What is the working principle and process of horizontal directional drilling?

1 Construction principle of horizontal directional drilling and pilot drilling Guided drilling is mainly completed by jet-assisted cutting bits. If the drill string is fed and rotated at the same time, the ramp loses its directionality and enables a straightened hole; if the drill string is only rotated, the reaction force acting on the ramp causes the bit to change direction. There is a probe or transmitter in the pilot bit.

2 Advantages and disadvantages of horizontal directional drilling Advantages: less interference to the surface, fast construction speed, controllable direction of pipeline laying, high construction precision. Disadvantages: The construction site requires a lot, it is difficult to construct in non-cohesive soil and gravel layer, and it is generally suitable for various soil layers without large pebbles.

3 Horizontal directional drilling construction process Construction preparation→measurement and setting out→equipment installation→drilling rig anchoring→mud preparation→pilot hole construction→hole reaming construction→pipe pullback.