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

Don Field Decommissioning ProgrammeDON-BP-0011 OverviewThis section provides a description of the selected decommissioning options for the DonField subsea facilities and pipelines. These items include: All wellheads and xmas trees The Don manifold Production and water injection pipeline subsea tie-in double spoolpieces andassociated isolation valves at the Don manifold Untrenched sections of umbilicals at the approaches to the Don manifold Flowline and umbilical jumpers between the Don manifold and wellsShortlisted options for the remaining items, ie the pipelines and umbilicals between theDon Field and Thistle, were subject to a comparative assessment for selection of thepreferred option.2 Installations2.1 Wells2.1.1 Don Well CategoriesDon subsea wells are categorised under the Oil & Gas UK (OGUK) Guidelines [7.1] asdetailed in Table 7.1.2.1.2 Methodology and Recommendations for PluggingIn July 2005, OGUK issued revised Guidelines for the Suspension and Abandonment ofWells [7.1]. This provides Operators with a minimum standard for the isolation ofpermeable zones when a well is abandoned or suspended with a view to re-entry or laterabandonment. A revision of this Guidance was issued in 2009, which the Project Teamwill comply with.BP issued the Drilling and Well Operations Policy [7.2] in May 2003. This was to ensurethat wells are designed, drilled, maintained and abandoned to high, minimum acceptableand consistent standards.Both the Drilling and Well Operations Policy and the OGUK Guidelines agree that: All wells shall be left in a condition such that leakage of formation fluid to surface willbe adequately prevented Cement is the prime material for abandonment purposesUsing these guidelines and policy, a suitable plugging strategy is proposed.Selected Removal and Disposal OptionsMay 2011 7-1