Regarding the HDD slurry recovery system, the horizontal directional crossing construction method is relatively short at home and even internationally. Therefore, there is no perfect system for the horizontal directional crossing of mud solids and control that belongs to the industry. The mud solids control technologies at home and abroad are basically derived from the solid-control programs on the oil fields, and then simplified absorption. Therefore, the mud solids control process for non-digging and directional crossing is still very similar to that of oil fields. The main methods are dilution with water, sedimentation, and mechanical screening.

The first kind: The dilution method is to recover the mud returned from the traversing process to the storage tank, and then add water, bentonite, etc. The deployment of chemical drugs to the required mud properties also increases the amount of mud, so as to reduce the amount of mud. The solid content. The characteristics of this method are: simple operation and low cost. The disadvantage is that it does not fundamentally solve the solid content problem and cannot completely remove the solid content.

Second, the precipitation method is to dig one or more mud pits at the point where the traverse passes through, and at the point of entry, to store the slurry that comes back through the course of the process. The slurry is left for a period of time, and the natural phase sinks according to the physical material. , Then use the pump to suck mud slurry from the upper mud pit and re-inject it into the rig for recycling. This method is characterized by: simple operation, reduced energy consumption, low cost, the disadvantage is that the mud pit covers an area of large, long time precipitation, the separation is not complete, the solid phase remains in the bottom of the pit is not good to clean the environment pollution.

The third type: mechanical screening method. It is the solid phase control of returning slurry using our common mud recovery system. Mud recovery systems include vibrating screens, de-sanders, desilters, centrifuges, mud tanks and other equipment to form a system for grading the mud until the mud is used. Under normal conditions, mechanical screening is the most convenient and reliable method, and it also protects the surrounding environment.

With the development of directional crossing industry and people’s requirements on cost and environment, the method of mechanical screening will be used more and more widely in engineering. This will also be the law of the development of the industry.