Chapter 16. ISO 19901-1 Petroleum and Natural Gas Industries — Specific Requirements for Offshore Structures — Part 1: Metocean Design and Operating Considerations

ISO 19901-1, the metocean design and operating considerations standard, has been providing the international oil and gas industry with requirements, guidance and region-specific data since it was first issued in 2005. It addresses the sourcing of metocean data, their analyses and extrapolation to long return periods, wave kinematics, joint probability considerations, metocean data (real time) collection and a range of other considerations.

Over the past few years, through a series of Joint Industry Projects and company led initiatives, the industry’s understanding of a range of specific metocean issues has advanced considerably, in particular in relation to crest height determination, wave kinematics, breaking waves, response based analyses and, most recently, how to address epistemic uncertainty within long term metocean extrapolations.

The introduction of these changes within the design and assessment of new and existing structures is likely to require some operators to revisit the basis on which they previously demonstrated that their structures deliver the required level of reliability.

This paper outlines the latest revisions to ISO 19901-1 which address the improvement in knowledge listed above. In addition, it presents new and revised guidance on the validation of Metocean forecasts for weather sensitive operations and region specific information.