Construction of the first of three massive concrete platforms to produce the massive oil resources in this North Sea field began in 1974.
The Statfjord A facility was constructed in great haste by Mobil on the basis of the Beryl A installation, built by the same operator for the UK continental shelf. Mobil intended to construct the other two Statfjord platforms to the same design, and the Storting (parliament) had approved the plan for development and operation (PDO) on that basis.
But when the B installation was presented to the Norwegian Petroleum Directorate (NPD) – then responsible for offshore safety – the concept was rejected. The regulator took the view that the overall risk presented by this integrated production, drilling and quarters facility was too high.
Mobil was asked to conduct a fresh review of the design concept, and preferably to opt for a separate quarters platform linked to Statfjord B.
The licensees came up with a new plan a year later, based on a detailed safety analysis – although it still involved a single integrated platform. But the design had been amended so that the living quarters were better shielded from fire and explosion, and positioned as far as possible from the process area. Work on Statfjord B prompted changes to the regulations, and the principles applied there have subsequently been used for all NCS developments.
Guidelines for safety assessment of platform concepts issued by the NPD in 1981 called for a risk analysis (concept safety study) at the conceptual stage for all new facilities on the NCS.
They established principles for conducting assessments and for the accident frequency to be evaluated as “dimensioning accidents”. When Norway’s new Petroleum Activities Act came into force in 1985, three key new regulations were also introduced which maintained the same principles.
These covered respectively overall provisions on safety in the oil and gas industry, the duty of licensees to utilise internal control, and the use of risk analyses.
Requirements for such assessments were concentrated during the 1980s on the conceptual design phase. But their scope was substantially expanded in 1990. This was achieved by a new regulation on the execution and use of risk analyses in the petroleum activity, which specified that they were to be used in every phases of the industry.
In force since 1 January 2002, the framework, management, facilities, activities, and technical and operational regulations currently govern Norway’s petroleum safety regime. The requirements related to risk analysis are to be found in the management regulations.