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Compact subsea separator with integrated sand management system

Development of an ultra compact subsea water separation concept with an integrated sand management system to save costs in hydrocarbon production.

Separation equipment fulfils a critical role in the oil and gas production process; it ensures that the well fluids, which are a wild mixture of oil, gas and polluted formation water when they are produced, are split into their more or less pure constituents that can then be further processed. This separation process is one of the most important process steps out of all the oil and gas production processes, because without it being carried out effectively and efficiently, the subsequent steps ranging from gas dehydration and/or gas compression to water cleaning before disposal could not take place. Oil companies require innovative, more efficient and smaller separators. The reason for this requirement is twofold. The first reason is that the smaller a separator can be designed, the lower the capital investment will be that is required to exploit a new field. As explained above, the size of a separator has a direct and strong influence on such economic considerations. The smaller the separator can be, the easier 'marginal' fields can be economically exploited. The second reason is related to the fact that when an oilfield ages, its production decreases. Continuously more water and / or gas are co-produced with the oil. The total production flow becomes limited by the process system, which needs to separate increasing amounts of water and gas from the oil stream produced. This normally translates in a situation in which the total amount of oil production decreases. If separation equipment becomes available that can separate higher flows of water and/or gas from the oil, it becomes possible to de-bottleneck the existing separators by installing stronger performing 'internals' into the vessels. In this way, the decision to shut down an oilfield can be postponed and consequently the field can be deeper exploited. The programme aims to qualify an ultra compact subsea water separation concept with an integrated sand management system. The concept is based upon state-of-the-art topside separation technology from CDS ENGINEERING BV. The qualification work will be carried out with close co-operation between CDS and FMC KONGSBERG SUBSEA. The solids management system is based upon use of the Merpro Tore technology. MERPRO LTD. will also play an active role in the sand management work in the programme. A separate activity for evaluation of an alternative sand removal concept from CYCLOTECH LTD is also included. The qualification programme will be based on Computational Fluid Dynamics work and extensive testing both in small- and full-scale test setups. The test systems will be incorporated in the existing CDS test facilities in Arnhem, the NETHERLANDS. A summary of the activities is shown in points 1 to 4. Task 1: Computational Fluid Dynamics (CFD) modelling - design work. Modelling of three-phase flow in the proposed subsea separator design to optimise gas/liquid, liquid/liquid and sand separation efficiency. Task 2: Laboratory tests small scale. A small-scale model of the subsea separator will be used for testing gas / liquid and sand separation performance at atmospheric conditions. Task 3: Full scale laboratory testing at atmospheric conditions. A full scale separator will be manufactured and tested on: a) Gas liquid separation b) Liquid liquid separation c) Sand separation Task 4: Full scale laboratory testing at high-pressure conditions: items a), b), c) from task 3 will be verified under high gas density conditions. The process conditions for these tests are the same as present in the NORNE field and the large-scale test separator size is equal to the proposed separator size for the NORNE field. The results of the subsequent tasks will be the input for a go / no go decision for the next proposed task in the project. Keywords: subsea, separator, oil-gas exploration.
Acronym: 
SUBSEA SEPARATOR
Project ID: 
3 040
Start date: 
12-03-2003
Project Duration: 
14months
Project costs: 
1 900 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.