Definition(s)
Pressure Vessel –Phase Separation
First Option. Single four – phase separation vessel using velocity drop in the first compartment to create gas and solids phase separation. Liquids cascade to the back compartments where with sufficient residence time the interface forms. Requires sufficient time for the interface between liquids to take place which means the vessel has to be correspondingly large to accomplish the process.
Second Option. A series of vessels designed to separate the phases sequentially. Order of phase separation may vary from system to system. Different systems available are: Gas to be separated first as it is compressible and of lower density than solids or liquids. Remove solids first as they will erode pipe work and components in the system. Separation of gas, solids, and liquids occurs in individual hydro-cyclones connected in series, parallel, or a combination of both. In all separators, the design should make it impossible for gas to travel down the liquid leg and liquid to travel down the gas leg.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards