Rotary drilling rig is to prevent and solve the hole collapse is not saved  

When the rotary drilling rig works in the quicksand layer, it is necessary to prevent the formation of the collapse hole, and also to prevent the vicious circle of continuous collapse. To do this, you should work in accordance with the following methods.

1, reasonable allocation of mud, according to the characteristics of the flow plastic formation, need to configure high viscosity, medium density slurry for wall protection.

2, set holes on the drill bit to ensure that the drill bit up and down mud flow during drilling, so as to prevent the vacuum phenomenon in the process of lifting drilling;

3, keep the mud level higher than the groundwater surface 2 ~ 3M, can be increased by protecting the cylinder or around the hole set clay dam to achieve;

4, adjust the operation mode: control mud level, and in the drilling process always keep away from the top edge of the protective tube 30 ~ 40cm. (especially when lifting a drill). Drill to the soft soil and sand, soft soil and sandy soil is easy to collapse hole formation, operation should pay attention to reduce the wall erosion and disturbance, operation method and strictly follow the three principles namely: slow, drilling and drilling speed is slow, the speed of strict control of drilling tools, to reduce the disturbance little mud on the hole wall, and leave enough time for the formation of mud; ground observation: pay close attention to the mud level.

When the mud level decreased suddenly and a large number of foam gush, can determine the local collapse, should immediately stop drilling and ensure the drilling bucket bottom in open, slowly lifting drill, to avoid disturbance caused by the two collapse; local collapse accidents: when there is a partial collapse, and puts forward to drill mud into the hole, pouring enough clay into the hole with the excavator, then lower the bit reversal of compacted clay, edge pressing inversion, and drilling method stated above to be stable.

Generally speaking, to solve the hole collapse mainly lies in the prevention, rather than to save you, remember?