Plunger with novel sealing

摘要

A plunger for use in downhole tubulars in wells which produce fluids and/or gases under variable pressure. The plunger is slidingly engageable within the tubulars and capable of movement up and down the tubulars, and has a jacket comprised of segments mounted about a core which have sealing, holding, and lifting capabilities. An inner turbulent or labyrinth-type seal is accomplished by circumferential grooves on the core and/or fingers which project inwardly from the underside of the segments. When the pressure inside the tubulars above the plunger is reduced, the plunger and fluids move upwardly to the surface.