The application of X100 to gas pipeline projects

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 and its partners have been involved in a series of technology 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 utilizing X100 technology and how these programs are interconnected. The topics to be covered will include the approach to the development of X100 pipe technology and its relationship to strain-based design. The paper will describe the integrated approach to limit states design and the key elements affecting strain demand and strain capacities with respect to material engineering and structural engineering, and how TransCanada has been taking advantage of the approach in its implementation of higher strength steels. 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 behavior will be discussed. The work also includes the approach taken in terms of the design for the effect of mismatch between the pipe and weld metal properties, and recent improvements in mechanized welding. The strain-based approach is also being extended to a structural reliability methodology and the work conducted to date will be briefly discussed. The paper will describe two recent X100 projects that have been designed and constructed in Alberta covering summer and winter approaches, and planned future projects implementing changes to pipe specification to account for strain-based designs. (AU)