The paper has considered the particular features of the movement of a long vertical string in a borehole, filled with a thixotropic liquid. A model has been developed to allow for the effect of inertia of the liquid and string on the hoisting-descent of strings. Also, the effect of the total elasticity of strings was not ignored. The system of traditional differential equations obtained has been numerically analysed. It has been shown that the stationary movement of strings may lose its stability, due to the destruction of the structure of the liquid. In this case, periodic and chaotic self-oscillations are excited in the system.
|Number of pages||7|
|Publication status||Published - Apr 1994|