Research On Impact Resistance Performance Of PDC Cutters

PDC bit has been suitable for drilling soft to medium hard homogeneous formation effectively so far, but the structure failure of cutters often leads to the serious decreasing of ROP when drilling in heterogeneous formation, such as soft- hard interbedded formation and gravel formation. This paper mainly studied the law when the PDC cutters have been subjected to the impact load and explored the main factors that influenced the impact load. Through the impact load text on the PDC cutters, I had found that these factors were the angle of rake, cutting depth, cutting rate and hardness of rock etc. These factors all have an important effect on the impact load and the laws between these influential factors is as follows: the axial impact force and tangential impact force are in a linear relationship with cutting rate, in a linear relationship with cutting depth, in the quadra tic polynomial relationship with the angle of rake and in the logarithmic relationship with hardness of rock. Then by using multivariate nonlinear regression method, I establish a PDC cutters impact load forecasting model that can be used to calculate and predict the impact load values on PDC cutters quantitatively in the actual drilling process. In addition, during the research process, the author designed the PDC cutters impact resistance test device and put forward a set of PDC cutters impact resistance test methods and procedures. They can be widely applied to testing and evaluating impact resistance performance of different specifications PDC, providing a scientific basis for improving the impact resistance of PDC cutters.