The Subsea Drake Pipeline: A Challenging Case Study to Check Design Effectiveness Against Drifting Ice Action

Abstract

The Drake pipeline is located offshore Melville Island, in the Canadian High Arctic. It was built on-site in 1977-78 and connected to a natural gas production well, which operated for only a few months. The well was plugged in 1995 and the pipeline was abandoned. The pipeline extends from the shoreline to the wellhead located about one kilometer offshore to a water depth of 55 meters. It is buried at the shoreline crossing, to a target depth of 1.5 meters below sea bottom. A system to generate a frozen soil shield was also devised for further protection against drifting ice. Also, a berm made from ice and gravel was built at the water line. Field investigations could prove highly instructive to assess the state of the structure, and provide guidelines for design of future pipelines in high risks areas. However, significant technical and logistical challenges would face that venture, namely a ‘no physical contact’ (with the pipeline) restriction from the property owner, which leads to difficulty in understanding what has occurred to the pipeline beneath the soil, and a propensity for the region to be covered with a very thick ice cover.