Following broad industry consensus, Standards Norway (SN) has published the fourth revision of subsea standard NORSOK – U001.
According to SN, the NORSOK U-001 will be the most updated international available standard for subsea oil industry.
It provides a method for design of subsea equipment to withstand loads in the vertical axis during drilling and well intervention. It also includes guidance on how to combine various subsea equipment and will maintain a uniform safety margin on a project specific basis.
To the industry it provides: Standardized design loads; Fast track delivery, based on standardized design loads; Improved system structural integrity; Uniform structural safety margin; Link between structural design and material property requirements; Practical guidance.
This revision replaces revision 3 from 2002. The basis for this NORSOK standard has been the previous version of U-001 combining industry experience over the last 10 years. The standard integrates relevant parts of ISO 13628 Petroleum and natural gas industries – Design and operation of subsea production systems combined with updated knowledge and best practice from fishing, riser loads and design of subsea wellhead and tree equipment. Approximately 15 experts from the industry have been involved in the revision and 22 national and international stakeholders gave 326 comments to the draft.
The main changes are:
– Model tests are acceptable and the Table 1 Fishing gear loads have been updated;
– Annex A Standard design loads for subsea wellheads and templates (informative) is completely re-written, based on industry reports and field experience;
– Annex B Materials requirements for subsea equipment (informative) consists additional considerations with respect to ISO 13628-4 and -7 to ensure improved system structural integrity and uniform margins of safety.