What is the difference between bentonite mud and general mud? Why should the bored pile be made of bentonite mud?
During drilling, the change of electrolyte concentration requires little change in viscosity and thixotropy of the mud, which is not available in general mud. Therefore, bentonite slurry should be used in bored piles!
Then from the mud pool to the borehole. Limitation of strata in the water into the hole. And the impermeable layer is formed on the hole wall to prevent water from drilling fluid into the formation. This thin layer of impermeable layer has a certain strength and toughness. The only way to prevent borehole collapse and drilling in the corrosion process by grinding drill caused.
In the process of rotary drilling hole to keep the mud, mud through a hollow pipe from the pump reaches the bottom of the hole, the outflow from the bit gap through the annular space wall and pipe up to the surface and into the mud pool. Its function is to remove cuttings discharge gas
