Following a study that looked into the benefits and disadvantages of wellhead platforms, the Norwegian Petroleum Directorate (NPD) has taken a positive view of unmanned wellhead platforms (UWHP) as an alternative development concept to subsea developments.
Rambøll Oil & Gas has submitted a study, commissioned back in October 2015, which sheds light on the advantages and disadvantages of unmanned wellhead platforms.
According to the NPD, the conclusion is that unmanned platforms may provide efficient development solutions in terms of costs and production for shallow water developments on the Norwegian shelf.
The study was commissioned because the Norwegian Petroleum Directorate considers concepts of this type to be an important contribution to good resource utilisation, the agency explained.
An unmanned wellhead platform is a facility resting on the seabed where the wells are placed on the platform deck. The concept is an alternative to subsea wells with wellheads situated on the seabed. There are various types of unmanned wellhead platforms – from simple facilities to more advanced solutions which include e.g. process equipment. Access may be via gangway from vessels, while others have helicopter decks.
In December 2015, Statoil and its partners submitted a Plan for Development and Operation (PDO) for Oseberg Vestflanken 2 in the North Sea, where the development concept entails an unmanned wellhead platform, a jack-up rig and a support vessel. This facility does not have a helicopter deck.
Topics addressed in the study include:
– Basic types and locations for unmanned platforms;
– Experience from operation and maintenance of unmanned platforms;
– Regulations and framework conditions, Norwegian shelf and comparable continental shelves.
Development of these types of concepts comprises both technical solutions and regulations. Amendments to the regulations are handled by the Petroleum Safety Authority Norway.
The report is available on NPD’s website: Unmanned wellhead platforms – UWHP summary report.