Effect of the Nozzle Distribution in the Drill Bit on the Cleaning of a Well Bottom.

The results of static and field tests are presented which show the advantages of using drill bits with an asymmetrically arranged rinsing system and hydromonitor nozzles which are differentiated with respect to function. In this type of drill bit part of the flow is directed into the peripheral zone of the well bottom, exerting a dynamic pressure on it, another part of the flow travels along a tangent to the well bottom and creates an intensified transverse flow which washes away the drilling mud from the center to the periphery, while the third part of the flow is used to accelerate the motion of the flow in the interannular space, thus creating an ejection action on underlying layers of the fluid in the bottom region.