Inspections offshore

In 1973, a report by the GAO found that the regulator s own standard for the frequency with which to inspect offshore assets in the Gulf of Mexico was rarely being met, 9 despite the increase in the number of inspection staff. It highlighted the need... 

In an offshore oil production platform, a major accident occurred partly because pump seals failed and therefore an antifoaming agent was not delivered to a crude oil separator. The fact that the pump seals were defective should have been picked up during routine inspections, but the inspections were neglected because of production pressures. The failure to carry out the inspections was a latent error. 

Metallurgical and Inspection Requirements for Cast Sacrificial Anodes for Offshore Applications, RP-0387-87, NACE, Houston (1987)... 

Sydberger,T., Evaluation of Inspection Methods for Offshore Pipeline Cathodic Protection Systems , Materials Performance, 22 No. 5, 56 (1983)... 

Isolation - It has been shown that the addition of isolation valves at periodic intervals is not as cost effective as prevention measures such as thickness inspections or tests. However all pipelines should be provided with a means for emergency isolation at it entry or exit from a facility. Offshore facilities may be particularly vulnerable to pipeline incidents as the Piper Alpha disaster has shown. In that accident a contributing factor to the destruction was the backfeed of the contents of the gas pipeline to platform once the topside isolation valve or piping lost its integrity. Further isolation means (i.e., a subsea isolation valve SSIV) were not available. 

Melvc. B.. and Moursund. B. (1994), Acoustic emission testing of glass fibre reinforced pipes on offshore platform. Proc. of the Inspection Structural Composites Conf.. paper no. 13. 

Corrosion in oil and gas production varies from location to location. Corrosion can be classified into one of three general categories of internal corrosion caused by the product fluids and gases, external corrosion caused by exposure to groundwater or seawater, and atmospheric corrosion caused by salt spray and weathering offshore. Of these, internal corrosion is the most costly as internal mitigation methods cannot be easily maintained and inspected. 

Det Norske Veritas (DNV) 1977), Rules for Design, Construction and Inspection of Offshore Structures, Hovik, Norway. 

It would appear that a balance has to be struck between the actual potential value to be gained from an analysis and the level of involvement, time taken, and data required for the analysis. This point is supported by Stacy et al. (2008), who stated, It is important to achieve the correct balance between structural analysis and inspection for the effective structural integrity management of offshore structures in general and it is even more so for ageing installations where there is a greater likelihood of deterioration that needs to be both detected and assessed. ... 

Since there could be hundreds of pieces of equipment on an offshore platform, items should be carefully selected and prioritized to facilitate effective use of limited resources in the management of aging and life extension. The grouping of low-risk items allows one or a small number of pieces of equipment to represent a larger population of equipment for inspection. It should be noted that grouping of high-risk items must be avoided. 

A. Stacy, Technical Policy for KP4 Ageing and Life Extension Inspection Program, 2010-2013, Health and Safety Execntive Hazardons Installations Directorate Offshore Division, November 2010. 

DNV, Risk Based Inspection of Offshore Topsides Static Mechanical Equipment, DNV Recommended Practice Det Norske Veritas DNV-RP-GlOl, October 2010. 

In particular, the structural analysis and inspection should detail the approach to be used to derive structural inspection schemes and provide the foundation for all planned structural inspection activities (e.g., topside structural inspections or ROV surveys for subsea operators). The typical strategy should include structural analysis and assessment to demonstrate integrity analytically and weight control to ensure weight management of offshore structures during their operating life cycles. 

Helge Ryggvik (Chapter 15 in this volume) notes that the number of offshore inspections in the Gulf of Mexico has dropped from the peak of 7,000 in 1994 to approximately 5,000 in 2009. Shortly before the fatal Deepwater Horizon accident, Ry ik had the opportunity to meet with Troy Trosclair, at the time the leader of all offshore safety inspectors in the Gulf of Mexico, whom Ry ik found to be frustrated because he felt he was [at the time] under pressure to reduce the number of inspections on offshore installations (Chapter 15). 

GAO (r985) Offshore Oil and Gas Inspection of Outer Continental Shelf Facilities. GAO/RCED-86-5, Washington, DC (hereinafter, GAO, 1985 Inspection Report). 

Conservative Policy Paper, p. 4. Note, however, that this was not referring to offshore inspections specifically. 

Application of this approach to inspection of offshore installations may not be as straightforward, however. The theoretical argument that transferring the inspections... 

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