Читать книгу Underwater Inspection and Repair for Offshore Structures - Gerhard Ersdal - Страница 29

The SIM process is often defined as; the collection of necessary information about the structure, its condition, its loadings and its environment to enable sufficient understanding of the performance of the structure to ensure that loading limits are not exceeded and that safe operation is assured.

The most recent SIM standards are based on a major hazard approach to the integrity management of structures and other assets, as exemplified in API RP 2FSIM (API 2019a), API RP 2MIM (API 2019b), ISO 19902 (ISO 2007), ISO 19901‐9 (ISO 2019a) and NORSOK N‐005 (Standard Norge 2017b), which are further discussed in this section. This approach is based on methodology that seeks to understand the hazards to which the structure is exposed, the possible consequences of these and how these should be mitigated. This includes ensuring that suitable safety measures (often called barriers) to protect against the hazards turning into unfavourable consequences are established and maintained throughout the life of the facility. A key element of the major hazard and barrier management regimes is the prioritisation of activities, including inspection and repair for the important safety systems and barriers. Several standards and reports have been published on the principles of SIM, such as HSE RR684 (HSE 2009). These identify a number of key processes which are considered good practice in SIM, together with an appropriate management scheme and documentation.

Inspection is a key element of the surveillance activities and will include in‐service inspection of the structure to identify deterioration, degradation and damage. The process of identifying such anomalies will often be the most extensive and costly part of the surveillance activity (both strategy and programme).

Repair is the necessary mitigation activities in order to retain the safety of the structure if inspection has revealed anomalies of significant concern. The repair method of choice is typically based on output from a structural evaluation or assessment.

Several standards have recently been developed to guide the operators of floating facilities in their integrity management including inspection, such as ISO 19904‐1 section 18 (ISO 2006) and NORSOK N‐005 appendices F, G, H and I (Standard Norge 2017b). Further, a document prepared by Oil & Gas UK (O&GUK 2014) on the management of ageing and life extension for floating production installations provides detailed information relevant for inspection of ageing floating installations. Inspection features as a key control measure in managing the ageing mechanisms such as fatigue and corrosion, although little detail is given on the actual recommended inspection tools and technique. The main topics in the Oil & Gas UK (O&GUK 2014) are the integrity management and inspection of:

 hull (structural and watertight integrity);

 marine system, including ballast system, control system, cargo system, inert gas system and marine utilities (pumps, generators, etc.);

 station‐keeping systems (mooring and DP).

NORSOK N‐005 (Standard Norge 2017b) builds upon this Oil & Gas UK (O&GUK 2014) report, breaks down the non‐structural systems into a number of components and identifies whether inspection based on class rules or based on generally accepted maintenance standards such as NORSOK Z‐008 (Standard Norge 2011) is appropriate.

Standards and recommended practices for SIM are given in API RP‐2SIM (API 2014b), API RP‐2FSIM (API 2019a), API RP‐2MIM (API 2019b), ISO 19902 (ISO 2007), ISO 19901‐9 (ISO 2019a), NORSOK N‐005 (Standard Norge 2017b) and HSG65 (HSE 2013). These do to a large extent include the SIM process described above.