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Contenuto archiviato il 2022-12-27

ABRASIVE JETTING APPLIED TO PLATFORM DECOMMISSIONING

Obiettivo

The aims of the project were :
- The hyperbaric evaluation of abrasive water jet equipment and the
development of a specific subsea cutting tool as a complement to explosive
cutting and other cutting techniques for platform removal application.
- The development of a typical operational scenario for
the offshore deployment of abrasive water jet and explosive cutting
in order to optimise safety and minimise costs.
- The study of methods for operationally deploying both abrasive water
jet and explosive cutting as a function of different worksite
characteristics.
See also project nr. OG./00219/90/FR/..
HYPERBARIC TESTS GENERAL FEATURES
- 60 hyperbaric cycles performed (310 cuts)
- 17 different materials tested (27 configurations)
- 7 grade of abrasive tested (12 tonnes)
- 4 different cutting head positions
- up to 300 bar long cutting umbilical.
TESTS RESULTS
1) AMBIENT PRESSURE : No significant influence of pressure at 50 bar
2) ABRASIVE CHOICE : Best choice was high density medium hardness
copper slag abrasive
3) FLEXIBLE CONNECTION : Very good resistance to abrasion
4) NOZZLE STAND-OFF : Best stand-off distance was determined
5) CUTTING HEAD ORIENTATION ANGLE : Not significantly influent on cutting
performances
6) CUTTING SAMPLES
a) HOMOGENEOUS MATERIALS (STEEL) : Very good results at any depth.
Cutting speed between 1/2 to 4"/mn depending on wall thickness.
b) MULTI-LAYERS STEEL MATERIALS : Good results at any depths.
Cutting speed between 1/2 to 3"/mn (same as above).
c) FLEXIBLE PIPELINES (COFLEXIP) : Very good results at any depths up
to 500 m. Cutting speed between 2 to 3/mn.
d) REINFORCED CONCRETE : Poor results for thickness above 150 mm.
Maxi depth 200 m, rebars not cut.
e) SANDWICHES CONFIGURATIONS : Good result for concrete coated pipelines
when concrete coating was less than 25 mm thick.
Poor results to very poor results when trying to cut several layers
of steel and concrete.
f) MISCELLANEOUS ITEMS : Good results at any depth for chain link cutting,
steel cables, ROV Kevlar umbilicals and shacke.
Cutting speeds for above item have to be inferior to 50 mm/mn for
reliability of cuts.
5.3 CUTTING QUALITY ASSURANCE
The system has to be operated by very specialized technician.
Very good results for bevelled cuts which does allow direct welding.
Kerf quality is related to the material's hardness and to the cutting speed.
Cutting quality range from bad (sandwiches) to very good (steel).
5.4 VERSATILITY
This technique can be easily suited to work in remotely operated mode.
5.5 PRODUCTIVITY
Cutting rate and capabilities are excellent.
Important maintenance work is essential.
The entire system can be easily integrated within a 20' container.
Still plenty of room for improving the system performance.
The programme consisted of three work packages :
WORK PACKAGE NR 1 : "DEVELOPMENT AND HYPERBARIC TESTING OF AN UNDERWATER CUTTING SYSTEM BASED ON ABRASIVE WATER JET TECHNQIUE'
- Evaluation of an abrasive water jet system including an abrasive metering
and feeding device.
- Necessary development to optimise system components.
- Exhaustive hyperbaric tests to define cutting parameters for different
samples (materials and configurations) over a range of significant
simulated water depths (0 to 500 m).
- Work package achieved by COMEX.
WORK PACKAGE NR 2 : 'OPERATIONAL TECHNIQUES RELATED TO PLATFORM DECOMMISSIONING AND TO ASSOCIATED UNDERWATER CUTTING OPERATIONS'.
WP 2.1 : "Identification of platform to be removed".
* creation of an offshore structure data base aimed to provide specific
information needed to achieve decommissioning cutting tasks,
* market assessment and outline review of the various removal procedure,
* work package jointly achieved with AME LTD and TECNOMARE SPA.
WP 2.2 : "Interactivity between removal procedures and the cutting operations".
* new development on abrasive water jet techniques
* outline procedures for cutting operations
* work package jointly achieved with AME LTD and TECNOMARE SPA.
WP 2.3 : "Specifications of the deployment systems required for installation remote control, monitoring of the dedicated cutting equipments".
* general specifications of deployment systems needed to perform abrasive
water jet or explosive cutting (AME LTD),
* BP MAGNUS platform crack repair feasibility tests and offshore trials,
* OSEBERG 2 pipeline cutting project : specification of a fully remotely
operated dedicated cutting system for diam 16" pipelines,
* work package achieved by COMEX.
WORK PACKAGE NR 3 : "BASIC AND DETAILED ENGINEERING OF ASSOCIATED EQUIPMENT".
* revised scope of work approved by the EEC
* deployment by ROV
- existing ROV capabilities inventory
- cutting configurations (platform and pipeline)
* deployment by dedicated robot
- selection of tubular members diam between 16" to 36"
- specifications and engineering design of a dedicated robot system
* work package achieved by COMEX.

Invito a presentare proposte

Data not available

Meccanismo di finanziamento

DEM - Demonstration contracts

Coordinatore

STOLT COMEX SEAWAY SA
Contributo UE
Nessun dato
Indirizzo
CHEMIN DU LITTORAL 467 - B.P. 69
13321 MARSEILLE
Francia

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Costo totale
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