1. n. [Production Facilities]

An operation in which the well stream is passed through two or more separators that are arranged in series. The first separator is called first-stage separator, the second separator is called second-stage separator and additional separators are named according to their position in the series. The operating pressures are sequentially reduced, so the highest pressure is found at the first separator and the lowest pressure at the final separator. The objective of stage separation is to maximize the hydrocarbon liquid recovery and to provide maximum stabilization to the resultant phases (liquid and gas) leaving the final separator. Stabilization means that considerable amounts of gas or liquid will not evolve from the final liquid and gas phases, respectively, in places such as stock tanks or gas pipelines. Additionally, stage separation reduces the horsepower required by a compressor, since the gas is fed at higher pressures.