A 3-phase separator is a pressure vessel that splits a well stream into gas, oil, and water using gravity separation: gas rises to the top, oil floats in the middle, and water settles at the bottom.
Key Points
Internal Components & Process:
*Inlet Diverter: Knocks out bulk liquids from the incoming fluid stream.
*Settling Zone: Holds liquid for 3–10 minutes so oil and water can separate. An overflow weir isolates the separated oil.
*Mist Extractor: Traps fine liquid droplets before gas exits through the top.
*Coalescing Plates: Help small liquid droplets merge and separate faster.
Horizontal vs. Vertical:
Horizontal: Best for high liquid volumes and fast droplet settling; requires a larger footprint.
Vertical: Ideal for high gas volumes, sand-heavy streams, or tight footprints (like offshore platforms).
Critical Factors: Requires precise level/interface control to avoid carryover (liquid in the gas stream) and carryunder (gas trapped in the liquids), along with adequate residence time to handle emulsions.