New Way To Use Pipes For Subsea Separation In Deepwater Development And Qualification Of A Novel Gas/Liquid Separator

The subsea separation and boosting of the produced liquids from the associated gas is recognized to be an efficient way to enhance oil production, taking advantage of liquid pumps capacity to decrease backpressure at wellheads. This configuration will be used as a first field application on Pazflor by Total.Traditionally, gas/liquid separators are made of a big pressure vessel giving the space required for gravity separation. For subsea application, these pressure vessels would be designed to resist to hydrostatic pressure which leads to very thick shells when going in deepwater. For such thick pressure vessels, the delivery time is increased by specific manufacturing requirements, impacting project cost and schedule. Saipem has developed a solution for gas/liquid separation, keeping the standard process of gravity separation, but using pipes instead of pressure vessel, thus facilitating manufacturing, reducing mean time and being compliant with local fabrication facilities on yard. The principle of this multipipes separator is to divide the area of a single pressure vessel into several pipes that are fed in parallel with the multiphase flow and in which the gravity separation occurs. The wall thickness is then reduced compared to single pressure vessel, extending application for deepwater fields.A qualification program has been launched and first results are expected for the beginning of 200