A theoretical solution to predict pulling forces in horizontal directional drilling installations

摘要

The paper presents a model for predicting pulling forces during pulling back phase in horizontal directional drilling (HDD) projects. The analytical method follows the method proposed by Polak et al. (2007) and expands it in three aspects: (1) the surrounding soil is described by Winkler model and it constitutes an elastic support for pipe during pulling back, (2) the non-Newtonian properties of slurry is considered and (3) the resistance exerted on drill string is considered and the pulling force at rig is calculated. Components of the pulling force are calculated considering the effect of pipe-soil interaction in cross section and the coefficient of chock effect, which can be calculated using the finite element analysis is defined to indicate the clamping effect of soil on the pipe. A computer program PipeForce Version1 was compiled according to the given method. A comparison of HDD experimental data and predictions of pulling forces are presented.