The existence of new or improved technology such as seismic studies, drilling methods, reservoir treatments (gaslift, water injections, etc.), normally improve the economic of scale for the old reservoir to produce beyond the intended life. The associated facilities life, especially offshore steel structure has to be extended correspondingly. The deterioration conditions of the structures due to corrosions, fatigue cracks, damage members, missing braces, etc. are commonly found on ageing structures. The integrity of these deteriorated structures is always a concern to the operators for the save operations. Most of the cases, it is not economically viable for these ageing platforms to be strengthened to meet the latest codes and standards and sometime the changing environmental conditions. However with existence of the advance computer software, the structural may be analysed beyond its elastic limit for progress collapse behaviour. This approach is nonconventional, but the platform's integrity can be assured for its safe operations with the least strengthening requirements. This paper presents a typical sample of the above approach in assessing the integrity of the offshore structure.
All offshore platforms are designed with a specific design life. In the Southeast Asia region, the design life is between 20 to 30 years. For operators in the Malaysian waters, normally, the lease duration is between 20 to 25 years. The bandover of these old platforms to the new custodian brings a lot of unique problems related to the superstructure (ageing equipment's, vessels and other facilities), the integrity of the substructure is one of the most important factor in the safe operation of the platform. The reserve strength ratio (RSR) is an indication of the platform's integrity and depending on each operator, the minimum RSR value may vary.
