Patent ID: 6200103
Filing Date: 2001-03-13
Classification: E21B,F04B

Abstract:
A plunger for movement up and down in a tubing string in a plunger lift system for an oil and gas well comprising:an elongated plunger body having a peripheral surface and a space between the tubing string and said peripheral surface,the tubing string and said peripheral surface defining a flow passage along the entire length of said plunger body along which an upflowing gas moves,said plunger body having a plurality of longitudinally spaced circumferential grooves in said peripheral surface,each said groove being defined by a recessed surface connected at a lower extent by a convex curved surface to said peripheral surface and connected at an upper extent at a corner to said peripheral surface to provide laminar entry of the upflowing gas into said groove and turbulent exit of the upflowing gas out of said groove.