It's based on the principle of water jet cutting. It gives the combined effect of water jet cutting and surface drilling operation to overcome the drilling problems by this design on the basis of anticipation of potential hole problems, such as drill hole deviation and high hardness rocks.

Design:
It is designed to create synchronization between leading/cutting edge of the drill and water jet nozzles on trailing edge, that helps in effective drilling operation over less time. Hull is provided to push away the debris; it is also intended to guide the drill.

Operation is illustrated in the first diagram.
Drill bit consisting of hull, leading/cutting edge and trailing edge with nozzle is fed into the surface by means of conventional hydraulic or pneumatic feeding mechanism by means of drill pipes. Pressurized water is pumped into drill pipes by means of external high pressure pump. Attachment and detachment technique of these pipes are similar to conventional drill pipes. In Additional each drill pipe consist of two nos of one directional valves, to maintain constant pressure without continuously running High Pr. Pump. Hence once water is pumped into drill pipe the valves maintain set pressure in the pipe which is less than valve opening pressure.(say 110MPa is set pr. that valve can keep itself closed and beyond this it will tend to open) It will save the operating cost of high pressure pump.

This high pressure water enters into drill bit where its pressure energy converted into high velocity jet by means of nozzles which are located in trailing edge. This orientation helps to cut down the hard rocks before contacting with cutting edge, which may damage the cutting edge and stuck the drilling bit. High hardness rocks such as Granite & Diorite can no longer create failures due to water jet cutting. Water jet will cut these rocks into pieces that less cutting force will be needed for crushing. Water remained in bore will cool down the drill bit. This water will also put out the debris from bore then it can be recirculated after filtering process.

While drill bit is having two sections of different diameters. The bottom one is with small diameter to create center drill effect and upper one is with large diameter that will create same effect as expanding bore. This will minimize the driving potential required. While cutting teeth are roller type teeth instead of fixed teeth shown in figures.
Hull will generate extra crushing effect and considerably guide drill bit with less deviation because of its shape.

This concept is intended towards creation of an effective and theoretically precise surface drilling technique which will consume less time than others.