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

Don Field Decommissioning ProgrammeDON-BP-0011 OverviewThe objective of these Decommissioning Programmes is to plan and execute thedecommissioning of the Don Field in a safe, professional and environmentallyresponsible manner with an outcome acceptable to the United Kingdom Authorities, theSection 29 Notice Holders and other interested parties.The Don Field has reached the end of its economic life, having produced a total of15.8 Million Stock Tank Barrels (MMSTB), with COP [2.1] on 15th January 2005. TheseDecommissioning Programmes outline the Section 29 Notice Holders’ plans for thedecommissioning of the following: Don Field subsea equipment (ie Don manifold, wellheads – including xmas trees) Flowlines, chemical injection and control umbilical jumpers between the wells and theDon manifold Pipelines, umbilicals, and protection and stabilisation features between the Donmanifold and the Thistle topsidesWith a view to decommissioning the above, the Decommissioning Programmesrecommend that: Wells are plugged and abandoned, and the wellheads and manifold removed(manifold piles will have a clearance to 3m below the existing seabed level) All flowlines, associated flexiweight mattresses, chemical injection and controlumbilical jumpers between the wells and the Don manifold are removed Pipelines and umbilicals between the Don manifold and the Thistle Installation 500mzone are decommissioned in situ Flexiweight mattresses and associated uncovered pipe along the pipelinesare removed Grout formwork will remain in situ subject to successful over trawl trials Pipeline and umbilical Northern Leg Gas Pipeline (NLGP) crossings will be deferreduntil the NLGP is decommissioned Sections of the pipeline within the 500 metre zone, the pipebridge, risers andassociated topsides equipment at Thistle will be deferred until the Thistle Installationis decommissioned Drilling cuttings will be left undisturbedThis Decommissioning Programmes are fully consistent with the Department of Energyand Climate Change (DECC) Guidelines [2.6], and require no derogation from therequirements of OSPAR Decision 98/3 [2.2].Executive SummaryMay 2011 2-1