Ageing Assets and Life Extension

“The subject of ageing installations is of considerable significance for the offshore industry and one that will remain so with an ever increasing population of ageing structures. This significance is increasingly reflected in the content of current regulations, codes, standards and recommended practices which give recognition to the requirement that specific consideration of the ageing process is required.”

Proceedings of OMAE2008

Within the UK sector of the North Sea, a significant number of platforms are approaching or have exceeded their original design life.

The Health and Safety Executive launched The Aging and Life Extension Inspection Key Programme 4 (KP4) in 2010 to address the key issues associated with the deterioration of plant and the impact on Safety Critical Elements. Duty holders should be able to demonstrate that the deterioration of offshore structures is within acceptable and quantifiable limits through the implementation of an Asset Integrity Management System (AIMS).

Optimus can address both the practical and theoretical aspects of field life extension of existing platforms and vessels:

  • Review of inspection reports of primary, secondary and safety-critical tertiary steelwork
  • Development of strategic structural inspection strategies
  • Identification of repair or replacement scopes
  • Concept, FEED and detail design for the key areas of operational integrity:
    • Accommodation
    • Caissons
    • Lifeboats
  • Use of our advanced engineering capability to undertake structural, hydrodynamic and reliability analyses to justify extension beyond design life.
  • Field life extension studies

Oil Production Platform FLE.

Optimus undertook a study into work required to the topsides of an oil production platform, built in the 1970s the client wished to understand whether they could continue operation until the estimated CoP in 2040. This included a review of each process and utility system and the existing condition of all safety critical steelwork to produce a scope of work for an off-station campaign along with a schedule and cost estimate. Further work was carried out for a 10 year life extension to provide the client with an alternative strategy.

New Field Tie Ins.

Optimus has the multi-disciplinary capability to undertake option assessments for the tie-in of new field developments into existing installations.

Optimus carried out a study to identify and assess options for tie-in of a new field to several nearby installations considering:

  • Field composition
  • Process requirements
  • Existing process capability
  • Brownfield modifications
  • Weight and space restrictions
  • Riser slot availability

The report provided the client with the information required to determine the feasibility of the field and identify options worthy of greater consideration.

Fatigue Assessment.

Optimus are able to carry out fatigue assessments on existing jackets, FPSO’s, FPV’s, flare booms, caissons and risers to risk assessment processes, understanding if an asset component is likely to make to or beyond design life based on known condition and predicted future conditions, and crucially we can make the engineering recommendations for improving remaining life.

FPSO Loadcase Review.

Optimus performed a review of the parameters used in a recent riser design analysis for a UK located FPSO as part of a larger project. The review related to a range of parameters used in the analysis to derive a loadcase matrix consistent with an annual probability of occurrence of between 10-2 and 10-4 in line with ISO 13628-2. The aim was to determine the feasibility of creating such a loadcase matrix and outline the methods that could be used to create a multidimensional map of the best estimate probability of a range of load combinations. Within this map, the 10-4 surface would be located to allow the elimination of load combinations with a combined probability smaller than 10-4.