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).

Abstract: Particles of sand coated with oil are loaded into a housing (1). A fluidizing unit (3) is provided towards the bottom of the housing. The fluidizing unit fluidizes the particles and discharges them from the housing to a separator, such as one or more hydrocyclones (8, 14), in which the oil and sand particles are separated. The coated particles can be introduced in the housing (1) via a cyclonic separator (50, 52) which provides some preliminary separation.

Abstract: A fluidising unit (1) comprising a supply duct (2) which is arranged to be fed with liquid under pressure, and a discharge duct (5) within the supply duct and projecting beyond the outlet of the supply duct. The end of the supply duct (2) is closable when the fluidising unit is not in use. A screen (9) is associated with the supply duct (2), the screen having at least one oblique opening (10), and being positioned so that liquid passing through the supply duct passes through the or each opening in the screen and is caused to swirl.