In today’s competitive environment, oil and gas pipeline companies must search for materials and construction methods that reduce project capital costs while maintaining the quality and integrity of the pipeline. Pipeline buoyancy control can be a major cost of large diameter pipelines, particularly for routes that cross wet terrain.
In 1999, Enbridge Pipelines (Athabasca) Inc. constructed the 541 km NPS 30 Athabasca Pipeline from Fort McMurray to Hardisty, Alberta. Because of the substantial areas of muskeg that the pipeline route traversed, Enbridge selected a pipeline anchor system as the primary means of buoyancy control for the project. This new technology saved greater than an estimated $12 million CDN when compared with the cost of concrete set-on weights, which is the traditional method of controlling buoyancy of pipelines in North America.
This paper describes the design of the anchor system selected for this project, details the calculations performed to determine anchor spacing, documents the challenges which were overcome during installation, and analyses the cost savings which were achieved by the use of this technology.