NASTT Abstract

Longitudinal & Circumferential Pipe Stress in Horizontal Directional Drills

Authors:
Brent Goerz, P.Eng. CCI Inc., Edmonton, Alberta
Justin Taylor, P.Eng. CCI Inc., Edmonton, Alberta
Micheal Martens, TCPL, Calgary Alberta

Abstract
As pipelines are pulled into a borehole using the Horizontal Directional Drill (HDD) method, longitudinal stress and circumferential stress are imposed on the pipe section due to fluid forces on the external surface of the section. As the pipe section is pulled into place, the section also undergoes a strain as it is forced to conform to the borehole geometry. This condition is modeled for both the installation and the eventual operation of the pipeline system. Currently, the analysis method developed by Pipeline Research Council International (PRCI) – (Installation of Pipeline by Horizontal Directional Drilling – An Engineering Design Guide PR-227-9424) remains the most prevalent industry-wide standard for the design of HDD installations. This paper presents these theoretical calculations and compares the results with recent measured data from the CCI Strain Measurement Tool.

This review includes standard theoretical modeling using PRCI and comparing it to measured pipe strain data using a Strain Measurement Tool designed by CCI Inc. (CCI). This data shows the correlation between the modeled stress and actual measured strain, and presents some opportunities that may exist in many projects for a more aggressive design which would significantly reduce the overall length, complexity of the project, risk and the cost of an HDD crossing. This information may also make some crossings geometrically feasible, where they may not have been previously.

Publication Date: 2014

Presented at: 
NASTT’s 2014 No-Dig North Show, Orlando, Florida
April 13-17, 2014
Paper Number: TM2-T2-02

For more information on this article, please contact Brent Goerz (brent.goerz@ccisolutions.ca).