Dynamics experimental study of column in the well

Abstract

Mechanical analysis of bottom hole assembly(BHA) is the basis of well trajectory control technology. Considering the displacement and force boundary conditions of drillstring and testing axial excitation force of bottom column, axial acceleration of head column, transverse displacement of columns and collision and contact forces between inner columns and outer pipe, dynamics experimental device of column-liquid interaction is built to do two kinds of test: the column vibrating test under the conditions of different vibrating frequency and different axial excitation force and the column rotating test under the conditions of different axial excitation force, different rotating speed and different flux. The experimental results show that the changes of vibrating frequency and the flow has little effect on axial vibrating force of bottom column and radial displacement of column, but the existence of the liquid will reduce the axial force amplitude of bottom column; With the speed increased, radial displacement of the column and the segments of the collision and contact column between the column and the pipe increase and the columns have the phenomenon of multi-segments swing. It is to provide the device and means to study dynamics movement rules of rotating column in the pipeline.