4d_5_Clair

Clair Project commenced with an extended Review. It was problematical to establish the extent and structure of the find and how the find could be exploited. This went on untill 1997 when Development was approved. The Partners had had a problem to agree a design basis for the Platform which showed promise and one of the Partners withdrew removing some of the dissension. This was about the same time that Woods in Aberdeen had taken control of Mustang Engineering in Houston. There participation in the design basis gave access to a recent design of platform that Mustang had completed on a GOM Design Basis. Replicating this gave economies to the proposed project and the now partners were able to agree a basis for Clair Development.The initial Basis of Design can be described as Conventional North Sea Orientated the elected, in 2002 Mustang commenced a FEED with design on a GOM basis. A major difference between these two concerns the approach to an Explosion. In the first there was containment in the GOM design the approach is spaciousness and non containment allowing forces to spill out from the platform into free air. The safe style areas (accommodation, lifeboats, egress) are placed away from hazards. Areas with some element of hazard (Power Generation) are placed between Hazardous and Safe Areas. Another factor is that this approach allows a structure which is tree like and the equipment Modules or Packages to sit like fruit on the branches. This structure is somewhat lighter than the Box Style used for Magnus. The open style basis of design would not find favour in some North Sea Developments. The Norwegian Sector would have a problem with occupancy i.e. men working on Equipment exposed to the elements for any period of time. At the projected time of installation the availability to lift a complete Topsides as a one piece Module of 10,000 - 12,000 te was slated to be available (see notes on Slewing Crane Lifting). By containing Clair Topside weight all of these factors discussed added to the viability. Clair FEED followed these principals. The size and weight of the Topsides allowed the Jacket to be a simple 4 legged structure. To achieve the weight the Drilling Facilities were designed as lift on Modules ( DM, Drilling Module and DSM, Drilling Support Module) after the Topsides were installed. Another weight reduction was the Design of the Living Accommodation as a one piece lift on Module to hang on the end to counterbalance the weight of the Process areas on the other end. (Norway at that time had two Accommodation Module Suppliers, one specialised using steel, the other Aluminium (Lerviek Sveis). For this Topsides weight reduction was a major interest and thus the Aluminium option was chosen). At Load out (on wheels by Mammoett) the Topsides wayed 11,000 te. The Diagam below shows the Projected Topsides. Being intially designed in Houston elements followed practice there eg Solar GT,s for Power, Gulf Suppliers for Equipment etc. It did have some sorting out of Euro Norms, BP Standards and Codes of Practice. In the following year the design migrated to the UK for finalisation. First Oil for the Platform was in 2005. Clair has been followed by Clair Ridge. This follows similar elements of design.but the equipment required was far more extensive than Clair and required 2 platforms. One is 4 Legged for Accomodation and Power Generation the other multi legged for Drilling and Production. The two platforms are arranged so that the elements are in the same sequence of layout as Clair. The lifts for this Platform used CLV Thialf and were again targetted at 11,000 te