Project Profile
Value: US$150 million
Location: Block 20/2a in the Central North Sea, UK
Start-up Year: Q4 2011
Water Depth: 113m
The Blackbird discovery is located in block 20/2a in the Central North Sea and is a potential tie-back to the existing Ettrick infrastructure. Located 4 miles (6 kilometres) south of the Ettrick field on Block 20/2a, in a water depth of 367 feet (112 metres), is a field named Blackbird. Nexen serves as the operator and holds an 90.61% working interest; and Atlantic Petroleum holds 9.39%. The 20/2a-8 well, drilled by the semisub GSF Arctic IV, encountering 111 feet (34 metres) of net pay in multiple zones, was drill-stem tested and flowed at an average rate of 3,800 bopd through a 34/6 inch choke.
In 2010, Nexen appraised the field by the 20/2a-9 well, which reached a total measured depth of 12,000 feet (366 metres), targeting a high quality Upper Jurassic oil discovery. It encountered approximately 330 vertical feet (101 metres) of gross oil-bearing section. Preliminary wireline log analysis indicates 75 feet (23 metres) total thickness of good quality, oil-bearing reservoir sands. Blackbird will be developed as a subsea tie-back to the nearby Ettrick floating production, storage and offloading vessel.
Decommissioning Schedule
• Buoy and moorings removal in 2017-18
• Well plugging and abandonment in 2018-19
• Subsea infrastructure removal in 2019-2020
**Blackbird field decommissioning programme (approved by BEIS and implemented in parallel with Ettrick field decommissioning): phase 1: Subsea scope 1, comprising DTB, risers, MWA, moorings, to be completed by end-2017. Phase 2: wells plug and abandonment (P&A) to be completed within window of Q2 2018 to Q4 2019, although expected execution is by end-Q1 2019. Phase 3 Subsea scope 2, comprising manifolds, flowlines, overtrawl trials, to be completed within window of Q1 2018 to Q4 2020, although expected execution is by end-Q3 2020. Phase 4: post-decommissioning survey to be completed within window Q2 2019 to Q4 2020. Projected costs disclosed to UK Department of Business and Energy (BEIS) but not yet publicly released.**DF, 02/01/2018
Operators:
Nexen: Operator with 90.6% interest
Atlantic Petroleum (UK) Limited: 9.4% interest
Contractors:
First Subsea: FEED contract
Subsea 7: Construction and installation of pipelines EPC
Transocean: Drilling contractor with semi-submersible Arctic IV
Xodus Group: Contract with Nexen Petroleum U.K. Limited to provide Front End Engineering and Design (FEED) services in support of the decommissioning of the Ettrick and Blackbird fields in the central North Sea. The workscope will assess the best practice decommissioning methods for the main items of field architecture, including the structures, flowlines, umbilicals and risers. The work involves developing the decommissioning methodology for the field taking account of current industry best practice to ensure a technically robust decommissioning solution is developed.