What is the construction process for a horizontal directional drilling rig?

1. Preliminary Preparation: Complete surveying and setting out, determine the locations of the entry and exit points, arrange the drilling site, and complete equipment installation and commissioning. Simultaneously, calibrate the directional control parameters and prepare drilling mud suitable for the geological formation.

2. Drilling the Pilot Hole: Following the pre-designed trajectory, use a drill bit with a guide device to drill from the entry point. By monitoring the drill bit's underground 3D coordinates in real time, precisely control the drilling path, and finally drill to the surface at the designated location.

3. Staged Pre-reaming: After the pilot hole is completed, according to the size of the pipeline to be laid, replace the reamer with different specifications and gradually enlarge the hole diameter from the exit point back, ensuring that the final hole diameter is 1.3 to 1.5 times larger than the pipeline diameter. Simultaneously, use drilling mud to remove drill cuttings and prevent borehole collapse.

4. Pipeline Retraction: The prefabricated pipeline to be laid is connected to the rear of the borehole reamer using a swivel joint. The drilling rig is then pulled back at a constant speed from one side of the entry point, dragging the pipeline along the reamed hole into the ground until it is fully in place.

5. Final Finishing: After the pipeline retraction is completed, borehole continuity testing, external grouting reinforcement, and other operations are performed. Finally, the construction site is cleaned up, and the ground is restored to its original condition.