The produced fluid from oil formation consists of a mixture of oil, gas, free water and water in oil emulsion. Oil processing involves separating the oil from other fluids (gas and water) for the following reasons:
- Crude oil must be free of gas so that storage tanks will not be a fire hazard due to escaping gas.
- Liquid must be removed from a gas stream to prevent it from accumulating in low sections of a pipeline and restricting the flow of gas.
- The water content in the oil must be low in order to maximize its commercial value.
Separators are used to separate the liquids from the gases at any pressure and temperature and to prevent or eliminate liquid entrainment in the gas stream leaving the separator.
Types of Separators
Separators are classified according to the configuration, number of phases separated, and the service. There are three types of separators, Vertical, Horizontal, and Spherical.
Vertical separators, perform a high efficiency demisting. They combine the advantages of the best inlet device, the dish deflector, with the mistmat and a demister pad into one vessel.
The oil and gas mixture enters through the inlet nozzle and hits an angle baffle (schopentoter) where the direction of flow is changed. Here the heavier liquids fall to the bottom of the separator while the gas and spray liquid rises.
This wet gas passes through the mist extractor (where the remaining small liquid particles are removed) and then along the upper part of the separator to reach the gas outlet.
Two and three phase separators
Separators are classified as “two-phase” if they separate gas from the total liquid stream and “three-phase” if they separate gas from the liquid stream and then liquid into crude oil and water components. Bulk separator is two phase separator. Test separator is three phase separator.