Optimal Design Of Hydraulic Structure For Jet Mill Bit

Shale gas as a clean energy,in recent years has been more and more extensive attention.However,the development of shale gas is still facing the problem of high drilling cost caused by low ROP of the whole well.A new type of PDC bit-jet mill bit was developed,which provides a new tool and new technology to solve this problem.In this paper,the research methods and research status of hydraulic structure of PDC bit are studied,and then the hydraulic structure of jet mill bit is optimized and designed from the aspects of simulation experiment and numerical simulation.The simulation experiment was conducted to verify the two main functions of reducing the bottom hole pressure and crushing cuttings.The simulation results show that the effect of reducing the bottom hole pressure is significant under the specific experimental conditions,but the effect of crushing cuttings is not obvious.Before the numerical simulation,the physical model of the jet mill bit is optimized first,and the effect of the flow ratio on the bottom pressure is discussed.Through the numerical simulation analysis,it is found that the best effect of reducing the bottom hole pressure can be achieved when the flow ratio is 1.2.This paper has reference significance for the optimization design and engineering application of jet mill bits.