(57) ABSTRACT A bypass plunger includes a plunger body that includes a head portion
located at one end of the plunger body and a tail portion located at an opposite end of the …

(57) ABSTRACT A bypass plunger combines a unitary or one-piece hollow body-and-valve
cage, retains a dart valve within the valve cage portion of the hollow body using a threaded …

A bypass plunger includes a unibody, or one-piece hollow body and valve cage, retains a
dart valve within the valve cage portion using a threaded retaining nut secured by crimple …

Currently, strong demand for energy and uncertain sup plies have created interest in tapping
unconventional reser voirs. Reservoirs with low permeability are difficult to recover using …

A barrier valve has an equalizing feature for the ball or plug when in the closed position
before it is opened. A hydraulic open and a close line are connected to a housing so that …

A method for locking an internally threaded end piece such as a head piece, a tail piece, an
end or sealing nut to a mandrel for a down hole tool to obviate the need for pins, set screws …

A bypass plunger combines a unitary or one-piece hollow body-and-valve cage, retains a
dart valve within the valve cage portion of the hollow body using a threaded retaining nut …

Embodiments of well plunger systems, assemblies, and apparatuses are described. In an
embodiment, the apparatus includes a body having a first open end, a second open end …

A pressure equalizing system allows flow past an upper seal on a movable member
downhole that in turn allows pressure to be delivered from uphole into what had previously …

US PATENT DOCUMENTS pressure raised in the ball from pressure application at the
surface. Removal of the applied pressure reseats the check 3,273,649 A* 9. 1966 …