Abstract:The paper briefly introduces the characteristics of rotary percussive drilling tool and the working principle, especially the combination of mechanical compact and hydraulic pulse excavating. The drilling efficiency comparison before and after the application of this tool in 12 block of Tahe oilfield and other different formations were analyzed. The tool was used in several wells of 12 block with efficiency increasing 25% at least to nearly 45%. Through the analysis, it was found that the efficiency increasing was not ideal in Halahatang formation of 12 block, but for those well sections and formations with poor drillability and low ROP by PDC screw drill assembly, the drilling efficiency was obviously improved. For example, the drilling efficiency in Kalashayi and Donghetang formations were improved up to more than 60% and generally above 30% with uniform drilling hour per meter and homogeneous rock breaking capacity.