International competition, and to some extent the CRINE initiative, have stimulated oil and gas operators to minimise production costs wherever possible. Underwater inspection, repair and maintenance (DRM) of the platform jacket consumes a major proportion of the overall maintenance budget and consequently any reduction in this area is likely to have a significant impact on overall costs.
All offshore jackets are inspected regularly to ensure structural integrity and satisfy the strict statutory requirements. Technical advances have been achieved in recent years, particularly in ROV capability, which have led to a general reduction in highly expensive diver time. However, it is widely recognised within the industry that inspection costs could be further reduced by combining such advances with a much more rigorous planning philosophy, the aim being to reduce the total amount of inspection activity whilst maintaining or improving the effectiveness of the work carried out.
Quest Consulting Ltd and Aberdeen University are working jointly on a Teaching Company Scheme, part funded by the Government, to develop methods and tools for targeting the inspection of offshore structures at areas of greatest criticality on a sound scientific basis. This paper presents the results of ongoing research and proposes that planned inspection should include a refined risk assessment to rank components and define the most appropriate inspection methods and optimum inspection intervals for a given structure. This will result in the most cost effective approach to underwater inspection being implemented.