Objective
This project aims to reduce in a significant manner offshore development costs, either by reducing equipment weight and consequently reducing the weight of the overall structure, or by reducing equipment costs.
Phase 1 - Evaluation and control of execution of offshore projects.
A computing tool named SPOT capable of simulating a conventional offshore project has been developed.
On the basis of parameters accessible to the operator, this simualtion enables the elements of the project to be evaluated in terms of the following factors :
- technical description
- project planning schedule and manning requirements
- cost (in the different countries of implementation)
- investment programme
SPOT comprises the following modules :
- superstructures (surface installations),
- metal structure (jacket) (water depth from 50 to 200 m)
- offshore installation operations
- hook-up
- metal structure for water depths of less than 50 m
- subsea lines
- concrete gravity structures.
These modules are completed by a data bank set up on the basis of offshore oilfied developments, particularly those located in the North Sea.
Many tests have been carried out on a real cases embodied or not in the initial data base; the results have invariably proved highly satisfactory. The overall results very rarely stray beyond +/- 10%.
The SPOT model predicts the final result in terms of planning schedule, cost, investment programme and manning requirements. Not only does it enable the technical scheme of a development project to be optimized when the decisions are taken, but also the development itself to be controlled during the construction phases and subsequently the operating phases.
SPOT is par excellence a comparison tool and consequently an aid for decision-making, but does not claim to replace the studies usually carried out, once the development decision has been taken.
Phase 2 - Lightening of the metal structures.
A program using integral equations enables the behaviour of a metal part with a fault in it to be computed and the corresponding risks of brittle fracture to be evaluated. However, the specificity and complexity of the computing operations does not enable it to be built into a general application program of the STRUDL type, as had originally been envisaged.
In addition, a model for introducing a rigidity junction node matrix into the structural design program has been established.
Phase 3 - Lightening of the treatment equipment.
With regard to study of tangential filtration of the injection waters, promising results were obtained with ceramic membranes, though a clogging phenomenon was noted when using reservoir waters, which may render use of these membranes doubtful.
Elsewhere, study of new degassing systems of the injection waters enabled the processes proposed by NEYRTEC(F), B.H.R.A. (UK) and NORSK HYDRO (Norway) to be evaluated.
Lastly, following an initial technico-economic evaluation, it turns out that buffer storage of the gas for flaring represents only a limited interest. This has led to studying a method of protection against overpressures enabling the importance of the flaring systems to be reduced.
The project is divided in three phases :
1. Evaluation and supervision of offshore projects.
Using the simulation modelling, this phase aims to develop software which will be applied in real cases in the North Sea. This software will be extended to other areas.
2. Weight reduction of metallic structures.
This phase will improve the present calculation methods on two points : fragile breaking-down and flexibility of the tubular nodes.
3. Weight reduction of processing equipment.
The study concerns the processing equipment for injected waters and the flaring equipment.
The arrangements described below have been approved by Lloyds Register adn DNV.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
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