Sonic Drilling with a Cavitation Hydraulic Vibrator: Theoretical Computation of the Energy Performance and Rate of Penetration

Abstract

A new approach to the numerical analysis of the dynamic interaction of rock and the drill string structure for sonic drilling of wells by using a cavitation hydraulic vibrator is proposed. The approach is formulated on the basis of the developed mathematical model of the “drill string - rock” dynamic system. The parameters of mud oscillations and mechanical vibrations of the drilling tool, as well as oscillation power at contact interaction of the bit with the rock, were determined. It is possible to establish the resonant frequencies of drilling tool mechanical vibrations and the rock, necessary for an increase in rate of penetration. The penetration rate was calculated in two ways: using the concept of hydraulic vibration power and drill vibration power. It has been established that the use of a drilling tool with a cavitation vibrator is more effective compared to other means of exciting the drilling tool vibration load. The intensification of the rock destruction process when drilling with a cavitation hydraulic vibrator is carried out due to an increase in the vibration energy transferred to the rock and a decrease in the energy intensity of the rock destruction process in resonant drilling modes.