Abstract: Water-in-oil emulsions, particularly used invert water-in-oil drilling fluid, are separated into an aqueous component and an oil component by passing the emulsion through a knock down tube having an outer member, the outer member having a receiving end and a terminal end, the receiving end receiving the heated invert water-in-oil drilling fluid, an inner member, substantially coaxially disposed with the outer member, said inner member defining a plurality of apertures through which separated oil passes into the outer member, at least one exit port for a separated oil phase to leave the knock-down tube, said exit port defined by the outer member; at least one compressed air entry in air communication with the source of compressed air, and an exit port into a conduit passing through a filter means for the aqueous phase defined by the terminal end of the knock-down tube; heating the emulsion, and pressurizing the heated emulsion. The separated components are recovered and stored for recycling or disposal.