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§ 15 Preliminary surveys

Before facilities are placed, the necessary preliminary surveys ensuring prudent installation, use and disposal of the facilities shall be carried out.
Section last changed: 01 January 2011

The following standards should be used in connection with preliminary surveys:
  1. the NS-EN ISO 19901 Part 1 standard for surveying natural conditions,
  2. Section 3 of the DNVGL-ST-F101 standard should be used for route surveys,
  3. Chapter 7.9.1 of the NORSOK N-001 standard for geotechnical surveys, with the following addition: a quaternary geological description should be prepared if in a new area,
  4. Chapter 5.7.2 of the NORSOK D-010 standard in the event of shallow gas surveys,
  5. subsidence is calculated with the aid of geological models. As such models are associated with significant uncertainty, an upper 90 percentile should be used for the subsidence estimate. Consideration can be given to the stabilising effects of injection of gas or liquids.
If the surveys show that the likelihood of placing foundations above formations that contain gas is greater than one per cent, another location should be chosen.
In addition to preliminary surveys, baseline surveys shall be carried out as mentioned in Section 53 to map the environmental status.