The document summarizes OIS's multi-operator well decommissioning campaigns using the Suspended Well Abandonment Tool (SWAT). Some key points: - OIS has successfully abandoned over 100 wells for operators through multi-operator campaigns using SWAT to plug wells in a cost-effective manner. - An upcoming 2015 campaign will use SWAT to abandon 6 subsea wells for Centrica, inserting cement plugs to depths of 2000-3000 feet below the seabed for another operator. - Multi-operator campaigns allow for cost-sharing of vessel mobilization, permitting, and weather downtime across multiple clients.

1. Knowledge Sharing Breakfast;
Decommissioning Efficiency
Aberdeen, 20th May 2015

2. Multi-Operator
Decommissioning Campaigns
and the Suspended Well
Abandonment Tool (SWAT)
By Valerio Percoco

3. Introducing OIS
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• As a leading provider of offshore
and engineering services, OIS
understands that decommissioning
is an expense and not an
investment and believes that cost
minimisation and “Fit for Purpose”
need to be the drivers for a
successful collaboration with its
clients.
• We love our planet and intend to
assist in restoring the environment
to an unspoilt and enjoyable sea;
during this time OIS has had no
reportable environmental incidents
or a single offshore lost time
incident.

4. A Quick Overview
• The SWAT system is an integrated tool deployed from a Light CSV and can perform
all the P&A tasks for a safe and responsible operation on Cat 2 Subsea and* Mud‐
line wells.
• In 2013 the campaign consisted of six subsea wells which were successfully
abandoned for three operators in Central North Sea.
• In March 2014 OIS completed its first well abandonment campaign in Norway.
• Summer 2015 will consist of multiple wells in the North Sea being abandoned on
behalf of Centrica. The initial campaign includes six subsea wells in the Central
North Sea, in categories 2.1 and 2.2, which will be abandoned using a driverless,
vessel‐based approach.
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5. The Track Record
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OIS has successfully abandoned 118 category 1 and
2 wells since 1996 during 17 UKCS multi‐operator
campaigns by employing a turnkey, vessel‐based
solution.
• 12 wells were Category 1
• 50 wells were Category 2.1
• 53 wells were Category 2.2
• 3 wells were Category 2.3

6. Well Abandonment Campaign
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OIS provided integrated project
management throughout the onshore and
offshore operations, including:
Sourcing and reviewing well‐specific data to
identify assets suitable for vessel‐based
abandonment
Performing initial well reviews
Appointing and managing all subcontractors
Supporting completion of environmental
data related to abandonment operations,
including: OPEP (Oil Pollution Emergency
Plan), PON 5 (Application to Abandon a
Well), PON 15f (Permit to use/discharge
chemicals during well abandonment) and
Marine Coastal Access Act License

7. UK Oil & Gas Well Categorisation Requirements
• Under UK Oil & Gas guidelines, wells requiring insertion of shallow cement plugs across
the well bore and annuli are classed as category 2 with the following sub‐categories in
place:
• Category 2.1 – One casing string.
• Category 2.2 ‐ Two casing strings.
• Category 2.3 – Three casing strings.
• In order to be classed as category 2, wells must have deep set permanent cement plugs
in place. If they do not then they are not suitable for intervention using the OIS
systems.
• Upon insertion of shallow cement plugs (UK O&G requirement – 100ft of good cement),
a well will be classified as category 1.
• In order to be abandoned in line with UK Oil & Gas requirements, category 1 wells not
only require removal of well head and casing (UK O&G requirement – casing to be cut
10ft below mudline) but also any permanent guide base, temporary guide base or
associated subsea structure.
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8. 2015 Multi- Operator Campaign
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In July 2015 OIS will be conducting its 17th Multi‐Operating Campaign in the Central
North Sea.
Work Scope:
• OIS will design, engineer and manage the
abandonment of 6 x Category 2 subsea wells in
the Central North Sea for Centrica Energy.
• Water depths range from 300 to 420ft.
• OIS will contract the Island Valiant to perform
the intervention operations and utilise the
Market leading, Claxton owned SWAT tool to
perforate, recover drilling fluids, install
additional barriers and pressure test the new
barriers. Following the intervention operations
the vessel will begin the abrasive severance
and recovery of each of the wellheads.
Operations are likely to take 28days in total.

9. 2015 Multi-Operator Campaign
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Innovative Solutions
A further operator has 2 suspended
category 2 subsea wells however these
wells require an additional barrier to be
positioned at 2000 to 3000ft below the
seabed. OIS and our sister company
Claxton Engineering have developed the
SWAT capability to enable positioning of
the new barriers far deeper than has
been achieved to date.

10. Wellintel
In order to have the opportunity to take part to a Multi Operator campaign, permits
need to be submitted to the authorities timely.
• OPEP (Oil Pollution Emergency Plan) – consent can take up to 60 days from
submittal.
• PON 5 (Application to Abandon a Well) – consent can take up to 21 days.
• PON 15f (Permit to use/discharge chemicals during well abandonment) – consent
can take up to 28 days.
• Marine Coastal Access Act License ‐ new applications can take several weeks.
Early engagement is vital with the supply chain as preparation with the permits will
enable clients to jump onto an early campaign and benefit the cost saving.
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11. Costs
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Weather Risks
The risk of waiting on weather is
mitigated by having a large number of
wells/ customers. This would mean
sharing of the costs associated with
such periods
Total Transit
The higher the number of participating
wells, the lower the cost for each
operator.
Total Transit = 6 days.
4 participating wells = 1.5 days Transit
allocated per well.

12. Multi- Operator vs Standalone
Multi – Operator Campaign Stand Alone Campaign
(Low Number of Wells)
Commercially Efficient YES NO
Detailed Planning YES YES
Consistent Equipment YES YES
Shared Risk of WoW YES NO
Shared Cost YES NO
Shared
Transit/Mob/Demob
YES NO
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13. SWAT
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• The SWAT System is designed to
permit perforation, circulation
and cementation of multiple
casing annuli.
• Designed for deployment from
the back deck or ideally through
the moon pool of a light CSV. The
tool is landed on the 9 5/8” casing
hanger and controlled from the
surface through an umbilical.
• 100% redundancy as one
complete spare system is carried
on deck.
• The system received the Queen’s
Award for Engineering Innovation
and Petroleum Institute Platinum
Award.

14. SWAT Tool- Technical Snap Shots
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Recover Trash Cap Position Guide Cone

15. SWAT Tool – Technical Snap Shot
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Lowering of Guns SWAT Running in Hole

16. SWAT Tool – Technical Snap Shots
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Packers Inflated Pressure Tests between SWAT Packers

17. SWAT Tool – Technical Snap Shots
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Pressure Test to confirm lower packer
functionality and integrity of well
Firing 3‐3/8 inch gun perforating 9 ‐5/8in
casing

18. SWAT Tool – Technical Snap Shots
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F.I.T on 13‐3/8in shoe Firing upper 2 inch guns perforating
9.5/8in casing

19. SWAT Tool – Technical Snap Shot
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Circulate path bore and A annulus –
Clean up annulus
1st stage cement job reversed
circulation in A annulus

20. SWAT Tool – Technical Snap Shots
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Pressure test A annulus cement plug Firing lower 5.5 inch guns
perforating 9.5/8inch and 13.3/8in
casing

21. SWAT Tool – Technical Snap Shot
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F.I.T 20 inch shoe
Fire upper 3.3/8inc guns, perforate
9.5/8 inch and 13.8 inch casing

22. SWAT Tool – Technical Snap Shots
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Circulate path bore and B annulus ‐
Clean up annulus
2nd stage cement job –
conventionally circulate into bore
and B annulus (Both annuli and
bore are filled with cement)

23. SWAT Tool – Technical Snap Shoot
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Releasing of lower guns Pressure test on new plug