Plunger to Form a Liquid Ring to Seal Against Gas Bypass

Abstract

A plunger for moving up and down in a tubing string in a plunger lift system includes an elongated body having an upper end, a lower end and a longitudinal axis, an upper passage extending axially in the body from a top opening located toward the upper end, and a liquid cross-hole extending from the upper passage to an outer circumferential surface of the body. The upper passage is closed to the exterior of the lower end at least when the plunger is located at or proximate to the bottom end of the tubing string. In some embodiments the upper passage extends from the top opening to a terminal end or position located inside the body and not in communication with the exterior of the lower end. The upper passage may extend from the top opening to a bottom opening toward the lower end and include a valve element to selective close the bottom opening.

Dependencies are inferred from the claim text.