Guidance on subsea spoolpiece metrology
- Informative Guidance
- Revision 2 - October 2025
This document provides comprehensive guidance on the planning, execution, and reporting of subsea spoolpiece metrology, with information on nine key metrology methodologies used to obtain dimensional data for the design and installation of subsea pipeline connections.
It covers the key principles, equipment and methodology, including:
long baseline acoustics
diver taut wire
digital taut wire
photogrammetry
INS
acoustically aided INS SLAM
sonar
static subsea LiDAR, and
dynamic laser scanning.
The document is intended as informative guidance for surveyors, engineers, and contractors, helping them select appropriate metrology methods and understand their impact on fabrication tolerances and operational safety.
Contents
Glossary
Introduction and overview
Subsea metrology planning and preparation
Subsea spoolpiece metrology survey methods
Subsea metrology deliverables
Further reading
Appendix A – Typical examples of metrology brackets
Appendix B – Typical examples of laser scanning targets
Appendix C – Comparison of subsea metrology systems
Appendix D – Summary of equipment requirements for metrology
Appendix E – Statistical confidence in accuracy reporting
Revision
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Rev. 2 - October 2025Title revised to include the word spoolpiece. Updates to each section to align with current technology and methodology. Appendices expanded to include an equipment summary and information on using statistical confidence in the reporting of accuracy.
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Rev. 1.1 - February 2024Update of page 2 and reference links; bookmarking (layout) improved; no change to content
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Rev. 1 - September 2017To include updated material
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Rev. - February 2012Initial publication