Design And Research Of A New Percussive Rotary Drilling Tool

Nowadays percussive rotary drilling technology is one of the most effective solution to rock drilling problem in oil and gas industry.It takes advantages of impact drilling method and rotary drilling method,improves rock-breaking by exerting impulse shock over continuous drilling.According to previous research on percussive rotary drilling technology,this article introduces a new structure which overcomes the disadvantages of traditional tool in 3ways: the new one works at a lower frequency of 2.8Hz,releases higher impact energy of565 J and has a longer operating life of 442 h.The new percussive rotary drilling tool works like a valveless counter-acting hydraulic impactor.At the beginning of a single working circle,the drilling fluid turns the impeller to periodic circular motion,which affects the cam to go up and down repeatedly.When the cam goes up,the sealing blades are closed and the system holds the pressure to stretch the spring,so the hammer and the piston welding together with the spring are lifted,when the cam goes down,it presses the sealing blades to open and the system releases the pressure,therefore,the spring recovers and the hammer falls down.The circle ends up afterwards with the hammer hit the avail and transfer energy to the bit.This article gives a precise description on structure and working principle of the tool,improves the design of the impeller with the fluid-solid coupling method on FLUENT,builds a mass-spring model to illustrate the superiority of the spring structure and maximum theoretical value,estimates the operating life based on the creative work through Autodyn.In the end,this article comes up a blade sealing method to control the pressure more precisely compared with the old flow discharge structure.The other components are designed according to the oil industry standards.