Don Field Decommissioning Programme (pdf, 7.8MB) null - BP

Don Field Decommissioning ProgrammeDON-BP-0011 IntroductionThis section lists the type and quantity of materials for the items to be decommissioned.This material inventory does not include the following items, which will be deferred untilthe Thistle Installation is decommissioned: The 30in caisson at the Thistle Installation, containing an 8in production riser (PL598),8in water injection riser (PL599), two 7in and one 2 3/4in conduits Don topsides equipment and piping on Thistle (eg Emergency Shutdown Valves(ESDVs), pigging facilities, control and chemical injection systems) The pipebridge leading from the caisson Pipeline and umbilical systems leading from the pipebridge to the platform 500m zoneNote: Pipeline inventories do not include stabilisation items at the Northern Leg GasPipeline (NLGP) crossings. These are discussed and itemised separately inParagraph 3.3.Refer to the Don Pipeline System Decommissioning Technical Report [5.1], produced byLloyd’s Register, for additional pipeline and umbilical information.2 Subsea Equipment2.1 WellsA planning estimate of the material to be recovered from the Don Field wells is listed inTable 5.1. In addition, there is a limited quantity of contaminated fluid contained in thewell annuli.Item Material Weight in Air (tonnes)Subsea xmas trees and guide bases Steel 252.0Tubing Steel 645.0Casings Steel 220.0Total Weight 1117.0Table 5.1 Don Wells Material Inventory2.2 Don ManifoldThe Don manifold was designed so that it may be disconnected and retrieved using aMobile Offshore Drilling Unit (MODU) or similar. The manifold is clamped to two pileshammered into the seabed to a depth of approximately 10m. The material inventory islisted in Table 5.2.Inventory of MaterialsMay 2011 5-1