Drilling Method for Cohesive Soil in Construction of Friction Welding Drill Pipe

Classification:

Company News

Release time:

2019-08-09

【Summary Description】 Drilling Method for Cohesive Soil in Construction of Friction Welding Drill Pipe

摩擦焊钻杆

Friction welding drill pipeNeedleFor weak clay soil with low strength, high compressibility and small permeability coefficient, thixotropy and rheology, heavy hammer impact drilling and long/Short auger drilling, if the drilling environment is below the groundwater level, casing auger drilling or percussion rotary drilling can be adopted.

The drilling efficiency of heavy hammer impact is relatively low, and there is disturbance to the inner layer within a certain range near the bottom of the hole. Spiral drilling through the motor to drive the spiral drill pipe under the action of the pressure to make the drill bit rotary eat into the formation, the formation according to the spiral line step by step cutting, cutting the soil debris along the spiral blade back to the orifice, the method of drilling efficiency is high and no cleaning equipment. Long auger drilling diameter should be less1m, depth not exceeding15~20mBetween.

Short auger drilling is a non-continuous drilling rig, which is slightly less efficient than long auger drilling, and its aperture is more2 ~3mIn general, the drilling depth is less30m, the deepest is not more50m.

For hard plastic cohesive soil, the general spiral drilling is prone to burying or breaking of drill pipe when the soil viscosity is large, and the soil layer is disturbed greatly. Small rib drill bit and impact rotary drilling method should be used as far as possible.

Friction welding drill pipeThe impact rotary drilling technology is divided into three types: hydraulic, pneumatic and gas-liquid hybrid, which has the characteristics of high efficiency, low drilling speed, long drill life and few accidents in the hole.

Hydraulic impact rotary drilling is powered by high pressure formed by clean water or mud, and the drilling diameter is generally56-130mm, maximum not more400mm, drilling depth up800-1000m;Pneumatic impact rotary drilling is powered by high-pressure air, and the drilling diameter is65-228mmbetween, the maximum attainable762mm.Friction welding drill pipePromptDuring construction, slow drilling shall be carried out first, and then the drill bit shall be moved into the soil layer at medium speed, which can speed up the drilling speed and the lifting resistance of the drilling tool is small.

Key words:

weilida drill