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

Don Field Decommissioning ProgrammeDON-BP-0013.2 Protection FeaturesThe Don pipeline system has distinct types of protection features installed which areflexiweight mattresses, grout formworks and grout bags. The majority of these are onthe NLGP crossing and at the Don Manifold area, as described in Section 10,Paragraph 3.9.Note: The NLGP crossing will be left in place until the permanent decommissioning ofthe NLGP pipeline and the materials within the Thistle 500m zone will bedeferred until the Thistle is decommissioned.With reference to the areas indicated in Figure 6.3 and quantities listed in Table 6.1, it isproposed that the following features are removed and disposed of onshore [6.3]: All features located within the immediate vicinity of the Don manifold (Area 1) All features located on the 3in Chemical Injection umbilical (Area 2) All features located on the 4in control umbilical (Area 3) All grout bags and mattresses in Areas 4 and 5 Grout bags positioned over the WI Tee location to allow removal of the Tie-in Teestructure (Area 6) Grout bags under the water injection pipeline end, at the spool in the vicinity of theThistle platform (Area 10). Removal will be deferred until the Thistle platformis decommissionedGrout formworks (Areas 4 to 9) located on the Don 8in pipelines will be left in situ andtheir over-trawlability confirmed by trials.PipelinePre-Decommissioning ExistingFeaturesPost-Decommissioning Remaining Insitu FeaturesMats (qty)Bags (qty)Formwork(linear m)Mats (qty)Bags (qty)Formwork(linear m)3in CI Umbilical 2 12 0 0 0 04in Control Umbilical 8 0 0 0 0 08in Oil Pipeline 18 0 109 0 0 1098in WI Pipeline 14 90 192 0 0 192Don Manifold 14 20 0 0 0 0Table 6.1 Protection Features Pre and Post Decommissioning StatusRemoval and Disposal OptionsMay 2011 6-5