Downhole Drill String Absorption Hydraulic Supercharging Device’ Working Principle and Analysis of Speed-Increasing Effect

It is known that ultra-high pressure water jet can effectively assist breaking downhole rocks and increase rate of penetration in drilling.Based on the research on drill string vibration performance in vertical well drilling,a JZZY-1 type downhole drill string absorption hydraulic supercharging device that can transform drill string vibration energy to drilling fluid pressure energy has been developed.A specially-made nozzle has been installed on the bit to create ultra-high pressure jet.The device reduces the axial vibration of the drill string and enhances the drilling fluid jetting velocity.Field test in 3 wells of Shengli Oilfield showed that the device can significantly increase drilling speed and effectively reduce the axial vibration of drill string with reliable performance,which also proves that it is feasible to increase the drilling fluid pressure energy by drill string axial vibration.This device deserves further investigation to meet the demand of safe and efficient drilling for deep wells.