What is the working principle and technology of horizontal directional drilling

Working principle of horizontal directional drilling:
1 Construction principle of horizontal directional drilling and directional drilling
The pilot drilling is mainly completed by jet assisted cutting bit. If the drill string is fed and rotated at the same time, the inclined plane will lose its directivity and straighten the hole; If only the drill string is rotated, the reaction force acting on the slope causes the drill bit to change direction. There is a probe or transmitter in the pilot bit.
2 Advantages and disadvantages of horizontal directional drilling
Advantages: small interference to the surface, fast construction speed, controllable pipeline laying direction and high construction accuracy. Disadvantages: The construction site has a large requirement, so it is difficult to construct in non cohesive soil and gravel layer, and it is usually applicable to various soil layers without boulders.
3 Construction process of horizontal directional drilling
Construction preparation → surveying and setting out → equipment installation → drilling rig anchoring → mud preparation → pilot hole construction → reaming construction → pipe dragging back.
Horizontal directional drilling is flooded, how to deal with it?
1、 Engine water ingress
1. Drain all the oil-water mixture from the oil pan, add clean water to flush until no dirt flows out, then use kerosene or light diesel oil to flush the oil pan, add more cleaning oil [diesel oil] until the machine is full to the oil filler [or until the cleaning oil flows out, because some machine exhaust pipes are in the middle of the engine], use compressed air to insert as much as possible into the lower part of the cleaning oil for boiling flushing, so that the sediment deposited in the parts can be mixed with the cleaning oil, Stop and discharge as appropriate [check whether the valve rocker arm assembly is clean from the oil filler];
2. Remove the fuel injector, inject kerosene or light diesel oil into the cylinder, and wait until a part of it penetrates [let it flush the sediment in the piston ring gap],
Also use compressed air for flushing and then draw out the cleaning oil, add lubricating oil with lower viscosity, and add lubricating oil to the cleaned oil pan at the same time;
3. After the hydraulic oil tank inspection is completed, manually rotate the engine for more than ten cycles, extract the residual lubricating oil at the top of the piston, reinstall the fuel injector, and clean the fuel circuit;