A case study of pipeline route selection and design through discontinuous permafrost terrain in northwestern Alberta

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:434153

Wiechnik, C; Boivin, R ^[1]; Henderson, J; Bowman, M ^[2]

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1. NOVA Gas Transmission Ltd., Calgary, Alberta (Canada)
2. Associated Mining Consultants Ltd., Calgary, Alberta (Canada)

As the natural gas pipeline system in Western Canada expands northward, it traverses the discontinuous permafrost zone. As the ground temperature of the frozen soil in this zone is just below freezing, it can be expected that within the design life of a pipeline the permafrost adjacent to it will melt due to the disturbance of the insulating cover by construction activities. Differential settlement at the thawing frozen/unfrozen soil interfaces gives rise to pipeline strain. Based on the calculated settlement and resulting strain level, a cost effective mechanical or civil design solution can be selected to mitigate the differential settlement problem. Since these design solutions can be costly, it is desirable to combine them with a pipeline route that traverses the least amount of discontinuous permafrost terrain while minimizing the overall length of the pipeline. This paper will detail the framework utilized to select the routing for a package of pipeline projects in northwestern Alberta. It is believed that the increased front end effort will result in lower operating costs and an overall reduced life-cycle cost. This basic design methodology can be applied to any project that traverses discontinuous permafrost terrain.

• OSTI ID: 434153
• Report Number(s): CONF-9606127--; ISBN 0-7918-1767-9
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ALBERTA
GEOPHYSICAL SURVEYS
LIFE-CYCLE COST
NATURAL GAS
PERMAFROST
PIPELINES
ROUTING
SOIL MECHANICS
SOIL-STRUCTURE INTERACTIONS
STRESS ANALYSIS
TRANSPORT