Objective
The final aim of this project is to adapt or develop, built, experiment and validate an abrasive jet cutting system suitable for platform decommissioning replacement or repair.
This project will allow to develop a remotely controlled system, potentially operated in full robotic mode, and which will be deployed without diver assistance within the above described scope of work.
Within the framework of the above process, this project aims to solve the sandwich materials cutting limits that were encountered during the previous CEC contract nr TH./06048/88/FR.
The most significant innovative aspect is concerning the direct injection to the cutting head of an abrasive slurry of 700 bar pressure instead of 350 bar for the previous project.
During a 5 month period, more than 100 tests have been carried out and the Diajet 700X2C prototype has been modified.
Main results :
* Diajet unit reliability became acceptable and its efficiency increased,
* copper slag abrasives remain the best abrasive quality to use,
* significant differences in cutting efficiency when varying the water depth from 0 to 50 m. These differences are probably to the size and configuration of our testing chamber.
* no evident correlation between the cutting noise and the cutting efficiency,
* cutting efficiency can be monitored by use of ultrasonic technique.
We also prepared an operational offshore procedure and developed an internal Abrasive Jet Cutter (I-JAC) which was the base of a new generation of tool.
PROJECT PROGRAMME IS:
- extend the limits of cutting efficiency by upgrading the 350 bar abrasive metering device used during previous project to a 700 bar unit.
- develop, fabricate and test thoroughly in hyperbaric condition the new abrasive jet parameters to cope with existing configurations where previous tests were not successful (concrete + steel sandwich).
THE PROJECT IS SPLIT IN THE FOLLOWING PHASES :
PHASE ONE (1991/1992)
- cutting capabilities and efficiency upgrading oriented towards larger wall thicknesses and sandwich materials) - upgrading of equipment
- validation by hyperbaric tests
PHASE TWO (1992/1993) :
- definition of equipment and procedures in order to cope with :
- complex and large wall thickness cases
- automatic remote control mode
- alternate ROV based operation
NEW DEVELOPMENT OF THE PROJECT :
Within the framework of project nr. OG./00233/92/FR, we developed, fabricated and validated through shallow water and offshore tests a new abrasive jet cutting subsea deployment system which copes with the cutting requirements linked to a medium size jacket platform removal. The offshore validation was indeed performed during the Hamilton Forbes platform decommissioning.
OTHER FUTURE DEVELOPMENT :
- concrete demolition inside grouted steel pipes. This technique could also be applied to concrete removal on concrete coated pipes.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
13321 Marseille Cedex
France