1. n. [Production Testing]

A perforated tubular attached to the subsurface sucker-rod pump that controls the entrance of gas. Since it is the only way for formation fluid to enter the pump, its use increases the efficiency of the subsurface sucker-rod pump. It also helps to prevent the phenomenon called gas lock. A gas anchor is similar to a bottomhole gas separator.

Synonyms: bottomhole gas separator

See related terms: formation fluid,  gas lock,  rod pump,  sucker rod