<p>This paper describes a multi-pronged continuous improvement effort to manage the spans of a deepwater pipeline, where even without wave action the currents are strong enough to move sediments, initial and propogate&nbsp;seabed scouring and&nbsp;leading to constantly changing spans.&nbsp; The&nbsp; continuous improvement effort includes: (1) using strakes rather than intermediate pipeline supports to suppress VIV, since the latter proved not to be a long-term solution, (2) using partial rather than full strake coverage of spans and developing tools to quantify the level of strake coverage that is required to achieve&nbsp;target remaining life&nbsp;, (3) improving estimates of soil stiffness and damping, and tools to handle amplitude-dependent soil stiffness and damping, (4) performing pluck tests of the operating pipeline by pulling it laterally at midspan with the ROV until a weak link connecting the ROV to the pipe breaks, whereupon the resulting motion of the pipe is recorded with accelerometers, (5) developing tools that allow fatigue damage to be estimated and accumulated for every location along the pipeline (6) sponsoring a joint industry program by DNVGL to quantify the effect of seabed proximity and trench effects on VIV.&nbsp; This paper will provide an overview of these activites, with emphasis on recent results covering items (2-4) above.</p>

Deepwater Span Management on a Mobile Seabed

Paper Proceedings: https://asmedigitalcollection.asme.org/OMAE/OMAE2021/volume/85116

OMAE 2021

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