1. pre-drilling preparation

1. Chamber excavation: excavate chamber and pour chamber floor according to the inclination angle of the well and the type of drilling rig. The floor of the chamber shall be flat. When pouring the floor, anchor bolt installation holes (secondary pouring) shall be reserved for the installation of the drilling machine. In order to discharge the rock slag discharged when the pilot hole is drilled, a 300 × 300mm (long) drainage ditch shall be poured when pouring the foundation. The ditch shall have a certain slope to facilitate slag discharge. If there is no ditch in the roadway, a water nest must be dug to install a submersible pump.

2. Slagging method: determine the pressure and flow rate of flushing fluid according to the well depth. Generally, clear water is used to discharge slag in underground coal mines, and the water pressure is about 2Mpa. If the water pressure is small, a hydraulic pump can be installed to ensure sufficient water pressure to discharge the rock slag when the pilot hole is drilled.

Stable installation of 2. drilling rig

1. Before drilling, the anti-well drilling rig must first be fixed on the foundation. After the drilling rig is leveled, the upper support is supported to the roadway roof with an extension rod to prevent the fuselage from shaking during drilling.

2. Technical Requirements and Precautions: After the drilling site is selected, the construction shall be carried out according to the foundation drawing of the main engine. The foundation must be horizontal, especially the upper plane level of the secondary watering reserved on the foundation pit is particularly important, and it must have sufficient strength. The main frame shall be watered in the foundation with 8 anchor bolts for secondary watering. The connection between the bolt and the foundation plate of the drilling machine must be firm, the thickness of the foundation concrete shall not be less than 300mm, and the strength shall not be less than the standard strength of 200. For the soft surrounding rock of the bottom plate, the area and thickness of the foundation should be increased, and the thickness of concrete can be increased to more than 700mm. The bottom plate of N 1317 gangue bin is tuff, which is easy to soften when exposed to water. The thickness of concrete is 700mm. The foundation is deformed during drilling.

Deviation control of 3. drilling rig

1. Deflection of drilling rig. In drilling engineering, due to various reasons, the center line of the drilled hole intersects with the main axis of the drilling rig or the main machine is offset, so that the drilling rig will deviate. If the deviation rate (the slope between the center line of the drilling pilot hole and the main axis of the drilling rig) exceeds the allowable value during drilling, the deviation will occur. The working state of the anti-drilling rig is different under normal conditions and under deviation conditions. When the normal drilling speed is reached after deflection, the required push-pull force and torque force are greatly increased, and the vibration is intensified. Deflection of the drilling rig has an obvious feature. When replacing the drill pipe, the lower slip will not go in and the drill pipe cannot be replaced. Deflection of the drilling rig will cause the drilling to fail to reach the intended location, resulting in offset holes.

2, control bias technology. According to practical experience, the implementation of the following measures can effectively prevent drilling deflection rate:(1) take correct and effective stable installation. (2) Use short drill pipe, low axial pressure and slow drilling speed to open the hole until the first stable drill pipe enters the guide hole, increase the axial pressure as appropriate to increase the drilling speed. After the drilling depth exceeds 3m, press again to drill according to the normal parameters. (3) The drill pipe of the drilling machine must be tightened with the connecting wire of the drill bit. (4) guide hole use guide. (5) Add 1 stabilizer for every 10m drilled during drilling. (6) Pay close attention to the change of the rock formation during the drilling process, and drill in the heterogeneous rock formation due to low speed drilling. (7) Check frequently during drilling, and tighten loose stable components in time. If overdeflection occurs, it must be adjusted in time.

IV. Anti-blocking of Guide Hole

1. Reasons for anti-blocking: The slag discharge capacity of the selected slag discharge method is insufficient, and insufficient water pressure and flow are the main reasons.

2. Solution: The drilling speed should match the slag discharge capacity, and the slag discharge capacity should be greater than the cuttings generated by drilling.

V. Replacement of Drill Pipe

1. The process of replacing drill pipes requires high requirements for drilling rig operators and drill pipe replacement operators, who are required to be cautious and cooperate with each other with great skill and tacit understanding. The following difficulties often occur in the process of replacing drill pipes:(1) drill pipes cannot be unloaded,(2) kava cannot be inserted.

2. Solution (1) The drill pipe cannot be unloaded: when loading the drill pipe, a steel ring made of steel bars with a diameter of 6mm is added between the drill pipes. (2) The lower slip goes in: if the lower slip does not go in, it means that the machine body of the drilling rig is not straight, and the machine body needs to be leveled again.

VI. Precautions

For reaming, 1MPa pressure water should be used to cool the cutter plate and cutter to avoid sparks when the cutter is cutting rocks, and the measures of boiling water first, starting drilling later, stopping drilling first and closing water later shall be implemented. In case of hydraulic oil leakage during installation, commissioning and maintenance, the drilling rig shall be stopped immediately, and the leakage shall be handled in time. When the drilling depth exceeds 20m, the machine shall be shut down for 2min to discharge slag after each drill pipe is drilled.