Abstract: A method and apparatus for providing a preliminary separation of production fluid. A vessel (1) has an annular inlet (5) opening upwardly at the bottom of the vessel. The inlet has means (4) for causing the mixture to swirl to generate a vortex. A first outlet (8) for an oil continuous flow is provided at the center of the annular inlet. A second outlet (10) for a water continuous phase is provided towards the bottom of the vessel and spaced from the first outlet. The oil and water are separated under centrifugal forces caused by the swirl and the oil is drawn down through the center of the vortex for discharge through the first outlet (8).