Objective
Development of a floating production system for exploitation of oil fields in very deep waters in the Mediterranean sea, reference case the Aquila field.
The project has demonstrated that the concept of the Tension Leg Platform proposed is feasible and it can be used as floating production system for the production of deep water Mediterranean oil fields.
The TLP is basically composed of a floating hull which tensions a system of vertical tethers connected to the base.
The concept may be subdivised into four main subsystems :
- Platform consisting of a double symetric semisubmersible unit having four cylindrical columns connected by pontoons and an integrated deck designed to house process plants and auxiliaries.
- Anchoring system made up of 16 tendons (4 per column) that are composed of steel pipes welded together during the platform installation phase.
- Foundation made up of 4 piled bases connected 2 by 2 by means of a lattice structure provided in order to facilitate and reduce operations.
- Completion consisting of : eight production risers, four water injection risers and one export riser connected to the well template whichhas 16 slots.
- Specific criteria were developed to analyse hydrodynamic aspects, in order to have a correct assessment of tether forces and overall motion of the platform. It was found that tether loading was essentially driven by the platform response to the waves at their own frequencies, whilst a large contribution to the overall (unconstrained) motions of the platform came from long drift effects.
As a consequence, the analysis procedure was built up in such a way as to have correct characterization of the platform motions in both mentioned aspects.
Fatigue of the tethers was checked by means of a stochastic approach to take properly into account the contributions of the sea states occuring during lifetime.
Model tests have been also carried out in a pool and in a wind tunnel.
Analysis and selection of the production system configuration with definition of its main components (platform, risers, tendons, etc.). Development of computer procedure for hydrodynamic and structural analysis. Preliminary design of the floating platform and of the other main subsystems. Definition of construction and installation procedures. Model testing of the platform in ocean basin. Cost of schedule evaluation.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
20097 S. Donato Milanese (MILANO)
Italy