PLUNGER LIFT APPARATUS

摘要

A plunger of improved construction for reciprocating in a production string of a gas or oil well to remove fluid from the well. The plunger includes a sleeve having a through passage extending longitudinally from a first end to a second end, the second end forming a seat, a sealing means carried by the sleeve for engaging the inner surface of the production string, a detachable valve member releasably received by the seat to seal the through passage, and a catch positioned to releasably couple the detachable valve member to the sleeve within the seat. The catch retaining the detachable valve member until the detachable valve membe r is impacted at the surface of the well by a trip rod. The improved construction provides fo r the use of a heavier or more dense detachable valve member and a lighter or less dense sleeve tha n previously used in prior plungers, which results in a plunger having an increased efficiency an d a greater cycle frequency.