Gas separators are vessels designed to separate natural gas from liquids, which are intimately mixed together as they flow from the wellhead. The design of high pressure and low pressure separators are essentially the same. Low pressure separators are commonly used on low volume wells or downstream of high pressure separators to provide additional release of entrained gases.
  • TWO PHASE:

The wellstream enters the vessel and is spread outward by the inlet diverter initiating primary gas separation. The liquids fall to the bottom or liquid section of the separator. As the liquid level rises a level controller activates a dump valve discharging the oil and water to a treating system for further separation.

The gas expands and flows upward throughout the gas settling section. The reduction in velocity and pressure allows the liquid particles to settle out into the liquid section. The gas continues upward and flows through a wire mesh mist extractor for additional scrubbing.

  • THREE PHASE:

The three phase separator is essentially the same as the two phase except that internal construction allows for the separation of oil and water in addition to entrained gas. Production enters the vessel into a downcomer pipe on the low pressure separator and an inlet section on the high pressure separator, which can be viewed on their respective illustrations. The gas flows upward into the gas settling section as the liquids drop and gravity flow through the downcomer to be dispersed by a spreader plate.

The three phase separator has a larger liquid section allowing for more retention time. The oil and water levels are maintained by independent level controllers that activate the appropriate dump valves. The liquid capacity of a three phase separator is dependant upon the gravity differences of the oil and water. A separator will not break emulsions. The oil and water must be present as free liquids.

 

Horizontal separator has a greater cross sectional interface area than that of a vertical separator, which greatly increases the gas-liquid separating capacities. Horizontal separators are ideally suited for wells having high gas-liquid ratios, also the large interface area aids in the release of solution gas and reduction of foam. Horizontal construction is ideal for skid mounting and stacking in a piggyback fashion for stage separation packages that reduce space requirements. 

 
 

 

Vertical separators use much less floor space than horizontal separators do, therefore making them ideally suited for tight or compact circumstances. Low to medium gas-oil ratio wellstreams are also  a good environment for the vertical separator