Two-Phase Oil and Gas Separation

This chapter discusses the requirements of good separation design and how various mechanical devices take advantage of the physical forces in the produced stream to achieve good separation Separators are sometimes called “gas scrubbers” when the ratio of gas rate to liquid rate is very high. A “slug catcher,” commonly used in gas gathering pipelines, is a special case of a two-phase gas–liquid separator that is designed to handle large gas capacities and liquid slugs. Some operators use the term “traps” to designate separators that handle flow directly from wells. In any case, they all have the same configuration and are sized in accordance with the same procedure. Separators are classified as “two-phase” if they separate gas from the total liquid stream and “three-phase” if they also separate the liquid stream into its crude oil and water components. Separators are designed and manufactured in horizontal, vertical, spherical, and a variety of other configurations. Each configuration has specific advantages and limitations. Selection is based on obtaining the desired results at the lowest “life-cycle” cost. Many types of separators, such as horizontal, vertical, centrifugal, and venturi, are discussed in this chapter.