Under the action of atmospheric pressure, the circulating fluid flows from the sedimentation pool through the back ditch along the ring gap of the well hole to the bottom of the well, because at this time the turntable drives the drill pipe, drives the drill bit rotation to drill, the negative pressure established by the mud pump draws the debris mud into the drill pipe cavity, and then rises to the tap, through the mud pump draininto into the sediment pool, The precipitated circulatory fluid continues to flow into the wellbore, so that it is so repeated that a counter-cycle drilling work is formed. Mud or water enters from the drill pipe and flows out of the wellhead. For a positive cycle drilling machine. Mud or water is sucked out of the drill pipe and flows in from the wellhead. For anti-cycle drilling machines. Positive and negative cycle refers to the drilling fluid (mud or water) in the drilling machine in the circulation way said, drilling machine drill bit in the drilling time will produce slag, slag, etc. , through the positive and negative cycle can be carried by the mud these slags to the ground, and then after precipitation after the sedimentation of the mud back to the drilling. This non-stop cycle, and finally into a hole.
The reverse cycle can lead out slag with a large diameter. Large-scale drilling project can not be separated from the use of drilling machine, its good performance greatly improve the speed and efficiency of drilling, especially in remote areas of the use of drilling machine more extensive population.