In the early 90's and upon the foreseen challenges for producing offshore fields, particularly in deep and ultra-deep waters, PETROBRAS structured a corporate R&D program devoted to the development of a set of technologies found crucial for the success in such scenario - the PROCAP 2000. Among the technologies pursued in such Program there was the multiphase boosting technology. This technology was then approached under three distinctive routes:
electrical submersible pump (ESP) applied to wet completion;
sub sea gas-liquid separation followed by liquid pumping; and,
untreated multiphase pumping. This paper is associated with the last two mentioned routes by describing their main representatives and the acquired experience in their development and application.
The development of deep and ultra deep water fields, particularly when they are marginal in profitability and or associated with flow assurance issues (e.g., viscous oils, prone to emulsion formation, organic deposition and/or gas hydrate) represent one of the most challenging issues in offshore technology. In addition, some offshore areas have now become mature, which can be considered as mainly translated by a decline in the oil production followed by a substantial growth of the water production. In such scenario irrupts most of the collateral and undesirable situations for production and thus jeopardizing the continuity of such operation. However these areas are also typically characterized by an extensive pipeline and flow line network, a high degree of integration and, in most situations being the existent platforms located in the proximity of new developments.
Upon considering that the main purpose of the sub sea multiphase boosting system (SSMBS) innovative route is to transfer the untreated multiphase (oil, gas, water and eventually occurring solids) production, from wellheads or manifolds (both laying on seabed), also reveals the characteristics of its main niches of application, as follows:
making technically viable and/or enhancing the benefits of a new deep water production;
making possible a long tie-in of a new development (possibly in a deep or ultra deep water location) to an existent and showing some idling capacity platform (possibly in shallow waters); and,
making possible to sustain profitable conditions in a mature field production.
Among the benefits foreseen with the deployment of a SSMBS, one shall find some of the following ones (Ref. 1).
The SSMBS can be understood as an artificial and additional source of energy, which is going to be added to the natural one provided by the reservoir. The synergic combination of these two sources will naturally allow a faster production of fluids and consequently anticipating revenues.
The SSMBS can under a fast track provides knowledge of a recent discovery. In these days in which the allowed time between the field discovery and its development is each time shorter, such feature shall be much appreciated.