Seismic Design of Facilities for the Oil and Gas Industry, Risk Based Seismic Design Criteria and Upgrading of Existing Facilities

The design of facilities to resist seismic loads requires selection of an appropriate safety level. This paper will discuss the requirements of different international standards and will suggest that the criteria might be established on the basis of a quantitative risk analysis. The paper will, furthermore, discuss the experience oil companies have gained through working in Norway and North Western Europe in designing facilities to withstand the relevant seismic loads. Although this area of the world is an intraplate area with relatively low seismicity, it is suggested that the experience gained in using risk based seismic design criteria and quantitative risk analysis could be of value to those working in more seismic regions of the world. The paper will mainly refer to onshore terminal facilities on the Western Coast of Norway, which is the area of the North Western Europe with highest seismic hazard, and to offshore platforms in the Northern North Sea. Finally, the paper will present considerations related to upgrading of existing facilities with particular emphasis on facilities in the oil and gas industry.