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 secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions. Combinations of these features provide enhanced performance, durability and reliability at reduced manufacturing cost, due primarily to the simplicity of its design.

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 secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions. Combinations of these features provide enhanced performance, durability and reliability at reduced manufacturing cost, due primarily to the simplicity of its design.

A plunger having a generally hollow interior between an open upper end of the plunger and a closed bottom end of the plunger. One or more orifices extend through a sidewall of the plunger near the closed bottom surface. The orifices fluidly connect the hollow interior of the plunger with the tubing below the plunger when the plunger is in use. The orifices allow for a transfer of gas from the well bottom into the liquid load above the plunger during plunger ascent. The orifices also allow liquids to pass through the plunger during plunger descent.

A plunger having a generally hollow interior between an open upper end of the plunger and a closed bottom end of the plunger. One or more orifices extend through a sidewall of the plunger near the closed bottom surface. The orifices fluidly connect the hollow interior of the plunger with the tubing below the plunger when the plunger is in use. The orifices allow for a transfer of gas from the well bottom into the liquid load above the plunger during plunger ascent. The orifices also allow liquids to pass through the plunger during plunger descent.

A lubricator is provided which has a unitized body with at least one port in communication with the body's bore and its outer surface, to which port(s) connectors with different outer fittings for further connection to other equipment may be attached and sealed, and later detached and replaced with other connectors. The connectors may have different outer fittings or may be a plug or valve. This allows the connection of a single port to external equipment to be changed and the fitting for that external equipment's connection to be altered, without having to disconnect the lubricator from its well-head and stem or any of the lubricator's other connections.

A lubricator is provided which has a unitized body with at least one port in communication with the body's bore and its outer surface, to which port(s) connectors with different outer fittings for further connection to other equipment may be attached and sealed, and later detached and replaced with other connectors. The connectors may have different outer fittings or may be a plug or valve. This allows the connection of a single port to external equipment to be changed and the fitting for that external equipment's connection to be altered, without having to disconnect the lubricator from its well-head and stem or any of the lubricator's other connections.

A plunger for oil and gas wells includes a shaft and a sleeve carried by the shaft. The sleeve defines a passageway located between a surface of the sleeve and a portion of the shaft, and the sleeve is longitudinally translatable relative to the shaft from a first configuration to a second configuration and vice versa. In the first configuration the plunger inhibits fluid flow through the passageway, and in the second configuration the plunger permits fluid flow through the passageway. The plunger further includes a force dissipating element interposed between the shaft and the sleeve. The force dissipating element at least partially dissipates forces caused by at least one of (1) the sleeve stopping relative to the shaft after translating from the first configuration to the second configuration; and (2) the sleeve stopping relative to the shaft after translating from the second configuration to the first configuration.

An unloading plunger having an internal chamber to hold compressed gas and a timer-operated valve to release the compressed gas through a gas jetting port as a jetting force for ascent of the unloading plunger in a wellbore to unload liquid from a well. The ascending of the unloading plunger may be via a combined motive force of wellbore pressure provided by formation pressure plus the jetting force provided by ejecting the compressed gas from the unloading plunger.

An unloading plunger having an internal chamber to hold compressed gas and a timer-operated valve to release the compressed gas through a gas jetting port as a jetting force for ascent of the unloading plunger in a wellbore to unload liquid from a well. The ascending of the unloading plunger may be via a combined motive force of wellbore pressure provided by formation pressure plus the jetting force provided by ejecting the compressed gas from the unloading plunger.

An unloading plunger having a chamber for compressed gas and a method for unloading liquid from a wellbore via ascending of the unloading plunger including ascending via formation pressure the unloading plunger from the bottom portion of the wellbore to a rest position at a wellhead and releasing compressed gas from the chamber into the wellbore during the ascending to decrease hydrostatic pressure of liquid in the wellbore above the unloading plunger.