mm subsea case study pack

8/17/2019 MM Subsea Case Study Pack

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CASE STUDY

www.miragemachines.com

Subsea

Case Studies


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CASE STUDY

www.miragemachines.com

Contents

• Subsea Window Machining

• Subsea Pipe Cutting

• Weld Seam Removal

• Platform Leg Crack Termination

• Tidal Fin Removal

• Seam Weld and Doubler Plate Removal

• CIMV Removal & Torque Tool Development

• Injection Point in Trace Heated Supply Line

• About Mirage Machines


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www.miragemachines.comEmail [email protected]

PORTABLE PERFORMANCE

05.02.16

Subsea WindowMachining Case Study


A 26-1/2” conductor required a 1.3 x 0.45m windowmachining with 50mm radii 9m from the sea bed for a

mud dump vent clamp to be fitted.

Location: Apache North Sea – Forties Delta – 115m

water depth.

Requirements

Cold cutting was specified due to the 26-1/2”

conductor housing 13-3/8” casing and a power line

that could not be damaged during cutting.

The four corners were pilot drilled and then the 4 off100mm diameter holes were trepanned at fixed

centres, with hydraulic valves acting as datum point

stops. The gantry system was then used to mill

between the corners to produce the window. The cut

out portion of the conductor was retained by cross

member clamps with drilled and tapped holes in the

conductor.

Drilling and trepanning took 45 minutes per hole,

machining top, bottom and sides through conductor

thickness.

Equipment used

• Mirage gantry GM2000 and milling rail MR1500.

• Used with a chain pipe clamp.

Solution

• Machining completed within 2 days.

• Operation time kept to a minimum using

hydraulic stops and auto feeds on the main axis.

.

Outcomes

Workshop trial.

Milling rail mounted onto the Gantry system

with large hand wheel for the diver to control

the in feed. The auto stop hydraulic valves

controlled the size of the window and

spindle positioning.

Click to watch the

YouTube video

https://www.youtube.com/watch?v=r6acVR6Zgo4https://www.youtube.com/watch?v=r6acVR6Zgo4


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05.02.16

Subsea PipeCutting

Case Study


• To remove a 512 metre length of Super

Duplex pipe from the sea bed, at a depth of

50 metres. Pipe specification 12” diameter

with a 1” wall thickness.• Location: Saudi Arabia.

Requirements

• The Mirage MDWS used with a 3 circuit

hydraulic controller. The diamond wire

travelled at 1200 metres per minute at a

feed rate set at 8mm per minute.

Solution

• 22 cuts made within 72 hours.

• Pipe sections around 23m long raised to deck.

• With the pipeline removed the customer was

able to construct a new pipeline.

Outcomes

The first two pipe sections recovered from the sea bed.

The MDWS being lowered into the sea.

Click to watch the

Diamond Wire Saw

animation on YouTube

https://www.youtube.com/watch?v=h5KNAyN3dHAhttps://www.youtube.com/watch?v=h5KNAyN3dHA


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05.02.16

Weld SeamRemoval

Case Study


Removal of a longitudinal weld seam to allow fitting

of a ‘Morgrip’ connector.

Location: Apache North Sea, Forties Delta.

Requirements

• Use of the Mirage MR1500SS milling rail

• Workshop trials carried out in advance.

Solution

Successful machining allowed fitting of the

‘Morgrip’ mechanical connector.

.

Outcome

Workshop trial.

Subsea cutting operation.


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05.02.16

Platform LegCrack Termination

Case Study


Cracking discovered in the main caisson around a

vent exhaust duct on the platform leg.

The requirement was to machine an elliptical hole

into a 5m diameter platform leg.

Location: Siri Platform, Denmark.

Requirements

• Use the Mirage 3 axis gantry milling

machine.

• Workshop trials carried out in advance.

Solution

All machining operations were completed first

time, to customer’s specification and within

time critical operations window.

.

Outcome

Workshop trial.


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05.02.16

Tidal Fin Removal

Case Study


• Structural plates required removal from tidal

turbine monopoles.

• Diving time severely restricted to 20 minutes due

to tidal direction change and ‘Neap Tide’.

Requirements

• Plates (1.8m x 150mm x 30mm) removed

using a slitting saw. Remaining material

removed using face milling.

• Quick release tooling used to allow fast

project completion.

Solution

All machining operations were completed first

time, to specification and within time criticaloperations window.

.

Outcome

Workshop trials using the Mirage MR2000.


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05.02.16

Seam Weld andDoubler PlateRemoval

Case Study


• Remove a seam weld from 30” pipeline

over 3m length.

• Remove anode doubler plates for

relocation at 90m water depth.

• Location: North Sea.

Requirements

• Cold cutting to prevent cutting into the

parent pipeline.

• Use of Mirage gantry MR1000SS with

pipe chain clamping system, fixed feed,

and depth stops.• Workshop trials carried out on a circular

test piece.

Solution

• Milling of seam: less than 1 hour.

• Doubler plate removed in 3 hours.

Outcomes


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05.02.16

CIMV Removal& Torque ToolDevelopment

Case Study


The client’s problem was a subsea tree equipped

with a latch lock removal system on a chemical

injection valve which had a mechanical failure on

the connection rod.

Requirements

Mirage developed three innovative contingency

solutions to allow an ROV to remove the valve.

The first solution used a one inch, left-handed, four

flute endmill to attempt to turn the inconel rod to

unlatch the CIMV. This solution was delivered to the

Client’s design, but was unable to remove the

damaged valve.

Second solution: Having anticipated that a second

solution might be required, we designed and

engineered a contingency tool, which incorporated an

eight inch lathe chuck, with ROV handles, to deploythe latch onto the inconel rod, in an attempt to turn

the inconel rod to unlatch the valve. This tool was

successful in removing the valve.

Third solution: We designed an additional

contingency tool, which was a hydraulically operated

chucking system. This solution was not deployed, as

the valve was removed with solution two.

Solution

• The client’s problem was resolved.

• All three tooling solutions were provided in 10 days.

• Client requested we design a tool to prevent the

problem from occurring in the future.

Outcomes

The resulting torque tool created for

the customer.

Workshop development of contingency solutions.


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05.02.16

Injection Point in Trace HeatedSupply Line

Case Study


• To machine an injection point within a

heavy wall Super Duplex pipe.

• No swarf ingress or tool dwelling.

• One chance on offshore application.

Location: Islay Project, North Sea.

Requirements

• Mirage provided a complete

machine/offshore service package.

• A process was identified to series

trepan the external of the supply line.• Extensive workshop testing carried out

in advance.

• Machine used: HT50 Portable Drill

Solution

Client testimonial:

“ Did a great job offshore and everyone

was very pleased ”

Outcomes

Images above: Test pieces in the workshop.


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IndustriesMirage manufacture a range of portable machines for a wide variety of

applications and industries including:

Our products are supported by industry experts who work closely with our

customers to optimise performance for industry specific applications.

With extensive experience within service companies, our teams understand

the dynamics of a wide range of industries and have the capability to

deliver turn-key solutions that both meet specific requirements and address

complex challenges.

About Mirage MachinesMirage portable machine tools optimise the performance of on-site

assets by achieving operational excellence, maximising uptime and

improving productivity.

Our proprietary technology drives the development of the most reliable,

durable, efficient and precise portable machine tools on the market, that

are capable of delivering the most exacting standards of tolerance with the

highest quality output.

Our portfolio of portable machine tools are suitable for a diverse range of

on-site machining applications. Mirage have been granted ISO 9001:2008certification for our design and manufacturing systems

and we are able to provide full CE certification for our products.

• Oil & Gas • Mining & Construction

• Wind Power • Subsea

• Decommissioning • Utilities

• Ship Build & Repair • Nuclear

• Petrochemical • Power Generation


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Contact Us

UKMirage Machines

8-10 Enterprise Way

Jubilee Parkway

Stores Road

Derby DE21 4BB

T: +44 (0) 1332 291767

F: +44 (0) 1332 370356

E: [email protected]

SingaporeMirage Machines

107 Tuas South Avenue 8

Offshore Marine Centre 637036

Singapore

Tel: +65 9855 0117

[email protected]

PerthMirage Machines

15/4 Wharton Road

Kewdale

WA 6105

Tel: +61 0 452 48 1964

[email protected]

HoustonMirage Subsea Inc.

8615 Jackrabbit Rd

Houston

TX 77095

United States

Tel: +1-281-859-1234

E: [email protected]

mm subsea case study pack

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