Abstract: A submersible pump system may include a perforated casing lining a wellbore adjacent to a first formation and a second formation. Additionally, a production tubing may be hanging in the wellbore to extend past the first formation and into the second formation to form a fluid conduit from a surface to the second formation. Further, an electrical submersible pump may be coupled to the production tubing and be oriented upside-down to have one or more fluid intakes at an upper end of the electrical submersible pump and one or more fluid outlets at a lower end of the electrical submersible pump. The electrical submersible pump may be positioned downhole in the wellbore between the first formation and the second formation. The upside-down electrical submersible pump may be configured to extract fluid from the first formation and inject the extracted fluid into the second formation with the production tubing.

Abstract: A downhole tool actuator includes a housing defining an axial bore and a first port extending radially from the axial bore, as well as a piston disposed and movable within the axial bore of the housing. The piston includes a receptacle wall, a shaft extending axially from the receptacle wall, and a contact member extending across the shaft. The receptacle wall defines a chamber and a second port extending radially from the chamber. The contact member is positioned outside of the housing and is configured to engage a downhole tool.

Abstract: A system includes a cable with a core material, an intermediate layer surrounding the core material, a retention assembly located around the core material and configured to compress the core material and restrict the core material from moving in the cable, and an outer metallic tubular surrounding the intermediate layer. Further an electrical device is coupleable to the cable.

Abstract: A downhole pumping apparatus comprising a positive displacement rotary gear pump (RGP), driven by a rotating rod string or a submersible electric motor.

Abstract: The present invention relates to an annular barrier system for completing a well with a well tubular metal structure, comprising the well tubular metal structure and a first annular barrier and a second annular barrier, each annular barrier comprising a tubular metal part having a bore and mounted as part of the well tubular metal structure, an expandable metal sleeve surrounding the tubular metal part, each end of the expandable metal sleeve being connected with the tubular metal part, and an annular space between the expandable metal sleeve and the tubular metal part, each annular barrier being introduced and set in the well to abut a wall of the well, providing a confined space having a confined pressure Pc between the wall, part of the well tubular metal structure, the first annular barrier and the second annular barrier, so that the first annular barrier isolates the confined space from a first annulus having a first pressure, and the second annular barrier isolates the confined space from a second annul

Abstract: An anchor setting system having redundant setting methodologies including a housing having an internal chamber. The housing has an outer surface, an inner surface, a first end, and a second end. A slip is shiftably mounted to the outer surface of the housing. A piston assembly including a piston element is arranged in the housing. The piston element includes a conduit and is shiftably mounted in the internal chamber. An activator is mounted to the piston assembly. The activator selectively shifts the slip axially along the housing in response to movement of the piston element.

Abstract: The present disclosure relates to biocide compositions, formulations and methods for using formulations. In particular the present disclosure relates to biocide compositions and their use in effecting biocidal activity in subterranean oil and gas wells being drilled, completed, worked over or produced.

Abstract: A system for operating a downhole system in a wellbore having pressure inlet ports formed in the production tubing, the one or more pressure inlet ports extending through the production tubing between the annular area and the outer surface of the conduit, the one or more pressure inlet ports being situated below a first top sealing device relative to the conduit. The system includes an annular pressure control valve coupled to a metal conduit below the one or more pressure inlet ports in the wellbore, the annular pressure control valve being configurable in an open position and in a closed position, where the annular pressure control valve transitions between the closed position and the open position responsive to the annular pressure. The system includes a second bottom sealing device coupled to a bottom portion of the conduit below the annular pressure control valve.

Abstract: An eccentric pipe-in-pipe downhole gas separator apparatus for separation of gas from liquid in a downhole well. The separator apparatus includes an outer tube having an inner diameter and an inner tube having an outer diameter smaller than the inner diameter of the outer tube. The inner tube is eccentric to the outer tube wherein a conduit having a crescent shaped cross-section is formed between the inner diameter of the outer tube and the outer diameter of the inner tube.

Abstract: An example system for a well includes a tubing string including spoolable, flexible, coiled tubing to transport fluids within the well; a packer associated with the tubing string to provide an annular seal to a section of a wellbore of the well; a power generator associated with the tubing string to generate power for the system based on fluid flow within the well; a wireless communication device associated with the tubing string to exchange information with one or more components of the system; one or more sensors associated with the tubing string to sense one or more environmental conditions in the well; one or more processing devices associated with the tubing string to generate at least some of the information based on the one or more environmental conditions; and one or more inflow control valves to control a rate of fluid flow into the system.

Abstract: The present invention relates to an annular barrier system for completing a well with a well tubular metal structure, comprising the well tubular metal structure comprising a first annular barrier and a second annular barrier, each annular barrier being introduced and set in the well to abut a wall of the well providing a confined space having a confined pressure between the wall, part of the well tubular metal structure, the first annular barrier and the second annular barrier, so that the first annular barrier isolates the confined space from a first annulus having a first pressure and the second annular barrier isolates the confined space from a second annulus having a second pressure, wherein the annular barrier system comprises a pressure equalising unit having a first position in which the first annulus is in fluid communication with the confined space and a second position in which the second annulus is in fluid communication with the confined space, in the first position the second pressure is higher

Abstract: A wellbore completion is configured for multiple forms of artificial lift. A downhole assembly on production tubing defines a production port communicating a throughbore with the wellbore annulus. A bypass, such as a snorkel or riser tube, on the assembly also communicates the throughbore between the packer and the production port with the annulus. A packer on the assembly seals in the annulus downhole of the production port and bypass. The assembly can then be configured for any selected artificial lift. To do this, at least one isolation (a sleeve insert, a sliding sleeve, a check valve, or a rupture disk) selectively prevents/allows communication via one or both of the production port and the bypass as needed. Additionally, removable lift equipment, including jet pump, gas lift valve, plunger assembly, rod pump, piston pump, or standing valve, is selectively inserted into the assembly's throughbore as needed.

Abstract: A system for producing hydrocarbons from a subterranean well includes an electrical submersible pump assembly with a motor, a seal section, and a pump. A packer assembly with a mechanical valve is retrievable with the electrical submersible pump assembly and is a primary high pressure mechanical barrier. A shroud fully encapsulates the electrical submersible pump assembly. An annular seal assembly seals around an outer diameter of the shroud, the shroud and the annular seal assembly together being a secondary high pressure mechanical barrier.

Abstract: An example method of forming a well includes identifying a lost circulation zone in a wellbore, where the lost circulation zone includes a fracture in a formation adjacent to the wellbore; arranging an inflatable in a vicinity of the lost circulation zone; forcing slurry into the inflatable to cause at least part of the inflatable containing the slurry to expand into the fracture; allowing the slurry to set for a period of time to produce a solid; and drilling through the solid in the inflatable in the wellbore, leaving the solid in the fracture.

Abstract: Provided in one aspect is a new tool and methodology to work, in a single-trip system, and create conduits through the casing or tubing to access the annuli, circulate out the annuli contents, accurately deliver the cement required to create the subsequent barrier. The tool and system provided by this aspect provide a cost effective way of plugging an oil and gas well in a single trip without the need to remove in-place production casing.

Abstract: A downhole vibratory tool for placement in drillstrings which creates vibration in the drillstring while drilling. A rotary drive rotates in response to fluid flow through it, rotating a rotor having a lower end engaging an upper end of a mandrel. The mandrel is held in a main body such that it is rotationally locked with respect to the main body, but can move longitudinally within a restricted range. The lower end of the rotor and the upper end of the mandrel have interfacing surfaces. Rotation of the rotor and interaction of the interfacing surfaces creates a back-and-forth movement of the mandrel with respect to the rest of the tool, creating the desired vibratory motion.

Abstract: A liquid treatment system includes: a filter casing including a structural wall, a first screen formed though the structural wall, and a second screen formed though the structural wall; and a liquid treatment cartridge configured for placement in the filter casing between the first and second screens. The liquid treatment cartridge includes a cartridge casing having an upper end and a lower end, and an inflatable seal surrounding the cartridge casing at an intermediary position between the upper end and lower end. A method of servicing a groundwater treatment installation includes: vertically displacing a liquid treatment cartridge within a filter casing having a structural wall, a first screen formed though the structural wall, and a second screen formed though the structural wall.

Abstract: A method for providing well safety control in a remedial electronic submersible pump (ESP) application including a making up an electric submersible pump (ESP) on a conduit with a primary well control capability; running the foregoing through a preexisting SCSSV.

Abstract: A method of automatically washing a well casing of a progressing cavity (PC) pump system. The method includes disabling, via a controller, a normal speed control of a progressing cavity (PC) pump of the PC pump system, and closing, via the controller, a gas flow valve to stop upward fluid flow in an annulus of the well casing. The method further includes opening a wash valve to allow fluid from the wash fluid source into the well casing. Upon wash fluid accumulation within the annulus, the method further includes increasing the speed of the pump to begin flushing the well casing, and closing the wash valve.

Abstract: Drilling flow control tools may include a tool body having a central bore and bypass ports that allow flow of fluid to an outer surface of the tool body. The drilling flow control tool may also include a control sleeve within the central bore. The control sleeve may restrict fluid flow through the bypass ports when in an inactive state and allow the fluid flow through the bypass ports when in an active state. The drilling flow control tool may further include a release subassembly movably coupled to the tool body. Packer cups coupled to the tool body can act as packoff devices that control passage of fluid along the outer diameter of the tool body. Using the packer cups and control sleeve, fluid flow may be circulated within an inner annulus of a wellbore, an outer annulus of a wellbore, or both.

Abstract: A system and method of producing fluid from a wellbore, and that separates water from the fluid. The system includes an electrical submersible pumping system with a pump having impellers and diffusers, and a separation system at a discharge end of the pump. The separation system includes a helical flow path and separation chamber downstream of the path. Directing the fluid through the helical flow path centrifugally separates the water from the fluid. Thus when the fluid flows into the separation chamber from the helical flow path, the water migrates to the outer radius of the separation chamber. The separated water flows through ports on the outer sidewall of the separation chamber, and the lower density portion of the fluid flows through a port proximate a middle portion of the separation chamber.

Abstract: A method of mitigating undesired pressure variations in a wellbore due to movement of a well tool string in a well can include selectively decreasing and increasing fluid communication between sections of a wellbore on opposite sides of at least one well tool in the well tool string, the fluid communication being increased in response to detecting a threshold movement of the well tool string relative to the wellbore. A well tool string can include a well tool connected in the well tool string, and having an enlarged outer dimension relative to adjacent sections of the well tool string, a flow passage extending between the well tool's opposite ends, a sensor, and at least one flow control device which selectively permits and prevents fluid communication between the opposite ends via the flow passage, in response to an output of the sensor indicative of movement of the well tool string.

Abstract: A submersible reciprocating oil well pump unit, including: a control cabinet, a rotary type submersible motor, a borehole torque reversing device, a borehole reciprocating pump, a submersible cable, a first joint, a second joint, and an oil pipe. The control cabinet is disposed at wellhead and connected to the rotary type submersible motor submerged in a downhole sleeve via the submersible cable. The motor shaft is connected to one end of the screw rod of the screw pair of the borehole torque reversing device via the first joint. One end of the driving rod is connected to a push-pull rod of the borehole reciprocating pump via the second joint. The oil outlet is connected to the oil pipe. The borehole torque reversing device is adapted to drive the control cabinet to commutate automatically according to set loading values.

Abstract: A retrievable string is positioned in a stator of a completion string installed in a well. The retrievable string includes a rotating portion and a non-rotating portion. The rotating portion includes a rotor and an impeller coupled to the rotor. The non-rotating portion includes a coupling part. The coupling part is coupled to a corresponding coupling part of the completion string.

Abstract: A down-hole packer is provided for positioning in a wellbore to establish a seal with a surrounding surface. The packer includes a sealing element that is responsive to compression by a setting piston to radially expand into the wellbore. An actuator is provided to longitudinally move the setting piston in response to a telemetry signal received by the down-hole packer. The actuator can include a hydraulic pump, an electromechanical motor or valves operable to control hydraulic energy to apply a down-hole force to the setting piston.

Abstract: A method and system for treating a hydrocarbon-bearing reservoir with a DOWS system includes forming a first and a second DOWS system wells that fluidly communicate with both a first and second hydrocarbon-bearing formation. The first well has an upflowing DOWS unit and the second well has a downflowing DOWS unit. The DOWS units separate production fluid into a water-rich fluid and a hydrocarbon-rich fluid that passes to the surface. Both wells have an injection zone and a production zone. The DOWS system is operated such that water-rich fluid from the first DOWS well is introduced into the first hydrocarbon-bearing formation, water-rich fluid from the second DOWS well is introduced into the second hydrocarbon-bearing formation, production fluid from the second hydrocarbon-bearing formation is introduced into the first DOWS well, and production fluid from the first hydrocarbon-bearing formation is introduced into the second DOWS well.

Abstract: A seat forming apparatus for use in a downhole tool comprising a driving member and a seating restriction. The driving member and the seating restriction are mechanically disposed within an outer housing of the downhole tool. When the driving member drives into the seating restriction, the seating restriction or the driving member bend or buckle inwards to form a seat in the downhole tool. The inner diameter of the seat is configured to allow a restriction element to be seated in the seat.

Abstract: Certain aspects are directed to a testable isolation packer that sets and provides the ability to test upper and lower packer elements. In one aspect, the testable isolation packer includes at least two packer elements, a packer element setting system, a bypass system, and a testing subassembly. The testing subassembly generally includes a moveable element with an outer port and a sealing element, an inner mandrel with an inner port, and a shear mechanism to cause travel of the moveable element close the bypass system and to open the testing subassembly.

Abstract: A method of disposing of fluids produced from a wellbore extending into a subsurface formation, the subsurface formation having a production zone and a disposal zone, at least a portion of the wellbore lined with a string of production casing. The method includes placing a wellbore tubular conduit within the casing; placing a pump in fluid communication with the wellbore tubular conduit, the pump having an inlet and a discharge, the inlet in fluid communication with a source of produced fluids; and injecting the produced fluids through a plurality of perforations positioned about the casing into a disposal zone of the subsurface formation. A system for disposing of fluids produced from a wellbore extending into a subsurface formation is also provided.

Abstract: A downhole occluder for oil wells includes a sealing socket and a positioning flange with sealing surfaces set up inside an oil pipe. An oil sucker rod pump is installed inside the tubular column which mounts on top of the sealing socket. A sealing surface of a sealing flange on the rod pump mounts with a sealing surface of the sealing socket on the tubular column. Outer oil inlet borings are placed at the wall of oil tubular column underneath the positioning flange. An inner pipe is installed inside this section of tubular column. Place inner oil inlet borings on the inner pipe wall corresponding to outer oil inlet borings on the tubular column. Sealing grooves are placed underneath the inner oil inlet borings on the inner pipe wall. Sealing rings are placed in the sealing grooves to seal the inner wall of tubular column.

Abstract: A downhole vibratory tool for placement in drillstrings is disclosed. The downhole vibratory tool creates vibrations in the drillstring while drilling. A rotary drive rotates in response to fluid flow through it, rotating a rotor having a lower end engaging an upper end of a mandrel. The mandrel is held in a main body such that it is rotationally locked with respect to the main body, but can move longitudinally within a restricted range. The lower end of the rotor and the upper end of the mandrel have interfacing surfaces. Rotation of the rotor and interaction of the interfacing surfaces creates a back-and-forth movement of the mandrel with respect to the rest of the tool, creating the desired vibratory motion.

Abstract: A gas separator assembly generates an artificial sump in a production casing receiving a production tubing string with a downhole pump at the bottom end thereof. The assembly includes an inner casing in series with the production casing of the well and an outer casing supported externally of the inner casing. First and second ports at opposing top and bottom ends of the outer casing communicate from a primary passage in the inner casing to a secondary passage between the inner and outer casings. A barrier supported in the primary passage between the first and second ports diverts flow through the secondary passage and effectively defines the sump area in the primary passage between an inlet of the downhole pump adjacent the barrier and the first port thereabove.

Abstract: A fluid production system for downhole fluid purification includes a filtering assembly to be positioned within a wellbore. The filtering assembly has a fluid filter and a first pump closely-coupled to the filter. In addition, the system includes an extension shaft extending from the first pump to a source of rotational power positioned adjacent the surface of the earth.

Abstract: An apparatus (100) for operation in a tubular channel (199), the apparatus comprising a first part and a second part connected to the first part, wherein the second part comprises a first electronic device adapted to generate a data signal and a first communications device for wirelessly transmitting the generated data signal via a wireless communications channel, wherein the first part comprises a second communications device for wirelessly receiving the transmitted data signal via said radio-frequency communications channel.

Abstract: A mud motor for use in a wellbore may include a stator and rotor. The tolerance between the stator and rotor may be varied along the length of the mud motor to, for example, reduce wear of the stator at predetermined locations. The tolerance may range from an interference fit to a clearance fit. The tolerance may vary multiple times across the length of the mud motor.

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: An annular barrier system for proving a testable annular barrier arranged between a first metal casing or borehole and a second metal casing. The annular barrier system has a first annular barrier and a second annular barrier, each barrier including a tubular part made of metal extending in a longitudinal direction for mounting as part of the second metal casing, an expandable metal sleeve surrounding and connected with the tubular part and defining an annular barrier space, and a first fluid passage in the tubular part for letting fluid into the annular barrier space to expand the sleeve. The annular barrier system further includes a sensor, and when the expandable sleeves are expanded to abut the first metal casing or borehole, a first annular space is at least partly defined between the annular barriers. The sensor is arranged to determine a condition of the annular space in order to test the isolation ability of at least one of the annular barriers.

Abstract: A downhole tool for use in a wellbore tubular string comprises a housing having a bore therethrough forming part of a fluid flowpath through the wellbore tubular string, a sliding member operable to slide with respect to the housing, a plurality of magnetic pins, and a corresponding plurality of springs. A sliding line is formed by interfacing surfaces of the sliding member and the housing, and the plurality of pins comprise a locked position and an unlocked position whereby in the locked position at least one pin spans the sliding line to prevent the sliding member from sliding with respect to the housing and in the unlocked position no pins span the sliding line. The plurality of springs biases the pins towards the locked position.

Abstract: An intrawell fluid injection system is operably positionable in a well having a production zone that is in fluid isolation from a discharge zone. The system includes an electric submersible pump assembly having an electric motor and a fluid pump that is operably associated with the electric motor. The fluid pump has a fluid intake operably positionable in fluid communication with the production zone. The fluid pump is operable to pump formation fluid from the production zone in a first axial direction. The system also includes a bypass assembly that is in downstream fluid communication with the electric submersible pump assembly. The bypass assembly is operable to transport formation fluid from the electric submersible pump assembly in a second axial direction that is opposite the first axial direction. The bypass assembly has a fluid discharge operably positionable in fluid communication with the discharge zone.

Abstract: Provided is a process including: receiving a tank-nearly-full message indicating that a tank at an oil or gas related facility is or will be ready for a truck to unload and transport fluid accumulating in the tank; in response to the tank-nearly-full message, creating a tank-run record; sending a description of the tank-run to a mobile device of a driver of an oilfield truck; receiving, from the mobile device of the driver of the oilfield truck, a tank-run claimed message indicating that the driver will drive to the oil or gas related facility and transport at least some of the fluid accumulating in the tank; and after the tank-run claimed message, performing steps including: confirming that the tank-run has not yet been claimed; after the confirmation, designating the tank-run as claimed by the driver; and sending confirmation to the mobile device of the driver.

Abstract: A distributed artificial lift system is configured for use in a wellbore that includes a vertical section and at least one lateral section connected to the vertical section. The distributed artificial lift system includes a first remote assembly positioned within the first lateral section. The first remote assembly includes an equipment deployment vehicle and cargo selected from the group consisting of electric remote pumping units, tubing, tubing connectors, tubing adaptors, sensor packages, gas separators, perforating tools, injection pumps and other downhole components. The first remote assembly is optionally self-propelled and remotely-controlled.

Abstract: Methods and systems of treating hydrocarbon containing formations are described herein. A system for treating a subterranean hydrocarbon containing formation includes a wellbore, and one or more packers positioned in the wellbore. At least one of the packers allows fluid to be injected in a subterranean hydrocarbon containing formation while allowing fluid to be produced from the wellbore.

Abstract: Certain aspects and embodiments of the present invention are directed to a dual closure system disposed within a wellbore and capable of preventing the production of fluids from a fluid-producing formation to the surface. The dual closure system can include a passive closure mechanism and a subsurface safety valve coupled to an electric submersible pump positioned within a passageway defined by the tubing string. The passive closure mechanism and the subsurface safety valve can prevent production of fluid in the absence of the subsurface safety valve. The subsurface safety valve can be positioned within a passageway defined by a tubing string such that the subsurface safety valve can apply force to the passive closure mechanism. The force applied to the passive closure mechanism can maintain the passive closure mechanism in an open position, allowing movement of fluid to the surface in the presence of the active closure mechanism.

Abstract: The present invention relates to an annular barrier (1) to be expanded in an annulus (2) between a well tubular structure and an inside wall (4) of a borehole (5) downhole, comprising a tubular part for mounting as part of the well tubular structure, said tubular part (6) having a longitudinal axis; an expandable sleeve (7) surrounding the tubular part and having an outer face (8), each end (9, 10) of the expandable sleeve being fastened to the tubular part by means of a connection part (12), where one of the connection parts is a sliding connection part sliding in relation to the tubular part when the expandable sleeve is expanded; an annular barrier space (13) between the tubular part and the expandable sleeve; an aperture (11) in the tubular part for letting fluid into the annular barrier space to expand the sleeve; and an activatable shut-off valve (14) having an open and a closed position and arranged in the aperture, wherein the annular barrier further comprises a detection device (20) for detecting whe

Abstract: A device and method of handling a plug in a tubing hanger includes a pressure actuated sequence valve that has multiple outlets. Hydraulic fluid from a remotely operated vehicle (ROV) provides hydraulic fluid that selectively flows through the valve for operating a tool that handles the plug. The valve outlets are ported to separate lines for operating different functions of the tool. Flow to a specific outlet occurs by sequencing the valve to a corresponding position, where the valve is sequenced by changing pressure of the hydraulic fluid. The sequence valve is disposed in a piston that is axially movable within the tool. A stroking rod attaches to the piston, and is actuated by diverting flow to sides of the piston.

Abstract: A subterranean pump is delivered on coiled tubing with power and control cables running inside. The pump suction has a tubular inlet that seals in a polished bore in the surrounding tubular. A diverter opens a lateral port and closes entry to the pump suction when the pump is not running and the formation pressure is high enough to bring production to the surface. This configuration prevents the pump from turning while the formation pressure allows production to the surface. If the pump is started it reduces pressure ahead of a movable plug to draw it toward the pump against a spring bias. The lateral ports close and an inline flow path opens to allow the pump to draw through the diverter and discharge into the annular space around the coiled tubing on the way to the surface.

Abstract: A housing for a downhole tool, having a fluid vent assembly comprising a port passing through the wall of the housing to transmit fluid through the port when the port is open, a sealing device to seal the port, and a cutting device to disrupt the sealing device and permit transmission of fluid through the port. The cutting device is driven axially through the sealing device without relative rotation between the two. The cutting device has an asymmetric blade to cut a coupon from the sealing device by a gradual and progressive disruption of the closure, typically cutting through only a portion the closure device, so that the coupon cut from the closure device remains attached to the closure device when the closure device is ruptured to open the seal. Typically the downhole tool comprises a downhole pump, and the housing comprises the shroud of the pump.

Abstract: A pack-off device, including a body having a first feedthrough and a second feedthrough formed therein. A projection extends from the body and is operatively arranged to engage a restriction of an adjacent structure. At least one seal element is arranged with the body for sealing the device against the adjacent structure when the projection is engaged with the restriction. A method of arranging and operating a completion system is also included.

Abstract: A system and method for lifting reservoir fluids from reservoir to surface through a wellbore having a first tubing string extending through a packer in a wellbore casing. The system includes a bi-flow connector in the first tubing string, a second tubing string in the first tubing string below the bi-flow connector, and a third tubing string in the first tubing string above and connected with the bi-flow connector. A fluid displacement device in the third tubing string is configured to move reservoir fluids to the surface. The first tubing string allows pressured gas to move from the surface through the bi-flow connector to commingle with and lift reservoir fluids through annuli defined by the first and second tubing strings and defined by the casing and the first tubing string. The bi-flow connector is configured to allow simultaneous and non-contacting flow of the downward pressured gas and lifted reservoir fluid.

Abstract: An improved 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.