Dynamic Model of Pipeline During Pulling in Directionally Drilled Hole

The most important problem in pulling pipeline in the directionally drilled hole is overcoming of the soil resistance. This paper presents the 2-D model of contact interaction between the pipeline and soil as well as a numerical method of calculation of the pipeline vertical displacement and drag while pulling. The model is based on dynamic equation of lateral forces. Using this model it is quite easy to take into account nonlinear contact interaction of pipeline and soil in terms of both contact force and friction drag as well as a convective nature of the lateral load propagation at an axial motion of pipeline. Based on the suggested numerical model, a computer program was developed to improve an accuracy of pulling process analysis with moderate computer time needed. The developed program was applied to analyze and select parameters of the Lisichansk-Tikhoretsk oil pipeline in the tunnel under the river of Don. Calculations provided the updating of pulling process parameters and identification of those tunnel intervals, which might be challenging with pipelining.