§ Mr. Gordon Wilsonasked the Secretary of State for Energy what has been the staffing of the Offshore Supplies Office in each of the years since its inception; where staff are based; and what developments, if any, are expected.
§ Mr. David HowellThe staff in post in the Offshore Supplies Office on 1 April each year were as follows:
leser pipes, pipelines and offshore structures take place; what is the frequency of inspection; and if any patterns of corrosion or metal fatigue have emerged.
§ Mr. GrayOffshore structures for oil and gas in United Kingdom waters are surveyed by an appointed certifying authority each year, with a major survey at least every five years. The extent of the surveys and timing of the major survey 737W depends on a number of factors including the sensitivity of the design to fatigue and the past history of the structures.
So far corrosion has not been a great problem and has been controlled by the use of special coatings and the provision of cathodic protection. Considerable fatigue damage requiring remedial action has been encountered, nearly all in secondary structure and mainly on older installations. Re-analysis of the structures concerned has indicated that none should be at risk of catastrophic collapse and has suggested necessary improvements to be incorporated in future designs.
Pipelines, except for short, " buried infield " pipelines, are inspected externally once a year. Internal corrosion is monitored several times a year. Some corrosion has been found on a few risers and necessary action taken to maintain the required margin of safety. Otherwise minimal indications of corrosion have been found in pipelines. No examples of metal fatigue have been reported.