Study On Radial Rotary Jet Drilling Of Coiled Tubing

Coiled tubing radial rotary jet drilling is a high-speed being developed new engineering technology, Its target of service mainly are ultra-short radius horizontal wells and the wells that is difficult to be drilled by large mechanical drilling machines. In this paper, to meet the demands of drilling horizontal wells, combined with rock broken model and the broken mechanism brought by jet, a new type of rotary jet structure is proposed, and the drilling speed is improved greatly.The paper analyzed the broken mechanism of rock, studied its broken model, and analyzed the broken mechanism brought by rotary jet. On the basis of analyzed, combined with the existing way of rotary, a new type of modular rotating jet nozzle is designed, and analyzed the nozzle’s effects of increase rotary, the forced deformation, etc. Then combined with related engineering requirements, described the process of coiled tubing radial rotary jet drilling. Finally, the outdoor experiments have been carried out to verify.The new radial rotary jet drilling system greatly improved the speed of jet drilling, more than two times the normal speed, about3-5m/s, achieved the automatic feed function of spray head, and the reasonable allocation of the jet energy.