Development and Field Application of a Compound Percussive Jet

To further enhance ROP in hard formations and to minimize stick-slip vibration of PDC bits, by combining the features of torsional impact devices and rotary drilling tools,a compound percussive jet for PDC bits which can output high-frequency uni-directional axial impact and reciprocal rotation impact simultaneously has been developed.Tests have been conducted to verify the feasibility and performance of the newly-developed compound percussive jet.The test results showed the innovative compound percussive jet could effectively provide axial impact and rotary impact simultaneously,and its impact frequency, impact power and pressure drop increased with the increase of pumping rate,and decreased with nozzle diameter increase.Field test results of Well Pu-4-32 showed with the application of the innovative compound percussive jet,the ROP of the well increased by 60.2% over the neighboring wells using the PDM+PDC bit compound drilling tools. During the test, the PDC bit had no stick-slip vibration, and the recovered bit didn’t lose any tooth. In conclusion, in addition to enhancing the ROP in hard formations,the innovative compound percussive jet could effectively minimize stick-slip vibration of and provide necessary protection to the PDC bit.