Unlocking the benefits of long-term pipeline-embedment processes: Image analysis-based processing of historic survey data

An image analysis-based method for retrieving high-resolution bathymetry data from historic pipeline inspection video is detailed. The resulting time-dependant bathymetric datasets are used to inform an improved understanding of pipe-soil and pipe-soil-fluid interaction. This allows better management of existing pipelines and improved design of new pipelines. The pipeline and seabed positions are extracted automatically from the survey video, spurious points removed, the data scaled, and interpolation applied. The data can then be projected in various forms, for different applications. Drawing on field data from Australia's North West Shelf, applications of the method are described. For pipeline design, it is shown how improvements in on-bottom stability and changes in seabed friction can be quantified for mobile seabeds and through buckling sections of pipeline. This approach unlocks advances in existing design practice by providing quantification of the effects of seabed mobility. The processes and mechanisms that lead to through-life changes in pipeline embedment, soil support, and hydrodynamic shielding can be quantified, allowing design to move beyond the usual assumptions of a pipeline embedment that is invariant in time and space.