Abstract: A plunger with expandable mating pad elements arrayed circumferentially about the plunger's body sealed to the plunger and biased to expand the plunger assembly's outer circumferential surface toward the inner surface of the tubular within which the plunger assembly is designed to operate. The gaps between the pad elements are minimized by having the adjacent pad elements slidable against each other along two sets of surfaces along essentially the length of the interface between adjacent pad elements, one surface set being approximately axial to the plunger and the other set being approximately radial to the plunger's longitudinal axis, and in this way reducing the available pathway in the gap between adjacent pad elements for fluid to bypass the plunger assembly.

Abstract: 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.

Abstract: 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.