Due to arctic permafrost conditions, pipelines in Alaska's North Slope oil fields are located on supports approximately 5 feet above the tundra, with spans ranging from 40 to 60 feet. Steady arctic winds blowing across the flat topography of the region often induce vertical pipeline vibration. Although the vibration amplitudes are typically quite small, the accumulation of vibration cycles can induce fatigue damage, especially in pipeline field welds. A series of pipeline wind-induced vibration studies undertaken at the Kuparuk oil field are summarized in this paper. An introduction to wind-induced pipeline vibration and observations from a field measurement program are presented. Results and implications from full profile fatigue tests on typical pipeline field welds are then discussed, followed by a discussion of the performance of promising mitigative systems. The design and analysis of pipeline vibration dampers suitable for field-wide application at Kuparuk is then summarized.
Due to arctic permafrost conditions, pipelines in Alaska's North Slope oil fields are located on supports approximately 5 feet above the tundra, with spans ranging from 40 to 60-feet. Steady arctic winds blowing across the flat topography of the region often induce vertical pipeline vibration. These oscillations are vortex induced cross-flow (vertical) vibration caused by (horizontal) wind flow across the pipelines. Although the amplitudes of vibration are typically quite small, the accumulation of vibration cycles can, induce fatigue damage, especially in pipeline field welds. Several analytical and experimental studies were undertaken to better understand and control the pipeline vibration phenomenon. A project overview is presented in (Hart, 1992). The pipeline wind-induced vibration (WIV) studies undertaken at the Kuparuk oil field are summarized in this paper. In Section 2, the results of a field measurement program are presented. In Section 3, the correlation between experimental and analytical results is discussed.
