Certification of new concepts

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Abstract Certification of offshore installations will be considered in the overall perspective of safety in offshore activities, and major hazards to such installations will be pointed out. Current certification schemes in the North Sea do not consider all these hazards and the scope of certification will be briefly discussed. The remaining part of the paper will concentrate on the certification of offshore structures. Certification aspects of the following novel structures will be addressed: steel and hybrid (steel/concrete) gravity structures; fixed floating structures (tethered or catenary anchored); articulated columns; guyed towers; purpose-built jack-ups; seabed storage tanks; subsea completion systems. Articulated colums are already in use for emergency flaring and for offshore loading and some experience is available. However, they are also very much in focus as surface/seafloor connections for control of subsea completion systems and even as production platforms. One steel gravity structure is under fabrication and the design merits and certification requirements for this type of structures will be reviewed. Tethered platforms as well as guyed towers are two of the most promising concepts for the next generation of deep-water platforms in the range of 150–400 m. A number of design has been subject to precertification reviews and major problem areas will be discussed. A number of simple subsea completion systems is already installed and certification aspects of both wet and dry systems will be presented. For marginal fields in moderate water depths, purpose-built jack-ups may be a solution, particularly for early production, and the use of this type will be reviewed from a certification point of view. For all the concepts mentioned above the emphasis will be on pointing out special features of the design which are outside the scope of existing regulations or certification practice. A number of such problem areas will be discussed in some detail within the fields of hydrodynamic motions and loads, structural design, foundation design and materials engineering.