Parameters optimization of release force under top-excited in stuck pipe

Abstract

Stuck drilling accident is one of the most frequent accidents in the drilling process. The operation time of release drilling is also one of the most time-consuming operations in workover process. In recent years, the technique of release, by drilling string resonance, has been introduced into the drilling field, greatly reducing working hours and improving efficiency. In this paper, the release force’s sensitivity analysis is introduced to optimize the design parameters of the device and the working parameters of the release process. First, the pipe vibration behavior under the surface vibration agitator’s action is analyzed, and the natural frequencies are obtianed analytically. Second, based on Rayleigh damping and specific boundary conditions, the damping effect equation of drilling fluid is derived under drill string vibration. Finally, the influence of structural parameters, environmental parameters, and working parameters on the clamping force is obtained. This paper casts carry through the theoretical interpretation of the release force’s sensitivity analysis by stuck release mechanism and is of significance to optimize the stuck release operations.