Abstract: Disclosed embodiments relate to inflatable packer elements, which may be configured to dynamically adjust the axial position of the seal element. The seal element may include an inflatable bladder having a thin-walled skin, which may be radially expanded into sealing position by inflation of the bladder. Embodiments may be configured to dynamically alter the configuration of the bladder by axial movement of the bladder in order to provide additional radial expansion of the bladder. For example, one or both of the top and bottom sides of the seal element bladder may be configured to dynamically translate axially towards the other of the top and bottom sides, which may provide additional material of the thin-walled skin of the bladder capable of expanding radially outward upon inflation. Systems and methods of using and making such packer devices are also disclosed.

Abstract: An insertion tool assembly includes a lubricator and a tubular adapter. The tubular adapter includes a main body with a central bore therethrough. A top end of the adapter can be attached to the lubricator and the bottom end attached to a crown top of a wellhead. The tubular adapter also includes a kill fluid port disposed through a side-wall of the main body. The insertion tool assembly is configured such that, when the BPV is attached to the distal end of the rod and the bottom end of the tubular adapter is attached to the crown top, the BPV can pass through the tubular adapter and into the wellhead through the crown top as the rod is extended from the lubricator, and a kill fluid injected into the kill fluid port can flow through the crown top into the well.

Abstract: A system performs inner string cement operations in a wellbore. The system includes a stab-in stinger connected to a distal end of a drill string and a stab-in float shoe connected to a distal end of a casing. The stab-in float shoe includes a first check valve and a plug type rupture disc. The first check valve includes instructions configured to prevent a reverse flow of cement mixture. The plug type rupture disc is house between the first check valve and an outlet of the stab-in float shoe. The plug type rupture disc includes instructions configured to rupture at a predetermined threshold pressure and, once ruptured, permits flow of cement mixture from the annulus into the stab-in float shoe. A related method includes: enabling a stab-in stinger to stab-into a stab-in float shoe, starting the cementing operation and rupturing the plug-pe rupture discs at predetermined pressure.

Abstract: The present disclosure provides a two-stroke pumping method and oil production device, and relates to the technical field of oil production. The oil production device comprises a pump body, wherein the oil production device further comprises a central tube of a hollow structure, and the central tube is partially located in the pump body and coaxially arranged with the pump body; a traveling valve and a standing valve are arranged on the left side and the right side of the outer wall of the central tube respectively, and the traveling valve is arranged between the pump body and the central tube; the standing valve is located outside the pump body; the traveling valve and the standing valve are matched with the pump body and the central tube to form an oil pumping space; and an oil pumping assembly is further arranged in the oil pumping space.

Abstract: A tubing hanger includes a hanger connection profile positioned along a borehole of the tubing hanger and a first landing profile positioned along the borehole and above the hanger connection profile. The first landing profile includes first threads including a first thread feature configured to secure a first check valve to the tubing hanger for isolating a production tubing. The tubing hanger further includes a second landing profile positioned along the borehole and above the first landing profile, the second landing profile including second threads including a second thread feature. The second thread feature is larger than the first thread feature and is configured to secure a second check valve to the tubing hanger for further isolating the production tubing.

Abstract: An insert valve installed, at least partially, in a safety valve that includes a flow port disposed on an exterior of the insert valve, a poppet configured to control a fluid flow through the flow port, a piston rod, disposed uphole from the poppet, configured to move the poppet past at least part of the flow port, where the piston rod includes an upper exposed piston area exposed to an internal volume of the insert valve, and a lower exposed piston area exposed to the internal volume of the insert valve, and a hydraulic control port configured to control movement of the piston rod.

Abstract: The present description relates to processes and systems for asynchronous frac-to-frac operations for recovering hydro-carbons. The processes can include the use of injection-only and production-only valves that include a housing and at least one sleeve as well as flow restriction components, check valves, or other features. The flow restriction component can be a tortuous path provided in the sleeve. The check valves can be integrated into the sleeve or into the housing of the valve. Various different types of valve assemblies can be used and integrated with flow restriction components and/or check valves.

Abstract: A system and a method for reduction or elimination of environmentally harmful or “greenhouse” gases in situations in which gaseous hydrocarbons are flared or vented from an oil and gas well are disclosed. The system configures to inject a chemically reactive, or dispersive, or reactive and dispersive atomized mist into a gas flow line leading to a flare stack. The mist reacts with the gas in the flow line to convert methane to hydrogen and carbon monoxide and to reduce other harmful gases, facilitating a clean-burning, compact flare of blue color due to the presence of primarily hydrogen, some carbon monoxide, and a small amount of residual methane. The hydrogen and carbon monoxide may be captured and stored before reaching the ignition point at the top of the flare stack.

Abstract: Methods and kits for assembling a flow cage assembly are provided. The flow cage assembly may be used in a traveling valve, a standing valve, or a top plunger adapter of a downhole reciprocating pump. In some embodiments, the method comprises assembling a body, a tubular insert, and a retaining element such that the retaining element forms an interference fit with the body and thereby securely retains the tubular insert within the body. Top plunger adapters are also provided, assembled from embodiments of the methods and kits.

Abstract: An electrical submersible pump (ESP) system, comprises a motor rotationally coupled to a pump. The system has at least one of (i) a rotation stop operable to stop transfer of rotation of the pump to the motor when the ESP is switched off and (ii) a flow control valve operable to stop flow through the pump in both flow directions when the ESP is switched off.

Abstract: A pressure bleed-off system. The system includes a fluid bypass line having an inlet and an opposing outlet, wherein the inlet is in fluid communication with a high pressure frac line for a hydraulic fracturing operation. The system also includes a high pressure transducer located proximate the fluid inlet, a first plug valve residing along the fluid bypass line, and a first electric actuator residing on the first plug valve. The actuator is configured to rotate the first plug valve between close and open positions in response to command signals from a controller. The controller, in turn, sends the command signals in response to control signals delivered by an operator, remotely. Preferably, the command signals are wireless signals sent from outside of the red zone. The system may also include a second plug valve along the bypass line.

Abstract: A downhole packer apparatus for establishing a seal in an annulus between the apparatus and a wall of a bore or bore-lining tubing. The apparatus comprises a body and a plurality of sealing elements configured for mounting on the body, each sealing element engages the wall of the bore or bore-lining tubing dividing the annulus into a plurality of annulus portions. A bypass arrangement operatively associated with each of the sealing elements communicates fluid between the respective plurality of annulus portions.

Abstract: A frac plug with a flapper, wherein the flapper is configured to set and unset based on a pressure differential and/or fluid flow associated with the frac plug.

Abstract: Loss circulation material (LCM) and method for treating loss circulation in a wellbore in a subterranean formation, including placing the LCM having a solid body with permeable portions or pores into the wellbore to dispose the LCM at the loss circulation zone, and collecting solids onto the LCM at the loss circulation zone to form a barrier. The LCM may be applied at a loss circulation zone in a hydrocarbon reservoir section of the subterranean formation, and upon subsequent hydrocarbon production the collected solids may be dislodged by the produced hydrocarbon to allow for hydrocarbon production through the permeable portions or pores of the disposed LCM.

Abstract: A well sealing tool may include a hydraulic setting mechanism wherein a setting chamber is isolated after setting a sealing element in engagement with a wellbore. In one example, a setting mechanism includes a setting chamber housing positionable about a mandrel to define at least a portion of a setting chamber between the mandrel and the setting chamber housing. A setting port fluidically couples a through bore of the mandrel with the setting chamber. A valve element is biased toward a closed position within the setting port. A guide sleeve is disposed about the mandrel in a first position that props the valve element to an open position. The guide sleeve is moveable to a second position in response to a threshold pressure applied to the setting chamber to release the valve element to the closed position.

Abstract: A standing valve assembly comprises a flow cage, a ball seat, and a valve ball. The flow cage includes a cage body defining an axial fluid passage therethrough, and a bridge extending across the fluid passage. The cage body and the bridge collectively define a plurality of openings to the fluid passage. The valve ball is received between the bridge and the ball seat and is axially movable within the flow cage. The bridge has an upper face and defines at least one guide ramp in the upper face. Each guide ramp extends at a downward angle to a respective one of the plurality of openings.

Abstract: An outer diameter of a mandrel with a recess to accommodate lower slips with a larger thickness, a sealing element with a concave outer diameter to control a pressure differential caused by a Bernoulli Effect across the sealing element, and a disc that is selectively secured to a housing via a removable shear pin, wherein shear pins with different pressure ratings may be inserted into the housing.

Abstract: A system provides for the remote activation and deactivation of a downhole tool such as an agitator tool. The downhole tool uses a dart-catching section configured with a profile that engages with a corresponding key section of a dart. Different tools in the string may have different profiles, allowing darts to pass through tools to reach a tool with a matching profile further downhole. The dart includes a removable nozzle that can be detached by a object dropped from the surface, after which a second dart may be dropped to engage with the first dart to change operating parameters of the tool.

Abstract: Apparatus, systems, and methods for reverse circulation cementing a tubular string in a wellbore. One such method includes reverse circulating cement slurry down an annulus defined between the tubular string and the wellbore. During the reverse circulation, a flow control device located in the tubular string is closed to prevent, or at least reduce, flow of the cement slurry from the annulus into the tubular string. The closure of the flow control device causes a pressure pulse in the wellbore. After the flow control device is closed, the reverse circulation is stopped. During a time interval between the closure of the flow control device and the stoppage of the reverse circulation, a shock absorber associated with the flow control device absorbs the pressure pulse in the wellbore so that a pressure in the wellbore is maintained within an acceptable range.

Abstract: A retrievable in-flow control device (ICD) including a device body having a first end, a second end, an outer surface extending between the first end and the second end, and an internal flow path. A wireline connector is arranged at the first end. A latch mechanism is provided on one of the wireline connector and the device body. A flow control port extends through the outer surface to the internal flow path. An equalizer member including a first flow path for passing a first fluid and a second flow path for resisting flow of a second fluid. The retrievable ICD also includes a flow control device establishes a selected pressure drop of the first fluid through the retrievable ICD.

Abstract: A borehole tool, having a cylindrical body, the cylindrical body having an upper shank, a lower shank, and a component tool disposed between the upper shank and the lower shank, wherein the tool is configured to have an outer surface airfoil configuration, whereby lift is created as fluid passes along the cylindrical body. The component tool can be a combination stabilizer tool, a reamer tool and a cutting removal tool, wherein the stabilizer tool is configured as a helical stabilizing blade and reamer blade, a flow path disposed between the helices of the stabilizing and reamer blade, the stabilizing and reamer blade further comprising a reamer cutting element disposed where an edge of the stabilizing and reamer blade meets the flow path.

Abstract: A system for automatically evacuating liquids from natural gas pipelines. An embodiment may be used for associated drip vessels and other containers and gas wells. The system includes a tank, a compressor, and an electric generator system. The system evacuates liquid from a pipeline by creating a pressure differential between the pipeline and the tank. When adequate pressure differential is achieved, liquids flow into the tank from the pipeline. When liquids are removed, the system shuts down and awaits a run signal. The system is suited for remote locations, due, in part, to the use of an automatic generator capable of providing power to the compressor and to the CPU as necessary. Liquid removal may be determined by measuring tank pressure at time intervals and determining a rate of change of tank pressure for indicating blow through. The system utilizes the same pipeline tap for liquid removal and gas injection.

Abstract: A powder metallurgical component has a chromium content of at least 80% by weight and pores and/or oxide inclusions which are present in the component. The number per unit area of a sum of pores and oxide inclusions at a cut surface through the component in at least one region is at least 10,000 per mm2.

Abstract: An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured valving member with curved and flat portions that alternatively direct fluid flow through a bore or opening in the valving member via an inner channel or around the periphery of the valving member in an outer channel. In one embodiment, the ball(s), dart(s) or plug(s) are contained in a sliding sleeve that shifts position responsive to valve rotation. An optional indicator indicates to a user or operator that a ball or plug has passed a selected one of the valving members.

Abstract: A disclosed dynamic receiver includes a housing defining a receiver chamber and having a first end cap at one end of the housing and a second end cap at an opposing end of the housing, a flexure membrane arranged within the receiver chamber and providing a membrane wall having a first end that is closed and arranged adjacent a fluid inlet into the receiver chamber and a second end that is open and secured to an inner wall of the receiver chamber, and a piston assembly movably arranged in the receiver chamber and including a piston head and a piston rod extending axially from the piston head, wherein, as filtrate from a test fluid enters the fluid inlet, the filtrate acts on the flexure membrane such that hydraulic fluid disposed within the membrane cavity is displaced and thereby moves the piston assembly axially within the receiver chamber.

Abstract: An annular seat structure, for use in subterranean well stimulation operations, is operative in conjunction with associated expansion control structure to permit a predetermined number of fracture plug members to axially pass therethrough. In an illustrated embodiment thereof, the annular seat structure is movable between a retracted position having a first interior diameter, and a resiliently expanded position having a second, larger interior diameter. The seat structure has an annular array of rigid ring segments interdigitated with annular gaps that receive radially outwardly projecting portions of an annular resilient liner secured to radially inner surfaces of the rigid ring segments, the outwardly projecting liner portions being secured to circumferentially facing surfaces of the rigid ring segments. An annular spring member coaxially circumscribes the rigid ring segment array, is received in notches formed in the rigid segments, and resiliently biases the seat structure toward its retracted position.

Abstract: Low profile valves are described. In an embodiment, a tubular member for fluid transport has a valve constructed within a wall of the tubular member for controlling a radial flow of fluid, such as water, oil, or gas, through the wall without impeding the flow of fluid or tools through the tubular member or near the exterior of the tubular member. The low profile valve may be used, for example, in the oil and gas industries as a pressure relief valve or check valve. When used as a pressure relief valve, a load member such as a spring, strap, or rocker arm maintains a backpressure on the valve. Example low profile valves can provide flow control from within a very thin annulus between other components.

Abstract: A device is described for a system for conducting tests of a well, pipe or the like, where a plug of a removable material is inserted in a pipe through a well to carry out said tests. The device is characterized in that the wall parts of the pipe comprise channel borings (3,4,8) that set up fluid connections between the well space (70) and the well space (72) above and below, respectively, the plug, and that it comprises a closing body that can close the fluid connection permanently. The channel boring is preferably defined by an axial hollow space/chamber (4) in which a piston is arranged, said piston can be readjusted by an axial movement from a first position where there is fluid connection through the channel and a second position where the connection is permanently closed and can not be reopened.

Abstract: A subsurface safety valve features no flow tube to operate the flapper and optionally an equalizing valve in the flapper, if used. It relies on magnetic force that is selectively created to draw the flapper to the open position. A torsion spring can close the valve when the field is removed. Optionally, the fields can be set up to pull and push the flapper open or to do either one. The optional equalizer valve can also be operated by a force field, preferably magnetic.

Abstract: A drill string element for use in the drilling of a borehole, the drill string element comprising: a main body; and a flow control mechanism, wherein the drill string element defines a first aperture, another aperture and a passage configured to provide a fluid flow path between the first aperture and the other aperture, the first and other apertures provide fluid communication between a volume around the drill string element and the passage, and the flow control mechanism is configured to inhibit the flow of fluid through the passage in a first operating mode and to permit the flow of fluid through the passage in a second operating mode.

Abstract: An auto-fill type float collar assembly is provided. The float collar assembly of the present invention has at least one curved flapper-style valve, preferably constructed of composite, non-metallic material. Each flapper of the present invention has a substantially 90° range of motion, and is closed via a torsion spring. Each flapper is held in the open (or “auto-fill”), position via an external shifting mechanism passing around, rather than through, the central flow bore of the assembly. A floatable actuation ball can be run with the tool, or pumped downhole, in order to selectively actuate the assembly and close the flappers when desired.

Abstract: A back-up ring for use in a liner top test tool for testing casing integrity in a wellbore is disclosed. The back-up ring is comprised of first and second ring elements that are biased apart by a compression springs. The first ring element has a plurality of radially extending flanges that cover a plurality of channels in the second ring element when the back-up ring is compressed against a seal element on the liner top test tool to seal the wellbore casing.

Abstract: An apparatus for downhole separation of an oil/water fluid and the injection of the separated water into the formation includes a casing in a borehole, a tubing string in the casing, first perforations in the casing at a production zone in the borehole for admitting the mixture into an annulus between the casing and the tubing string, second perforations in the tubing string for admitting production fluid from the casing into the tubing string, third perforations in the casing for discharging separated water from the annulus into the formation, a packer in the annulus separating the first perforations from the third perforations, a first check valve in the tubing string above the packer for admitting the mixture from the tubing string into the annulus where water separates by gravity from the hydrocarbons for discharge through the third perforations, and a second check valve in the tubing string above the first check valve for admitting separated hydrocarbons from the annulus into the tubing string for passag

Abstract: An apparatus usable with a well includes a gas lift valve having a check valve arrangement located between an annulus and a passageway of a tubing. The check valve arrangement is adapted to selectively allow fluid flow from the check valve arrangement from an inlet side of the check valve arrangement to an outlet side of the check valve arrangement, and is biased to prevent a leakage flow through the check valve arrangement from the outlet side to the inlet side. The check valve arrangement is defined by a valve element movable into and out of engagement with a valve seat wherein one of the valve element and the valve seat has a first sealing structure engageable with a second sealing structure on the other of the valve element and the valve seat. At least one of the first and second sealing surfaces include at least one pair of sealing members.

Abstract: An auto-fill type float collar assembly is provided. The float collar assembly of the present invention has at least one curved flapper-style valve, preferably constructed of composite, non-metallic material. Each flapper of the present invention has a substantially 90° range of motion, and is closed via a torsion spring. Each flapper is held in the open (or “auto-fill”), position via an external shifting mechanism passing around, rather than through, the central flow bore of the assembly. A floatable actuation ball can be run with the tool, or pumped downhole, in order to selectively actuate the assembly and close the flappers when desired.

Abstract: An apparatus usable with a well includes a gas lift valve having a check valve arrangement located between an annulus and a passageway of a tubing. The check valve arrangement is adapted to selectively allow fluid flow from the check valve arrangement from an inlet side of the check valve arrangement to an outlet side of the check valve arrangement, and is biased to prevent a leakage flow through the check valve arrangement from the outlet side to the inlet side. The check valve arrangement is defined by a valve element movable into and out of engagement with a valve seat wherein one of the valve element and the valve seat has a first sealing structure engageable with a second sealing structure on the other of the valve element and the valve seat. At least one of the first and second sealing surfaces include at least one pair of sealing members.

Abstract: An apparatus for releasing gas pressure from a drill string includes a tubular housing having a circumferential sidewall, an axis, a first end, a second end and a central passage extending between the first end and the second end. A pressure member is positioned in the central passage along the axis of the housing. The pressure member is movable from a first position retracted within the housing to a second position extending past the second end of the housing. An actuator is provided to move the pressure member from the first position to the second position, where the pressure member exerts a force to move a valve member of a float valve to an open position, thereby allowing gas trapped in the drill string to flow through the central passage.

Abstract: A production sleeve assembly for use downhole comprises a fluid pathway configured to provide fluid communication between an exterior of a wellbore tubular and an interior of the wellbore tubular, a flow restriction disposed in the fluid pathway, and a valve disposed in series with the flow restriction in the fluid pathway. The valve comprises: a rupture disk and a plug releasably engaged in the fluid pathway in series with the rupture disk. The valve is configured to allow production from the exterior of the wellbore tubular to the interior of the wellbore tubular through the chamber without producing past the plug once the rupture disk is actuated.

Abstract: A flow stop valve positionable in a downhole tubular, and a method. The flow stop valve is in a closed position when a pressure difference between fluid outside the downhole tubular and inside the downhole tubular at the flow stop valve is between a threshold value, thereby preventing flow through the downhole tubular. The flow stop valve is in an open position when the pressure difference between fluid outside the downhole tubular and inside the downhole tubular at the flow stop valve is above a threshold value, thereby permitting flow through the downhole tubular.

Abstract: A hydraulic connection mechanism for use in a wellbore comprises an upper connection tool, a lower connection tool configured to engage the upper connection tool and form a fluid communication pathway through the hydraulic connection mechanism, and a debris barrier disposed in the fluid communication pathway. The debris barrier comprises a body element, and a spring element configured to maintain the body element in a closed position when the upper connection tool is disengaged from the lower connection tool.

Abstract: A check valve for gas lift applications can be attached externally to a side pocket mandrel or can be a gas lift valve used in the mandrel. The valve has a seat with a non-elastomeric element and a metal element. A biasing element resiliently biases the non-elastomeric element to provide resiliency to the seal produced. A metal dart moves in the bore relative to the seat and allows or prevents flow through the valve body. When exposed to a first differential pressure, the dart engages the non-elastomeric element resiliently biased by the biasing element. When exposed to a greater differential pressure, the dart engages the metal element, which can be part of the valve in the bore. In one arrangement, the non-elastomeric element can be a thermoplastic component with a metal spring energized seal as the biasing element. Alternatively, the non-elastomeric element can be the jacket of metal spring energized seal with a coil spring as the biasing element.

Abstract: Certain aspects of the present invention are directed to a liquid valve assembly that can be disposed in a wellbore through a fluid-producing formation. The liquid valve assembly can include a housing and a liquid valve. The housing can define an inner chamber and an opening adapted to allow fluid to flow between the inner chamber and a passageway. The liquid valve can be disposed in the inner chamber. The liquid valve can include a yield stress fluid. The yield stress fluid can prevent fluid from flowing between the inner chamber and the passageway.

Abstract: A pressure-actuated valve fit to a tubing string for alternately closing to communicate fluids from a wellbore to the tubing string and opening to communicate fluids from a wellbore annulus to the tubing string. The valve is particularly useful for lifting liquids which accumulate in the tubing string when the reservoir has a diminished pressure. In this case, gas is accumulated in the wellbore annulus and when the valve is opened the gas enters the valve and is directed to the tubing string for lifting the liquids. The valve is closed by a spring and has a closing-assist which applies an additional force to the spring to ensure the valve is fully closed.

Abstract: A float valve with upper and lower valve bodies having axial flow there through and valve member having angular trailing edges at a swept back angle for providing a seating surface and a stem axially extending from the valve member. The stem having multiple supporting surfaces arranged cylindrically and having a biasing member fitted there about. The upper valve body having an internal annular seat for seating with the valve member seating surface and external seals for engaging oilfield tubulars and threaded on one end. The lower valve body having a central internal support member for support of the valve member stem for axial movement and threaded on one end for joining the upper valve body and compressing the biasing member to engage the seating surfaces of the valve member and internal annular seat of the upper valve body for engagement and disengagement in response to fluid flow pressure.

Abstract: A flow stop valve (20) positionable in a downhole tubular (6), and a method, are provided. The flow stop valve (20) is in a closed position when a pressure difference between fluid outside the downhole tubular (6) and inside the downhole tubular (6) at the flow stop valve (20) is below a threshold value, thereby preventing flow through the downhole tubular. The flow stop valve (20) is in an open position when the pressure difference between fluid outside the downhole tubular (6) and inside the downhole tubular (6) at the flow stop valve (20) is above a threshold value, thereby permitting flow through the downhole tubular (6).

Abstract: A hydraulic connection mechanism for use in a wellbore comprises an upper connection running tool, a lower connection tool configured to engage the upper connection running tool and form a fluid communication pathway through the hydraulic connection mechanism, and a debris barrier disposed in the fluid communication pathway. The debris barrier comprises a body element, and a spring element configured to maintain the body element in a closed position when the upper connection running tool is disengaged from the lower connection tool.

Abstract: A downhole tool and system are provided. In at least one specific embodiment, the downhole tool can include a tubular housing having an inner bore and a valve seat. A sleeve can be disposed in the inner bore and can be configured to move between a first position and a second position within the tubular housing. A flapper valve can be coupled to the tubular housing, such that the flapper valve is stationary when the sleeve is in the first position. The flapper valve can be pivotable between an open position and a closed position when the sleeve is in the second position. A biasing member can be coupled to the flapper valve and to the tubular housing. The biasing member can be configured to bias the flapper valve toward the valve seat.

Abstract: The present invention regards a valve device for use with a down hole tool comprising at least a first fluid line and a return fluid line, the valve device comprises a first inlet and a first outlet forming a first flow path between them, and a second inlet and a second outlet forming a second flow path between them, at least one closure element for closing and or opening at least one of the flow paths. According to the invention there is at least one closure element together with the respective flow paths forms a first and second check valves, which in a first state prevents a fluid from flowing from the first outlet to the first inlet and a fluid from flowing from the second inlet to the second outlet. The invention also regards a method for operating a down hole valve device.

Abstract: A down-hole jet pumping apparatus and method for removing accumulated water in a small diameter well bore are described. Chosen fluids are pumped under high pressure from a surface pump through a 3-way valve into a tube disposed in a well bore. The jet pumping apparatus includes a down-hole accumulator connected to an eductor. The high-pressure fluid is stored in the accumulator and may be released to the surface reservoir by the control valve through the tube along with the fluid to be pumped drawn into the eductor. When the accumulator is exhausted, the control valve again directs high-pressure fluid from the surface pump to the accumulator until a chosen pressure is achieved in the accumulator. The fluid pressure in the accumulator is maintained using a gas-charged metal bellows. Hydraulically driven jet boosters are described for increasing the fluid pressure along the tube in deep wells.

Abstract: A check valve comprising a section of a drill string, a flapper valve positioned within and concentric to the section of the drill string, and a piston valve positioned within and concentric to the section of the drill string. The flapper valve allows fluid flow in a first direction through an inner portion of a cross-section of the section of the drill string and not allowing fluid flow in a second direction, and the piston check valve allowing fluid flow in the first direction through an outer portion of the cross-section of the section of the drill string and not allowing fluid flow in the second direction, where the first portion and the second portion of the cross-section of the section of the drill string are mutually exclusive.