Normal circulation drilling works:

Drilling rig is driven by the motor driven rotary drill pipes, drill bits, Rotary drilling, at the same time to activate the pump pressure to make it through the rubber tube of mud in the mud pool, water cannons, hollow drill pipes, then drill out both sides of the lower part, scouring hole, and along the hole drilling of mud mixed with slag and walled up by the orifice discharge, into the pits. After drilling residue deposits, clean mud will flow back to the mud pools, so forming a working cycle.