Abstract:

In view of the coupling vibration of key components in the drilling process of the downhole drilling rig, the downhole drilling rig was simplified into a multi-degree-of-freedom and multi-elastic system. The dynamic model of the drilling process of the downhole drilling rig was constructed based on the Lagrange equation. The displacement and vibration acceleration of the drilling rig during the drilling process were analyzed, and the rigid-flexible coupling dynamics of the drilling process were solved by the dynamic analysis software ADAMS. The post-processing program PostProcessor was used to perform the Fourier transform on the acceleration curve of the drill pipe under vertical and inclined conditions, so as to obtain the corresponding power spectral density distribution and analyze the dynamic response characteristics of the drill pipe under vertical and inclined conditions. The research shows that due to the influence of coal rock mutation and other factors, there is an instantaneous peak response of drill pipe acceleration in vertical drilling, but it does not affect the overall vibration law. The vibration acceleration of the inclined drilling process is stronger than that of the vertical drilling process, and the maximum vibration accelerations of the drill pipe in three directions are 4, 100, and 80 m/s², respectively.

Key words: downhole drilling, drilling process, dynamics model, response characteristics, vibration