Decommissioning Projects
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DNO NORTH SEA
Schooner
Field Type Location Water Depth (m) First Production Contact
Gas 44/26a 71 1996
Dan Wright
UK Decommissioning procurement advisor
dan.wright@dno.no
47 51 21 51 91
Project Summary
Project re-activated in August 2020.

Plan to re-commence P&A activity at Ketch in May 2021.

There is limited impact on the Decommissioning Plan and the completion date remains as in the plan.

The shortlisted tenderers for the heavy lift removal and onshore disposal works have been refreshed and are currently at clarification stage. Reprogramming of these works to coincide with completion of the well abandonment programme is underway.

Subsea scope for pipeline burial / removal, pipeline cuts and recovery of mattresses to be re-issued in Q2 2021, however any activity in this respect is dependent on the outcome of new Ketch licence holder, Wintershall (Round 32).

Currently process ongoing to change operations and maintenance contractor and Duty Holder, however, this is outwith the scope of the Project.

The Schooner SNS gas field is due to be decommissioned along with it's sister field, Ketch starting in September 2018. The project will take approximately 4 years to complete. The fields each have a normally unmanned platform on them, and an export pipeline taking produced gas to the nearby Murdoch platform, which is operated by ConocoPhillips. The Schooner platform has 11 wells drilled from it, and the Ketch has 9 wells. Ketch is in slightly shallower water at 54 metres, but the platforms are of identical design.

The abandonment effort will consist of plugging and abandoning all the platform wells plus one subsea completion (NW Schooner), cleaning and burying pipelines and the removal and disposal of both platform topsides (approx. 1,250 tonnes each) and jackets (approx. 2,000 tonnes each).

The Decommissioning Programmes for both platforms are with BEIS for review and the draft SCAP has been submitted to OGA and a follow up meeting held.

Gate review of well abandonment held in mid September and endorsement gained to advance into concept define.

Decision made to restrict size of Company PMT and to immediately tender for Well Management Company to support PMT and manage large areas of the work. SCAP to be updated accordingly.

Decision made to execute offshore scope sequentially utilising a single jack-up rig. Latest plan shows offshore start at Ketch in early Q4 2019, followed immediately by Schooner.

Discussions ongoing regarding potential reuse of redundant platforms after well abandonment as accommodation support to local wind farm developments.



Contracts Awarded

Title Contractor Name Contractor Primary Contact Date Awarded Contract Band Contact
Rig Hire Valaris Peter Wilson 12-FEB-2021 Large (>£25m)
Peter.wilson@valaris.com
01224 602464
Well Abandonment Management Well Safe Solutions Phil Milton 05-JUN-2019 Medium (£10m-£25m)
phil.milton@wellsafesolutions.com
01224 548400


Challenges

Description Contact Name Telephone Number Email Address
Archive well data has proven to be unreliable, resulting in engineering rework and the need for adaptability in carrying out the offshore operations; dan wright 01224 650938 dan.wright@dno.no
Heavy Lift Removal bids are competitive, however vessel availability windows, aligned to a shifting programme make pricing constraint difficult to manage on an ongoing basis dan wright 01224 650938 dan.wright@dno.no
Reducing offshore attendance to NUI in post-production period whilst remaining aligned to the Safety Case. dan wright 01224 650938 dan.wright@dno.no
Defining best contracting "blend" of Company PMT, Rig Owner, Well Services Providers and Well Management Companies to provide cost and execution certainty. niall anderson 01224 650929 niall.anderson@faroe-petroleum.com
To evaluate potential cost benefit versus "manageability" of running 2 rigs in parallel as opposed to 1 executing work sequentially. niall anderson 01224 650929 niall.anderson@faroe-petroleum.com
Investigating removal of Ketch pipeline as opposed to burial. Taking account of commercial, ongoing liability and environmental considerations in arriving at "best solution" for Project. niall anderson 01224 650929 niall.anderson@dno.no
Potential deferment of tax benefit by reusing platform assets on "non oil and gas" basis. niall anderson 01224 650929 niall.anderson@faroe-petroleum.com
Continuing to examine potential "re use" options for platforms before committing to full removal. niall anderson 01224 650929 niall.anderson@dno.no
BEIS has commented on the Project EIA that all pipeline mattresses where the concrete is bound by polypropylene rope have to be recovered and disposed of in an appropriate manner. This will add significant technical complexity to the Project and will have cost and schedule impacts. niall anderson 01224 650929 niall.anderson@faroe-petroleum.com
Last Updated: 12-MAR-2021 12:13:45


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