1. What’s the future of decommissioning globally?
And why Aberdeen based Engineers should care…
In this presentation I’m looking to show that there is a real opportunity… an opportunity for structural engs like you and I, to take our decommissioning experience world wide. I will focus on offshore structural aspects in this presentation.

2. Introduction – what are the options?
Recycle it!
Ekofisk topside 2004
98% rate of recycling by weight
Create something (re-use)?
Morris Architects vision
Turn an abandoned oil rig into a residential resort
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

3. Currently existing global “alternative use”
Rigs to Reef (warmer climates)
Rigs-to-Reefs (RTR) is the practice of converting decommissioned offshore oil and petroleum platforms into artificial reefs. Such biotic reefs have been created from oil rigs in the United States, Brunei and Malaysia.
Tow and Place: Sever the structure from the sea floor and tow it to a state-approved location.
Partial Removal: Remove the top portion of the submerged platform and either place it on the sea floor or tow it to another site. Partial removal can result in a loss of the shell mound community and fish that live in the top section but the rest (the majority) of the habitat remains intact.
Toppling: Toppling (like the Piper Alpha) involves uses explosives to sever the base of the structure below the mud line to topple the structure over. Toppling eliminates shallow and mid-ocean habitats, however, these areas are quickly occupied by other aqueous lifeforms.

4. Decommissioning Strategy
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

5. OGUK Work Breakdown Structure (WBS) Source OGUK 2013
The components drawn vertically represent those where expenditure & activity span the entire decommissioning process
This presentation will focus on the structural aspects.

6. How much money is going to be spent decommissioning offshore oil and gas structures in the North Sea?
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

7. UKCS DAR Cost Estimating Source OGUK 2013
Forecast from 2013 to 2022
The proportion of total estimated decommissioning expenditure from 2013 to 2022 for each component of the WBS is shown.
In line with the past two decommissioning surveys, wells plugging and abandonment represents the largest category for expenditure at 43 per cent (£4.5 billion) of the total expenditure. Topside removal accounts for 13 per cent (over £1.3 billion) of the forecast expenditure and a further 11 per cent (nearly £1.2 billion) is attributed to facility running and owners’ costs, the majority of
which are operational costs associated with running a manned facility while decommissioning takes place.
Decom business worth in the UK £10.4 billion

8. What happens when the “licence to drill” is coming to an end?
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

9. Decision making matrix
Can the life of the installation be extended?
Re-use
Existing
Structure
Cessation of production application: No
Yes
Licence Extension? No
Subsea tie back / Plug wells
Technical
Safety
Environmental
Societal
Economic
Platform
Redundant
Yes
eg: Residential resort, Prison, Wind farm…
Permission to extend licence
Comparative Assessment
Simplified decom decision matrix.
OSPAR 98/3 prevents RtoR in the north atlantic waters. Been done in Gulf of mexico. Also more likely to be done to a piece medium removed jkt which will . ie. Dropping chunks on the seabed rather than “single lift” removed structure.
Derogation vs complete removal
eg: Rigs to Reef (GOM),
NS = too cold
Single Lift /
Piece small / medium removal
Recycling value

10. Offshore Fixed Structures
Oil & Gas
Offshore Fixed Structures
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

11. Oil & Gas Offshore Fixed Steel Structure Timeline
“Out of sight of land”
1947
Block 32
First Fixed Steel Piled Jacket
1967
West Sole A
First Planned UK Platform
Decommissioned
1993
Forbes AW
(Removal to shore)
1947, Kerr-Mcgee, in USA, Ship Shoal block 32, off coast of Louisiana was first out of sight of land offshore fixed platform.
Although commercial extraction of oil on the shores of the north sea dates back to 1851, it wasn’t until 1967 saw the first north-sea fixed piled jacket structure.
The first planned platform to be decom was Crawford Floating Production, Facility (FPF)Removal to shore1991Catenary Anchor Leg Mooring (CALM) BuoyRemoval to shore1991 Subsea Facilities Removal to shore1991
Most recent in 2014 approved planned decom: Murchison Large Steel Platform Topsides and jacket to top of footings to be removed to shore for recycling/disposal. Footings to remain in situ 2014 (Will explain why later on) and Export pipeline decommissioned in situ with remedial rock placement. Infield Flowlines to be removed for recycling/disposal.
There are 556 steel piled structures across the region, 52 decommissioned, OSPAR convention govern decom of offshore north sea structures since feb 1999: structures to be removed for disposal on land. Exceptions: concrete gravity structures & jackets installed before 1999 exceeding 10k te weight.
Planned Platform
Decommissioning
2014
Murchison

12. Lets put the jacket size into perspective…
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

13. Examples of Steel Piled Jacket Categories in the north Sea Region
Barge Launch jackets weigh 5k to 25k te.
Self floater >12k te, 2 large up to 10 m diameter legs for buoyancy during installation. Upended through controlled flooding.
Lift installed structures <10k te.
Shallow water jackets < 2k te.
First generation jackets weren’t designed to be reverse installed.
When removing these jackets, there is marine growth, the bottles (piles, piles sleeves and grout) any flooded members all to be considered as additional lift weight. Buoyancy does support the structure during removal, however, when the jacket is placed horizontal on the barge, the plan bracing members adjacent to the piles clusters are subject to a compression load they may not have been designed for.
Modern jackets are now designed with removal engineered into the design. Additional strengthening is engineering in to enable decommissioning.
Why do we have to account for the piles? –
according to OSPAR (Oslo and Paris Conventions) they are part of the structure and have to be removed and DECC (Department of Energy & Climate Change) suggest to a level below the seabed whereby they are unlikely to be exposed (generally accepted as ~ 10ft or 3m to 5m)
What about derogation you say?..will we get to that later.
The designed integral buoyancy for installation could support removal if it was proved to be operational, but how likely is that??

14. So what is derogation?
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

15. UKCS DAR – Summary of Requirements (Facilities)
Derogation possible – if the jacket weight is greater than 10k te and the water depth sufficient.

16. Derogation – Murchison 2014
Disc 1975
Drilling 1980
Topside weight 24,584te
Jacket weight 24,640te
Water depth 156m
The planned decom report for the Murchison platform has recently been approved in 2014.
CNR website notes:
Cessation of production took place according to plan on 28 February 2014.
the decommissioning of Murchison has now begun with the engineering-down and cleaning of the platform and the campaign to plug and abandon the oil wells in the Murchison field well underway.
Topsides via reverse installation, returned to offshore for re-use or recycling.
The derogation case has been granted for the jacket and 44m will remain above the seabed.
Jacket Group Gross dry weight (tonnes)
Jacket structure + piles + grout + marine growth + flooded members
27,584
Jacket structure + piles + grout + marine growth + drained flooded members
26,131
Grout and piles 11,278
Jacket + marine growth from surface down to -112m (top of footings)
14,853
Estimated weight of marine growth 2,394
Existing Jackets were not designed with removal / decommissioning

17. Offshore lift…
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

18. Versabar (VB10,000) Single Lift Removal Methodologies - Topsides
Single topsides lifts
Existing decommissioning vessel - VB 10,000
A fully automated DP3 dynamic positioning system, consisting of four 1,000-HP retractable thrusters in each of the two barges, eliminates anchors and mooring lines. The VB 10,000 can operate in waters of any depth, enter and leave lift sites at any hour without the aid of tugs, and hold station with a high degree of accuracy measured.
Versabar’s VB 10,000 performs a float over lift to remove a
2,450-ton topside from its jacket.
Versa Truss
ADAPTABILITY
The Versatruss heavy lift system can be adapted to virtually any topside lift package, and the lift capacity can be increased by increasing the size of the components.
Versatruss system employs 2 barges with standard lifting apparatus, one either side of the platform.
Claiming theoretical installation of integrated topsides up to 40k te. Its suitability for jacket removal has been unproven as is its suitability for the north sea environment.
Existing!! There are a few others in concept / design / construction.
These have only been used in the GoM, don’t think these have been used elsewhere yet. Versa bar is more suited to recovery of damaged platforms I think.

19. Single Lift Removal Methodologies - Subsea
Buoyancy Removal Method BRM)
The BRM is a jacket re-floating method developed and patented by Aker Kvaerner. This method has been used previously for the transport of the Frigg DP2 jacket (transportation weight 11,600Te), in It is understood that the Frigg buoyancy tank assemblies still exist, and have the capacity to lift up to 18,000Te. The buoyancy removal methods require additional offshore activities which introduces additional risks.

20. Heavy Lift Methodologies – Topsides and Subsea
Thialf has two cranes with a combined maximum lifting capacity of 14,200 metric tons, making it the largest crane vessel in the world.[4] but has lower height lifting capabilities than its competitor Saipem 7000 (which has lifting capability of 14,000 tonnes at 42 meters while the Thialf can lift 14,200 tonnes at 31.2 meters).

21. Single Lift Methodology – Topsides and Subsea
Pieter Schelte.
Future Methodologies
New build decommissioning vessel - Peiter Schelte (PS)
The PS will have a topsides lift capacity of 48,000 t and a jacket lift capacity of 25,000 t.
The vessel is able to single lift remove both the jacket and the topsides and carry them on deck.
Accommodation is for 571 persons.
Double-joint factory with 5 line-up stations and 2 stations for combined external and internal welding; Main firing line with 6 welding stations for double points, 1 NDT station and 6 coating stations.
Delivery Date is the second half of Delivery of the completed topsides lift and pipelay vessel is expected in the second half of 2014, ready for offshore operations early The jacket lift system will follow later. In November 2013 Allseas announced plans to build a second single-lift vessel larger than Pieter Schelte, to be delivered in It is intended for installation and removal of the very largest existing platforms.
Its currently in Korea and is due to Holland in 2015 for installation of the lifting systems and final fit out. It’s running late.
Its real and its happening right on our doorstep…it has been contracted by Shell to remove Brent D, B & A topsides and Brent A jacket. Starting Show me a struccy that isn’t excited by this and I’ll show you a sparky in disguise. Not without issues though, the jacket lift system is being redesigned, cos they are finding that few if any jackets can withstand the lifting and rotating, especially when considering bottles and piles.

22. How do we detach all this
from the seabed?
What about re-use for the same purpose in a different location ( Hutton TLP topsides modules)

23. Cutting Technologies
Internal Cutting Manipulator (water jet) V Sub Bottom Cutter (Diamond wire)
1 – Vertically deploy
2 – Directly connect
3 – dredging soil
4 – pivot arm
5 – cutting leG / pile
6 – CRANE REMOVAL
The internal cutter using abrasive water jetting can cut from 42in – 72 in diameter piles or jacket legs.
The sub bottom cutter can cut piles below the sea bed using a pivot arm action with diamond wire.

24. CUTTING OF JACKET AND PILES
Cutting Techniques
Diamond Wire Cutting Machine (DWMC)
This technique has been developed as a cutting solution for structures where a level of stability is required in preparation for their subsequent removal.
CUTTING OF JACKET AND PILES

25. Cutting Techniques
Hydraulic Shears
Title of Presentation

26. The world asks Aberdeen
There are more than 5,000 oil & gas structures offshore, world-wide. At the end of their operational life, these structures will require decommissioning.
The decommissioning process presents a number of critical challenges to operators in terms of engineering capability, safety and – significantly – costs. In addition to the national regulatory processes that set out requirements for decommissioning, regional and international (global) processes and requirements have been developed.
BG India (logo) came to abz for decom expertise to support the creation of industry leading regulations in India. The regulatory landscape for decommissioning continues to evolve – providing the mechanism for advances in the region. Operators are collaborating with regulators to progress local decommissioning guidelines.

27. From Forbes AW 1993 to Murchison 2014
Conclusion
Aberdeen Decommissioning Experience:
From Forbes AW 1993 to Murchison 2014
We believe with the Potential in this room:
Your Expertise + Attitude
= Opportunity for us Structural Engineers?
Aberdeen as THE hub of future global decommissioning?
In conclusion, ive tried to give an overview of decom, and we’ve looked at the Murchison case study demonstrating the experience we have here in abz…and I hope this provokes some thoughts /feedback from you… I hope this presentation might provoke conversation
The potential in this room… your expertise – after all, the majority of platforms successfully decom having occurred with Aberdeen based expertise…. Means that this is an opportunity for structural engineers like you and I
Because surely there’s potential for Aberdeen to be THE hub of future global decommissioning.
Some of you are probably thinking, Surely the GOM is the right place for decommissioning, not here in little old Aberdeen, after all, we are just a little place and it’s too expensive here plus our regulatory system is too strict? and then you go on to counter these points with your evidence /ideas?

28. Charity www.energyfuturesne.com

29. Charity – Supporters www.energyfuturesne.com