Technology Approaches for Northern Pipeline Developments

Traditional pipeline technology will be severely challenged as developments continue in arctic regions. Cost-effective solutions to these challenges can be found through innovative technology and its implementation. TransCanada PipeLines has been involved in a series of technology programs that have been implemented in challenging climates including permafrost. In addition TransCanada is also involved in ongoing programs whose aim is to reduce the cost of Northern pipelines whilst at the same time provide structural assurance and reliability. This paper will describe the overall approach to developing cost-effective solutions and how these programs are interconnected. The topics to be covered will include the approach to strain-based design and how TransCanada has been taking advantage of the approach in its implementation of higher strength steels. The work also includes the approach taken in terms of the design for the effect of mismatch between the pipe and weld metal properties. The strain-based approach is also being extended to a structural reliability methodology and the work conducted to date will be briefly discussed. A significant portion of the design of a Northern pipeline relies on the development of a frost heave-thaw settlement methodology and the current philosophy and its validation will be discussed. A prime consideration of the regulatory bodies is the assurance of structural integrity and fracture control plans. The work currently ongoing at TransCanada on fracture safe behaviour will be discussed. Additional discussion on construction related topics will be covered including welding, buoyancy control, directional drilling and trenching.