Fluidic-drag estimation in horizontal-directional drilling using the finite-volume method

摘要

This paper proposes a new method for evaluating hydrokinetic pressure and fluidic-drag changes during pipe-installation operations using horizontal-directional drilling (HDD). The method is based on applying the solution of eccentric annular flow using the finite-volume method (FVM) to the HDD case. Using MATLAB programming language, a computer code has been developed.Through an iterative procedure, the code determines the hydrokinetic pressure that satisfies the continuity equation within the bore, and returns the corresponding calculated fluidic drag. For verification, pull-back data of two actual HDD steel pipe installations completed in Alberta, Canada, have been used, and the estimated forces are compared against recorded ones in the field.The differences between the estimated and measured end pull-back forces are 40% and 7% for the two installations, while the corresponding values for the Pipeline Research Council International (PRCI) method are significantly higher, 238% and 85%, respectively.