§ Mr. Skeetasked the Secretary of State for Energy what is the present number of oil production platforms constructed in concrete either in the United Kingdom, Norway or Holland which are now operating in the North Sea; how many were 627W constructed at each location; and if he will make a statement about plans for further construction of such platforms in the United Kingdom.
§ Mr. Skeetasked the Secretary of State for Energy of the concrete production platforms located in the British sector of the North Sea, what is the number built in United Kingdom yards and the number built abroad.
§ Dr. J. Dickson MabonThere are now three concrete oil production platforms located in the United Kingdom sector of the North Sea. All were built in Norway. Following the loss of these early orders due to lack of United Kingdom capacity, the Government took steps to ensure that United Kingdom sites were developed to provide a variety of designs favoured by the operators. Three concrete platforms are now under construction in United Kingdom yards and one has just been built in Holland. Clearly, sites are now available for orders and several operators are currently considering both steel and concrete designs and have not yet excluded either.
§ Mr. Skeetasked the Secretary of State for Energy what proportion of all North Sea oil production platforms currently in operation are of concrete or steel construction.
§ Dr. J. Dickson MabonOf the 14 oil production platforms now installed in the United Kingdom sector of the North Sea, 10 are steel jackets, three are concrete gravity structures, and one is a floating production system. Full details are given in Appendix 9 of the Report to Parliament by the Secretary of State for Energy in April 1977.
§ Mr. Skeetasked the Secretary of State for Energy what he anticipates will be the effect of fatigue on North Sea steel platforms; and whether his monitoring of the position has led him to recommend further security arrangement for the protection of the staff accommodated.
§ Dr. John. A. CunninghamNorth Sea structures have been designed using the best knowledge available at the time, fatigue life being estimated from stress cycles calculated from environmental data and being designed to be greater than the estimated working life of the structure.628W Information on environmental data is being collected continuously. This will be taken into account in the four-yearly certification procedures and if necessary vulnerable parts of structures will be reinforced.
In addition, the Department is looking into improved methods of inspection and monitoring of platform integrity. I am advised that it is extremely unlikely that catastrophic failure of a platform will occur due to fatigue.
§ Mr. Skeetasked the Secretary of State for Energy whether the corrosive effect of sea water on North Sea platforms has been greater than anticipated; and whether this fact now warrants further investigation.
§ Dr. John A. CunninghamIn general, the corrosion on North Sea structures has been within expectations, although there have been isolated instances where excessive deterioration has occurred. Unfortunately, corrosion is usually effected by a combination of factors and it is difficult to predict exactly what will occur, although well established practices can reduce the risk.
A close watch is being maintained on these structures and improved techniques for detecting deterioration are in course of development.
§ Mr. Gordon Wilsonasked the Secretary of State for Energy on how many occasions in 1976 he or his oil agencies have engaged consultant engineers to gauge the suitability of platforms or their sites; and how many consultants were employed from firms based predominantly in Scotland and England, respectively.
§ Dr. John A. CunninghamThe Offshore Supplies Office of the Department has retained the services of one eminent firm of consulting engineers since 1975 to oversee the development of the concrete platform sites at Portavadie and Hunterston and to provide advice from time to time on the various designs of platforms for which these sites might be suitable. This firm, although based in England, has an office in Scotland.
Certifying authorities appointed by the Secretary of State for Energy are responsible for ensuring that offshore installations in the United Kingdom sector of the North Sea comply with prescribed 629W standards of design and construction and are suitable for the location involved. These authorities are free to engage consultant engineers as necessary without reference to the Department.