Abstract: The invention provides a method of phase separation of a hydrocarbon containing mixed phase fluid composition into at least two separted fluid phases which method comprises introducing (8) a hydrocarbon-containing composition into a phase separator (1) and withdrawing at least two said separated fluid phases (12, 13, 14) from said separator (1), whereby a lipophilic liquefied gas is simultaneusly introduced (24, 19, 17) into said separator (1) with said composition or, preferably, into a fluid-filled region of said separator (1).