The Oooguruk offshore Arctic flowline system design, construction and operation satisfy the unique conditions presented by this shallow water Beaufort Sea location. The bundled 3-phase 12 × 16-inch pipe-in-pipe production flowline, 8-inch water injection, 6-inch gas lift/injection and 2-inch diesel fuel flowlines were installed along with power and communications cables offshore the North Slope of Alaska during 2007. The maximum water depth along the flowline route was only 7 feet but the location immediately offshore the Colville River Delta presented challenges with the flowline loading conditions, thermal interactions with the local environment and construction procedures. Key features of this flowline system include addressing flow assurance requirements for combined offshore/overland sections, strudel scour, subsea permafrost thaw consolidation, upheaval buckling, limit state design for bending, winter construction procedures and flowline leak detection systems. The subsea power cables consisted of separate cables for each conductor in order to be compatible with trucking all materials to the remote site. The dual fiber optic communications cables are being utilized with a distributed temperature sensing system to monitor the flowline burial conditions and supplement the multiple flowline leak detection systems.
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