2a. Ramboll. Decom in Operational Phase

7/29/2019 2a. Ramboll. Decom in Operational Phase

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Decommissioning of

offshore installations in

the operational phase

Kristian Lund Jepsen

Ramboll Oil & Gas


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2SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

Two types of installations two types decom


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Reasons for decom at fixed installations

Equipment redundantfrom day one

Equipment/systemprocess wise outdated

Demolition

Equipment/systemtechnological outdated

Equipment failed /worn-out

Replace with equipment /systems that fits changedprocess conditions

Replace with modernequipment / systems withnew technology

Refurbish / Repair

Replace (1 : 1)


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Redundant from day one - example

Gas fired heater back-upfor turbine WHRUs

Other examples:

Mud tanks

Well kill system

Runway beams

Trolleys/chain hoists


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Process wise outdated equipment

Increased amount ofproduced water

Change from HP

separation to LP Mode

Change in gascomposition / mole

weight

Change in gascomposition increaseof H2S + CO2

Increased amount ofoil/gas

Debottlenecking ofcomplete process train

Debottlenecking ofproduced water system

Larger pipe dia, larger

volume in separators

Re-bundling ofcentrifugal compressors

and larger driver

Change piping matr.class from CS to duplex


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Technological outdated equipment - examples

Pneumatic analog instruments

F&G Detectors / systems

Control / ESD Systems

Control panels for gas

compressors


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Examples worn-out equipment


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Heat exchangers for cleaning/refurbisment


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Experiences from operational decom

Dangerous lifting operations(unknown weight+COG)

Handling of NORM (NaturalOccuring Radioactive Matr)

Handling of chemical/oil waste

No asbestos in insulation(however: Flange Insulationkits, Carbon-Asbestos filled

gaskets) Scale may be barium orstrontium sulphate which isNORM material.


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Estimates tons metal scrap per year

Detailed data from one platform backload to shore during one

year.

Assumed a model partly based on above data from one platformfor calculating the amount of equipment operational

decommissioned yearly.

Assessed the Customs Authorities to obtain information aboutimport from offshore installations.

Assessed the oil Companies (DUC/Mrsk Oil, Hess, DONG E&P)


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Backload Logistics and Handling

Return Goods

/ Supply Boat

Well Service

Company

Equipment

Waste skips

Chemical Tote

Tanks

Backload

Containers /

Baskets

Large scrap

items

To Service company

Not dangerous

waste

Chemicals/oil

waste

Empty - send

to Kommune

Kemi

Empty -

normal

renovation

Waste to Kommune Kemi

Tank Cleaning

Waste to Kommune Kemi

Refill Tote

Tank

Sorting /

Evaluation

To Service /

Repair

company

To be Stocked for

later use

(OIL COMPANY'S

STORE)

To be sold for

re-use

Repair /

scrap

Repaired/

To stock

Supply Goods

/ Supply Boat

Scrap Yard

Scrap

Repaird - directly return to offshore

Costums area


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Estimates from the 3 operators in Danish sector

DUC/Mrsk Oil

Hess Denmark Aps

DONG E&P

Totally: 3100 tons 3400 tons yearly

Variations: 2500 4000 tons yearly


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Maersk Giant production package onboard


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Maersk Giant equipment being lifted off


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Maersk Giant 2001 Decom/Conversion

Noise / Fire Walls around package removed

Flare tower removed

Production package removed from deck

All interconnecting piping and cabling removed

Totally: 1200 tons removed

Production package, 800 tons, sold from Schlumberger toHannover Company for possible re-use


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Mobile offshore units. Decom status.

Yearly 2 units in the harbour.

Equipment decommissioned/scapped yearly: 500 tons 2000tons


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Total status. Decom. Tonnes handled yearly

From fixed installations 2500 - 4000From mobile offshore units 500 - 2000

Total 3000 - 6000


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Conclusion

The amount (tonnes) of equipment decomissioned/scraped and

then handled in the harbour of Esbjerg yearly corresponds to theweight of one medium size topside.

The experience exists and the companies to handle the wasteand scrap are used to handle these items.

Large heavy lift cranes (Thialf) cannot go into the harbour.

Need for companies who can handle and clean scrapped piping

and equipment for NORM.

Need for long-term storage facilities for NORM.

2a. Ramboll. Decom in Operational Phase

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