Session: 02-04-2 CONSTRUCTION - Best Practices/Techniques

Paper Number: 134095

134095 - Case Study: Application of Best Practices for Pipeline Construction on Steep Slopes 

Abstract: 

In 2019, Coastal Gas Link started the construction of the 670 km-long 48-inch gas pipeline across the province of British Columbia. The project encountered many challenges, including but not limited to the construction across two mountain ranges, the Rocky Mountains and the Coastal Mountain Range. The latter, being in close proximity to the end of the pipeline is the subject of this case study. As part of the last 57 km of pipeline (Section 8W), as the pipeline approached the LNGC terminal in Kitimat and crossed the Coastal Mountain Range, it characterized a climb to the highest point at 1,400 m above sea level and descended to sea level. In this section, there were a number of steep slopes ranging in angle from 63 degrees to 15 degrees. Many of these steep slopes had unique challenges, based on topography, geohazards, construction windows and weather-related factors.  Each challenge contributed to the selection process for the most suitable method of steep slope pipeline construction.

 The steep slope pipeline construction techniques which were used consisted of:

-  Conventional open cut via trenching by blasting and ripping

-  Open cut using winch-supported equipment

-  Open cut with hydraulic sled using a top-down pipeline installation sequence

-  Raise bore of an inaccessible steep slope

-  Cable crane over a steep mountain side with a slope length of 1,373 m and slopes angles up to 58 degrees

The raise bore and the cable crane construction techniques were a first in Canada for pipeline installation, providing innovative and unique solutions to pipeline construction.

The objective of this case study is to provide an overview the various steep slope pipeline construction techniques, provide a discussion on the challenges and successes for each technique with a summary of the lessons learned. A summary of the safety practices developed and implemented will also be presented. 

Presenting Author: Arend Deelen TC Energy

Presenting Author Biography: Arend has over 26 years experience successfully building and motivating dynamics teams, delivering projects ranging in size from TIC $5MM – $7Billion from Conceptual through to Construction, & providing operational support by applying industry best practices for a range of projects that include Hydrocarbon, Carbon Capture, Wind farms, and Heat/Energy transfer system, in North America, Europe, Africa, Asia, and Middle East.

Authors:

Arend Deelen TC Energy
Clayton Van Megen Stantec Consulting Ltd.
Carrie Murray Stantec Consulting Ltd.
Colby Smith TC Energy
Riley Bartel TC Energy
Jesse Bajnok TC Energy