Norman Wells pipeline permafrost and terrain monitoring: geothermal and geomorphic observations, 1984–1987

Abstract

A long-term permafrost and terrain research and monitoring program along the 869 km buried oil pipeline between Norman Wells, Northwest Territories, and Zama, Alberta, has been undertaken by the Geological Survey of Canada, in cooperation with the Department of Indian and Northern Affairs Canada. The two main program components are (1) the detailed quantification of changes in the geothermal regime and geomorphic conditions at instrumented monitoring sites and (2) general observations of terrain conditions and performance along the pipeline route. Pipeline operation commenced in April 1985. Observations during the first 2.5 years of pipeline operation indicate that, as expected, the pipe thermal regime and ground thermal regime have not yet stabilized in response to construction and operation. Warming trends in both mean annual pipe temperature and mean annual right-of-way ground temperature have occurred. Surface settlement in permafrost terrain is ongoing in the pipe trench as well as on the remainder of the right-of-way. Surface erosion has occurred, particularly at stream crossings and on low-angle slopes lacking erosion control structures. Key words: pipeline, permafrost, thermal regime, thaw settlement, surface erosion, instrumentation, Norman Wells, Mackenzie Valley, Canada.