Decommissioning of offshore installations in the ... . Ramboll. Decom in...

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Transcript of Decommissioning of offshore installations in the ... . Ramboll. Decom in...

  • Decommissioning of

    offshore installations in

    the operational phase

    Kristian Lund Jepsen

    Ramboll Oil & Gas

  • 2SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Two types of installations two types decom

  • 3SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Reasons for decom at fixed installations

    Equipment redundant from day one

    Equipment/system process wise outdated

    Demolition

    Equipment/system technological outdated

    Equipment failed / worn-out

    Replace with equipment / systems that fits changedprocess conditions

    Replace with modernequipment / systems withnew technology

    Refurbish / Repair

    Replace (1 : 1)

  • 4SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Redundant from day one - example

    Gas fired heater back-upfor turbine WHRUs

    Other examples:

    Mud tanks

    Well kill system

    Runway beams

    Trolleys/chain hoists

  • 5SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Process wise outdated equipment

    Increased amount of produced water

    Change from HP separation to LP Mode

    Change in gas composition / mole weight

    Change in gas composition increase of H2S + CO2

    Increased amount of oil/gas

    Debottlenecking of complete process train

    Debottlenecking of produced water system

    Larger pipe dia, larger volume in separators

    Re-bundling of centrifugal compressors and larger driver

    Change piping matr. class from CS to duplex

  • 6SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Technological outdated equipment - examples

    Pneumatic analog instruments

    F&G Detectors / systems

    Control / ESD Systems

    Control panels for gas compressors

  • 7SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Examples worn-out equipment

  • 8SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Heat exchangers for cleaning/refurbisment

  • 9SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Decommissioned stay in place

    Runway beams aredecommissioned to avoid periodicinspections / tests.

  • 10SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    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 filledgaskets)

    Scale may be barium orstrontium sulphate which is NORM material.

  • 11SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    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 platform for calculating the amount of equipment operational decommissioned yearly.

    Assessed the Customs Authorities to obtain information about import from offshore installations.

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

  • 12SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    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

  • 13SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Estimate Model. All Danish offshore fields installedpiping / decomissioned piping and totally decommissioned

    Estimated piping (incl. valves) from Danish offshore platforms decommissioned yearly

    Installation

    year 1987 and before 1987 - 1997 1997 - 2007 Totally

    Age 20 years and more 10 - 20 years 0 - 10 years

    Piping (tons) 6923 4825 3400 15148Scrap/change-

    out % yearly 10 5 2,5Scrapped piping

    - tons yearly 692 241 85 1018

    Totally decommissioned from Danish offshore platforms yearly - estimated tons:

    Piping 1000

    Mech. Equipm. 500

    Structures 250

    Elect/Instrum 200

    Other 50

    Totally 2000

    The model is based on a life time of 20 -25 years of an installation.

  • 14SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    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

  • 15SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Jack-up rig conversion / decom

    Maersk Giant:

    Converted to oil/gas production 1996.

    Production package owned by Schlumberger.

    Produced on Yme Field 1996 2001, operated by Maersk Contractors.

    Decommissioned production packagedemolished in Esbjerg Port 2001. Packagetaken over by Hannover Company

    The rig converted back to drilling.

  • 16SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Statoil preparations to decom. HSE / NORM

    Study of consequences (Konsekvensutredning Ymeavslutningsplan).

    Included evaluations regarding HSE impacts.

    Included evaluations regarding NORM it was concluded there was no NORM as seawater had only been injected for a short period in the initial stage of the project.

    Samples of scale in the production equipment was taken.

    Concluded that scale was not radioactive and that it was calciumcarbonate.

  • 17SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Maersk Giant towing in 2001

  • 18SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Maersk Giant at the port side

  • 19SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Maersk Giant production package onboard

  • 20SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Maersk Giant equipment being lifted off

  • 21SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    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 to Hannover Company for possible re-use

  • 22SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Yme production package. Summer 2007

  • 23SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Mobile offshore units. Decom status.

    Yearly 2 units in the harbour.

    Equipment decommissioned/scapped yearly: 500 tons 2000 tons

  • 24SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Total status. Decom. Tonnes handled yearly

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

    Total 3000 - 6000

  • 25SlideOctober 15, 2007Basic Ramboll Oil & Gas PPT

    Conclusion

    The amount (tonnes) of equipment decomissioned/scraped and then handled in the harbour of Esbjerg yearly corresponds to the weight of one medium size topside.

    The experience exists and the companies to handle the waste and 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.