The essence of all petroleum multiphase pressure boosting is to be able to transport the well fluids from the reservoir to processing facilities. In a general approach for such a gas and oil development-like the Poseidon concept-pressure boosting is as essential as a beating heart. On the other hand, there are-as in the living body-other parts just as essential for stable operation. In the attempt to meet the challenging technical problems of the booster, the importance of reservoir monitoring, pipeline and flow design, and the behaviour of hydrate, wax, emulsion and corrosion should not be underestimated.
I shall review the main options available for the concept designer in maintaining the steady flow of oil and gas. Since the circumstances change and great effort is continuously being put into developing new machinery, this contribution can only cover the field incompletely and as of winter 1989. The scene is the North Sea or the Norwegian Sea, with field installation on subsea template or unmanned wellhead platform (Fig. 1). The well fluids produced should be transported to a distant process facility on an existing platform or onshore.
The concept designer might face a transport problem in one of three categories:
natural depletion is sufficient;
reservoir pressure needs to be maintained; or
transport of well fluids needs boosting
The main factors are reservoir conditions such as initial pressures, driving mechanisms and fluid properties, or ‘geographical’ conditions such as distance to process facilities, water depth and bottom topography(Fig. 1 is available in full paper)
When adequate, it is the obvious low-investment, low-complexity option. Cases have been seen with gas-condensate fields or with excellent water drive in the reservoir.
Limitations are in most cases severe in terms of transport distance, field life time and recovery. Nevertheless it can lead to an important delay of pressure-boosting investment. Such delay can be short-a couple of years-but is more significant when it reaches 10-15 years after production start-up.
With specific reservoir behaviour as the background, water or gas injection also has transport consequences as well. Cases abound in which the oil-producing capabilities of a petroleum reservoir are dependent on maintaining the pressure level in the reservoir Water or gas injection will then give a high flowing wellhead pressure over the entire field lifetime. As a consequence, the well