MSE-WE Joint Seminar: Douglas Fairchild, Strain-Based Design Pipelines, a Challenge for Materials & Welding Engineers

Abstract

Traditional pipeline design focuses on pressure containment (circumferential pipe properties); however, in some regions of the world, ground movements can subject pipelines to large longitudinal strains.  The term strain-based design (SBD) refers to pipelines for which the design loads and capacities are quantified in terms of longitudinal strain and the pipelines are designed to sustain a prescribed level of strain without rupture.  ExxonMobil has conducted a comprehensive program to characterize the tensile strain capacity of welded pipelines and to develop the necessary materials and welding technology for strain-based applications.   Design and materials engineering work has been conducted to enable SBD pipelines that can withstand longitudinal plastic strains of up to about 4%.  ExxonMobil has designed and/or installed 13 strain-based design pipelines ranging in grades from X60 to X80 and diameters 8" to 52".  This presentation will describe relevant materials and welding research and will highlight aspects of a SBD pipeline under construction in Papua New Guinea.

Bio

Doug joined ExxonMobil in 1982, worked for 7 years, took a leave to obtain his PhD, and then returned to ExxonMobil.  He has worked primarily in R&D focusing on the areas of welding engineering, physical metallurgy, fracture mechanics, and failure analysis.  Doug has conducted extensive work in the area of high strength steels.  His work has applications to the design and fabrication of structures used for the exploration and production of oil and gas.  These structures include pipelines, offshore structures, ships, pressure vessels, and liquefied natural gas facilities.  His work on, and the naming of, local brittle zones provided the basis for the industry standard API RP2Z.  Doug’s work also includes the patented welding technology that was used to construct the world’s strongest pipeline, X120, in 2004.  Doug has produced about 50 publications and 10 patents.