What problems do you usually encounter when operating a horizontal directional drilling rig

When the horizontal directional drilling opportunity has hole deflection and bending, the causes shall be analyzed and handled. Generally, the drill cone can be hoisted at the deflection to sweep the hole repeatedly to make the hole straight; When the deflection is severe, the clay shall be backfilled to the deflection, and the drilling shall be conducted after the sedimentation is dense. Paste drill and buried drill are often used in positive circulation (including submersible drill), internal reverse drilling and percussive drilling. In case of this, check and calculate according to the mud consistency, the inlet and outlet of drilling slag, the inner diameter of drill pipe, and the slag removal equipment, and control the appropriate footage; If the drilling has been severely pasted, the drilling shall be stopped and the drill cone shall be raised to remove the drilling slag. It is advisable to use fishing forks, hooks, rope sleeves and other things to quickly salvage the objects falling from the drill. If the falling body has been buried by sediment, the mud and sand shall be removed according to the above items, so that the salvaged objects can contact the falling body before salvage.
When the horizontal directional drilling opportunity has hole expansion and shrinkage, the method of avoiding hole collapse and excessive swing of drill cone shall be adopted. Shrinkage hole is caused by excessive wear of drill cone, untimely welding repair, or soft soil, clay and mudstone in the formation that expands when encountering water. For the former, pay attention to timely welding repair of drill cone, while for the latter, mud with low water loss rate shall be used for wall protection. When shrinkage cavity has occurred, it is advisable to use a drill cone to repeatedly sweep the hole up and down to expand the hole diameter. Stuck usually occurs in percussive drilling. After the drill is stuck, it is not advisable to lift it forcibly but gently. If it cannot be lifted gently, it can be impacted by a small impact drill cone or the drilling slag around the drill cone can be loosened by punching or sucking.
After hole collapse occurs, find out the cause and adopt corresponding measures, such as sticking to or increasing the water head, removing heavy objects, eliminating vibration, etc., to avoid continuous hole collapse, and then use a mud suction machine to suck out the soil that has collapsed into the hole. If the hole does not collapse continuously, normal grouting can be resumed. When the hole collapse is not serious, it can be backfilled above the hole collapse position, and the methods such as improving the mud performance, increasing the water head, and burying the pile casing can be adopted to continue drilling. In case of severe hole collapse, all the holes shall be backfilled with sand or small gravel mixed with clay immediately. After a period of suspension, find out the cause of hole collapse and adopt corresponding methods to re drill. When the hole collapse position is not deep, the method of deeply burying the pile casing can be adopted to tamp the soil around the pile casing and re drill. The hole collapse may be caused by water leakage around the bottom of the pile casing, water level in the hole drops or in tidal rivers, when the tide rises, the water level difference in the hole decreases, the original hydrostatic pressure cannot be maintained, and the hole collapse may be caused by heavy objects or machine vibration around the pile casing. In the process of grouting, if it is found that the mud level in the wellbore casing slurry rises suddenly and overflows the casing, then drops suddenly and bubbles emerge, it should be suspected that it is a hole collapse sign, and a sounding hammer can be used for exploration. If the sounding hammer was originally suspended on the concrete surface and was not taken out, it is now buried and cannot be lifted, or the sounding hammer cannot reach the original depth when exploring the concrete surface, with many differences, it can be proved that it is indeed a hole collapse.