs (see the "Cable-churn drilling" article) for the drilling of the water-lowering and other boreholes, with the diameter of up to 60 centimetres, and with the depth of up to 300 metres or more. For the achieving of the maximal possible performance of the drilling rigs, in compliance with the sanitary acceptable norms for the workers and for the equipment according to the vibration, there are developed and used the systems for the automatic control (ACS). For example, the ACS of the roller-cone rig, during the installation of the rig onto the axis of the future borehole, performs the automatic leveling of the rig, and then switches this rig into the mode for the drilling; simultaneously, depending on the strength of the rocks, there are automatically adjusted the optimal values for the axial force, and for the frequency of the rotation of the drilling tool. In case of the exceeding the maximal acceptable level of the vibrations, the block of the logic generates the signal for the decreasing of the axial force, and of the frequency of the rotation of the tool.

The prospect for the development of the drilling rigs is associated with the usage of the hydraulic percussive drilling machines, of the systems for the automatic control, of the hydraulic mover for the assemblies, with the creation of the rigs-robots.