Abstract: In order to further improve the drilling speed in hard formation of medium deep wells in Dagang Oilfield,the self-oscillation impact drilling tool was used in 8 wells in 4 blocks including Duanliubo,Kongnan 4,etc.The test results show that the tool,stable in performance,and reliable in quality,increased the ROP by 14.20%-132.63%.This showed that the application of the self-oscillation impact drilling tool could basically meet the requirement of improving ROP,but in order to take full advantage of the tool,the best applicable conditions of the tool should be further investigated.