Pars Technic

Basic Operation of Three Phase Separators

An oil/gas separator is a pressure vessel used for separating a well stream into gaseous and liquid components. They are installed either in an onshore processing station or on an offshore platform. Based on the vessel configurations, the oil/gas separators can be divided into horizontal, vertical, or spherical separators.

In teams of fluids to be separated, the oil/gas separators can be grouped into gas/liquid two-phase separator or oil/gas/water three-phase separator. Based on separation function, the oil/gas separators can also classified into primary phase separator, test separator, high-pressure separator, low-pressure separator, deliquilizer, degasser, etc.

To meet process requirements, the oil/gas separators are normally designed in stages, in which the first stage separator is used for priliminary phase separation, while the second and third stage separator are applied for further treatment of each individual phase (gas, oil and water).

Depending on a specific application, oil/gas separators are also called deliquilizer or degasser. The deliquilizers are used to remove dispersed droplets from a bulk gas stream; while the degassers are designed to remove contaimined gas bubbles from the bulk liquid stream.

Conventional oil/gas separator names:

  • Oil/gas separator
  • Gas/liquid separator
  • Degasser
  • Deliqulizer
  • Scrubber
  • Trap
  • An oil/gas separator generally consists of following components:

  • Inlet device located in pre-separation zone/section for priliminary phase separation;
  • Baffles downstream the inlet component to improve flow distribution;
  • Separation enhancement device located in the primary separation (gravity settling) section for major phase separation;
  • Mist extraction device located in gas space to further reduce liquid content in the bulk gas stream;
  • Various weirs to control the liquid level or interface level
  • Vortex breaker to prevent gas carryunder at outlet of liquid phase;
  • Liquid level/interface detection and control, etc.;
  • Gas, oil, water outlet;
  • Pressure relief devices

  • Sketch of 3 phase Separator

    6 Ways to Separate an Oil and Water Emulsion

    4 Types of 3-Phase Separator Tank

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