Separating a stream containing a multi-phase mixture and comprising lighter and heavier density liquids and particles entrained therein

摘要

A separation method and apparatus are disclosed having particular application for effecting removal of sand from a production wellstream, enhancing the quality of recovered oil, gas and water output streams (12, 13, 14) and reducing erosion caused by entrained sand. The wellstream is passed initially through a cyclone separator (4') which separates substantially all the water and sand as underflow and substantially all the oil and gas as overflow. A gravity separator (11) separates the overflow from the cyclone separator (4') into oil, gas and water, and a further cyclone separator (17) separates the underflow from the first cyclone separator (4') into water and sand.