The Design and Experimental Study of PDM Driven Rotary Percussion Drilling Tool

In order to improve the efficiency of rock-breaking in drilling operation, a new type of mechanical rotary percussion drilling tool driven by PDM has been designed, which combined high-speed PDM with high-frequency percussion device. On basis of structural design, a calculation model with single-time percussion power, percussion frequency and other key parameters has been established for vertical wells, and converted into a model calculation and analysis. Calculation results showed that single-time percussion power is only a function of cam stroke and WOB. When the drill string assembly is determined and has a certain length of greater than 500 m, and is composed of drill pipe with the size of φ127.0 mm, a single percussion power is positively proportional to the WOB, thus the percussion power can be adjusted by changing the WOB. The engineering prototype testing showed that the newly developed tools had a suitable structure, which can make high-speed rotation and high-frequency percussion to the bit that driven by the PDM, it has the potential to further improve its wear resistance.