FIELD: underwater oil and gas production. SUBSTANCE: method and apparatus serve for efficiently combating piston motion of liquid and thereby separating liquid phase of gas-liquid mix from gas phase. Braking plate contained inside casing decelerates motion of liquid pistons and thereby provides separation of gas. Decelerated liquid passes gh4 openings of braking plate and leaves the casing. Whereas separated gas rises above braking plate and separately leaves the casing. Liquid and gas streams can be joined anew or be kept in disjoined state for subsequent treatment. EFFECT: improved condition of oil and gas production. 10 cl, 6 dwg
