In order to identify cost- and production-effective development concepts with the same functionality and robustness as subsea developments, the Norwegian Petroleum Directorate has initiated a study to evaluate different unmanned wellhead platform concepts.

Ramboll has performed a high level mapping of types of unmanned wellhead platforms installed worldwide and a more detailed assessment of the unmanned wellhead platforms installed in the North Sea.

Based on the characteristics of the platforms, they can be grouped into 5 types. Each type has been assessed with respect to complexity, operational features, well intervention, methods of access, manning frequency, man-hours on board and operational experience.

A review of and a comparison between the regulatory framework in Norway and neighbouring countries have been performed to evaluate, whether the regulations and guidelines support the development concepts of unmanned wellhead platforms.

The overall conclusion was that unmanned wellhead platforms can be cost- and production-effective development concepts in the more shallow part of the Norwegian Continental Shelf and that the regulatory framework is open to the concept.

However, in order to avoid discussions and individual interpretations of the regulatory framework, it is suggested to develop a guideline and/or a NORSOK standard for unmanned wellhead platforms.