Abstract: A blowout preventer may be used for shearing an object positioned in a vertical bore extending through the blowout preventer. The blowout preventer includes a shear ram movable towards the tubular, the shear ram including a biasing mechanism for biasing against an interior surface of the blowout preventer body. In this way, the biasing mechanism urges the shear ram into axial engagement with an opposing shear ram movable towards the tubular during shearing operations. The biasing mechanism comprises a biasing member, such as a coiled spring, coned-disc spring, and/or coned-disc washer which urges the biasing mechanism into contact with the inner portion of the blowout preventer body.

Abstract: A ram blowout preventer (“BOP”) may be used for sealing about an object positioned in a vertical bore extending through the BOP. The ram BOP includes a body comprising a vertical bore extending through the body and a ram cavity intersecting the bore, a ram assembly movable laterally into and out of the BOP vertical bore and comprising a ram body, and an opposing ram assembly movable laterally into and out of the BOP vertical bore and comprising a ram body and a seal body coupled to the ram body, wherein the seal body comprises a seal configured to seal the entirety of the BOP vertical bore. The seal can be located on the upper and/or lower portion of the seal body to provide for bi-directional sealing across the BOP.

Abstract: A stabilizer for a pipe being removed from a well comprises a body formed of body segments where the body segments are separable to allow the body to open and be wrapped around the pipe. The stabilizer has a first annular seal formed by first seal elements within the body for receiving and stripping the pipe, and may have a second annular seal. The body segments may be hinged together about a hinge that may be configured to limit the movement of the body segments relative to each other. The hinge may comprise an interdigitated first and second row of fingers.

Abstract: An articulated debris barrier folds on itself to extend radially to span a surrounding annular gap when the tool associated with it is set. The debris barrier can be used with a packer or bridge plug. The set position of the packer or plug is locked and another lock holds the extended position of the debris barrier. The debris barrier lock can be a snap ring that extends into a groove brought into alignment with it during the setting. Alternatively the lock for the debris barrier can be a body lock ring. In either case, release and retrieval of the packer or plug involves undermining of the locking feature for the debris barrier so that the debris barrier can extend while retracting from the borehole wall so that the barrier and the associated packer or plug can be removed together.

Abstract: Devices and methods related to setting and testing a packer in a single trip are disclosed. Embodiments disclosed herein provide a tubing engagement element for applying longitudinal force to expand the packer element, such as by compressing an elastomeric element longitudinally to cause radial expansion. Further, upon application of longitudinal force, a second packer element, inside of the first, also sets, isolating the interior of the packer form the exterior. The isolation on the interior of the packer, or tubing attached thereto, permits formation of a pressure differential across the installed packer, facilitating a pressure test to ensure that the packers is adequately set.

Abstract: A riserless well abandonment system includes a surface vessel, a first mast extending from the surface vessel, a second mast extending from the surface vessel, wherein the second mast is spaced from the first mast, a running tool extending from the first mast, wherein a subsea intervention device is coupled to the running tool, and a concentric drill string extending from the second mast, wherein the concentric drill string includes an inner drill pipe disposed within an outer drill pipe.

Abstract: A choke valve system includes a choke valve having a body and an annular seat disposed within the body. The choke valve also includes a plug configured to move relative to the annular seat between an open position in which a fluid is enabled to flow through the choke valve and a closed position in which the fluid is blocked from flowing through the choke valve and in which the plug contacts an annular seating surface of the annular seat. The choke valve further includes a damper coupled to the plug, and the damper is configured to absorb a load generated by contact between the plug and the annular seating surface of the annular seat as the plug moves into the closed position.

Abstract: An arming apparatus for arming a downhole tool in a wellbore casing comprising an arming member and a holding device. The arming member disposed within an outer housing of the downhole tool and the holding device mechanically coupled to the arming member. When a ball deployed into the wellbore casing passes through the downhole tool in a downhole direction and moves back in an uphole direction due to reverse flow, the ball engages on the holding device and functions the arming member such that a pressure actuating device in the downhole tool is armed.

Abstract: An apparatus for reducing or eliminating gas lock in a downhole pump is provided. The apparatus has a ported bushing connecting to an upper standing valve at a first, uphole end and connecting to a lower standing valve at a second, downhole end. The apparatus also has one or more vents. In one embodiment, the apparatus is coupled downhole of a traveling valve of a downhole pump such that, on each upstroke, the one or more vents of the apparatus draw liquid from the annulus between the pump and the tubing into the passage between the upper and lower standing valves for opening the upper standing valve to accumulate liquid in the pump barrel below the traveling valve. The accumulation of liquid in the pump barrel below the traveling valve breaks gas lock and opens the traveling valve, ensuring the operation of pumping liquid from downhole to surface.

Abstract: A tubular string is run into a wellbore with a remotely actuated valve near a lower end adjacent a cementing shoe. The valve is triggered to operate without intervention such as by mud pulses generated at the surface and recognized by a sensor linked to a processor adjacent the valve to trigger the valve to close. Alternative actuation systems are envisioned for the valve that is located near the cementing shoe.

Abstract: A catch-and-release tool conveyed with a well casing for use in a wellbore comprising an outer housing having flow ports therethrough, a functioning apparatus disposed within the outer housing comprising a movable member/sleeve and a holding device, and a blocking apparatus comprising a blocking member configured to block the flow ports in a first position. When a ball deployed into the well casing passes through the tool in a downstream direction and moves back in an upstream direction, the restriction element engages onto the holding device and moves the movable member such that a port in exposed to up hole pressure and the blocking member travels to a second position in a reverse direction unblocking flow ports and enabling fluid communication to the wellbore. The ball is thereafter released in an upstream direction.

Abstract: An actuating apparatus for actuating a downhole tool in a wellbore casing comprising an actuating member and a holding device. The actuating member disposed within an outer housing of the downhole tool and the holding device mechanically coupled to the arming member. When a ball deployed into the wellbore casing passes through the downhole tool in a downhole direction and moves back in an uphole direction due to reverse flow, the ball engages on the holding device and functions the actuating member such that a port in the downhole tool is exposed to uphole pressure and actuates the actuating member to travel in an uphole direction.

Abstract: A seat forming apparatus for use in a downhole tool comprising a driving member and a seating restriction is disclosed. 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: A seat forming apparatus for use in a downhole tool comprising a driving member and dog elements that are disposed and movable within an outer housing of the downhole tool. The dog elements align in grooves recessed in the outer housing of the downhole tool in a first position and disengage from the grooves in a second position. The driving member travels in a reverse direction and enable the dog elements to move from the first position to the second position and form a seat in the downhole tool. The seat formed has an inner diameter smaller than the restriction element to allow the restriction element to be seated.

Abstract: A multiple tool reverse flow system and method in a wellbore casing for use in a wellbore is disclosed. The system comprises a plurality of catch-and-release tools and a catch-and-engage tool, wherein the catch-and-release tools allow a restriction element to pass through in a downstream direction and engage and then allow the restriction element to pass through in an upstream direction. The catch-and-engage tool allows the restriction element to pass through only in a downstream direction, engage and restrict travel of the restriction element in an upstream direction. The catch-and-engage tool forms a seat on an upstream end is positioned upstream of all of catch-and-release tools. The restriction element passes through all the tools in a downstream direction and moves back in an upstream direction and actuates each of the tools one at a time.

Abstract: A catch-and-engage tool conveyed with a well casing for use in a wellbore comprising an outer housing having flow ports therethrough, a functioning apparatus disposed within the outer housing comprising a movable member/sleeve and a holding device, a blocking apparatus disposed within the outer housing comprising a blocking member configured to block one or more flow ports in a first position, a seating apparatus positioned upstream of the blocking apparatus configured to form a seat in the tool. When a ball deployed into the well casing passes through the tool in a downstream direction and moves back in an upstream direction, the restriction element engages onto the holding device and moves the movable member such that a port in exposed to uphole pressure and the blocking member travels to a second position in a reverse direction unblocking flow ports and enabling fluid communication to the wellbore.

Abstract: A sleeve actuation method for actuating sleeves in a reverse direction. The method includes a use of stored energy created by injecting into a connected region of a well such that the stored energy is used to actuate a tool installed in a wellbore casing that is either heel ward or uphole of the connected region. The tool actuated in a direction from toe end to heel end while the tool reconfigures to create a seat for seating plugging elements.

Abstract: A bottom hole actuator tool is provided for locating and actuating one or more sleeve valves spaced along a completion string. A shifting tool includes radially extending dogs at ends of radially controllable, and circumferentially spaced support arms. Conveyance tubing actuated shifting of an activation mandrel, indexed by a J-Slot, cams the arms radially inward to overcome the biasing for in and out of hole movement, and for releasing the arms for sleeve locating and sleeve profile engagement. A cone, movable with the mandrel engages the dogs for positive locking of the dogs in the profile for sleeve opening and closing. A treatment isolation packer can be actuated with cone engagement. The positive engagement and compact axial components results in short sleeve valves.

Abstract: Embodiments of machines, systems, computer-implemented methods, and computer program products certify oil and. gas well equipment. Embodiments identify a selected well equipment device, a device test specification, and testing sequences to be performed by a corresponding testing apparatus. Embodiments select a testing sequence responsive to the selected device. Embodiments control the testing apparatus for the selected testing sequence so that the corresponding testing apparatus performs the sequence responsive to the device test specification. Embodiments generate testing data for the selected testing sequence and link the testing data for the selected testing sequence to the device identifier for the device so that a certificate can be generated. Embodiments generate a certificate for the selected device responsive to the testing sequences having been performed upon the selected device and link the certificate for the selected device to the device identifier so that the certificate can be readily recalled.

Abstract: Deepwater extended hardrock completion systems comprising a wellbore penetrating a subsea subterranean formation, wherein the wellbore comprise a near vertical first portion, a deviated second portion, and a deviated third portion.

Abstract: A technique facilitates assembly and deployment of a sand screen assembly string. The sand screen assembly string is constructed by providing sequential base pipe joints combined with corresponding alternate path tubes. The sequential base pipe joints are joined together in a manner which brings sequential, corresponding alternate path tubes into close proximity with each other at a location external to the sequential base pipe joints. The sequential, corresponding alternate path tubes are readily coupled together by a connector which is movably mounted along at least one of the alternate path tubes for movement into engagement with the other alternate path tube.

Abstract: A perforating tool includes an encapsulated shaped charge that has a bulkhead with a reduced wall thickness section, a plate having a shallow recess, and a detonating cord having an energetic core. The energetic core forms the plate into an explosively formed perforator when detonated. The plate is positioned to direct the explosively formed perforator into the reduced wall thickness section.

Abstract: A perforating gun includes a charge tube disposed inside a carrier and a plurality of sets of shaped charges axially distributed along the charge tube and the initiation tube. Each shaped charge of the plurality of shaped charges is supported at an opening in the charge tube. The perforating gun also includes a plurality of detonator cords. Each detonator cord of the plurality of detonator cords connects to one shaped charge in each set of shaped charges.

Abstract: A method of controlling flow in a well can include a device introduced into the well being conveyed by flow in the well, and the device having a plurality of fibers extending outwardly from a body, the fibers being retained by a retainer. A well system can include a flow conveyed device conveyed through a tubular string by flow in the tubular string, and the flow conveyed device including a body with a plurality of fibers extending outwardly from the body. A retainer can at least partially enclose the device. A flow conveyed device for use in a well can include a body, and a plurality of fibers joined to the body, each of the fibers having a lateral dimension that is substantially smaller than a size of the body.

Abstract: A plunger piston assembly for a plunger lift system used to remove fluids from a subterranean wellbore includes a sealing sleeve having a central axis, an upper end, a lower end, and a throughbore extending axially from the upper end of the sealing sleeve to the lower end of the sealing sleeve. The throughbore of the sealing sleeve defines a receptacle extending axially from the lower end of the sealing sleeve. In addition, the plunger piston assembly includes an intermediate sleeve having a central axis, an upper end, a lower end, and a throughbore extending axially from the upper end of the intermediate sleeve to the lower end of the intermediate sleeve. The throughbore of the intermediate sleeve defines a receptacle extending axially from the lower end of the intermediate sleeve. The upper end of the intermediate sleeve is configured to be removably seated in the receptacle of the sealing sleeve.

Abstract: A dart valve assembly for a bypass plunger is disclosed including a dart valve and a clutch. The clutch bobbin, installed within the bore of a valve cage or a plunger body, is formed of a synthetic material. The clutch restrains the movement of the dart valve within it as the dart valve moves between a closed and an open position. The synthetic bobbin reduces friction and substantially increases the service life of the dart valve assembly. The clutch bobbin surrounds and exerts a predetermined clamping tension on the stem of the dart valve. Both the outside diameter of the dart valve stem and the inside diameter of the clutch bobbin are configured with a sequence of alternating ridges and grooves to improve clutch action.

Abstract: A ground fault immune power and data delivery system for downhole sensors is connected to a downhole motor via a three-phase power cable. An AC power supply and sensor data module are connected to only two of the three phases to provide power and data signals to the sensors. During normal operation, power and data signals are transmitted over only one of the two connected phases. If a ground fault is detected on the third unconnected phase, power and data signals continue to transmit over the connected phase. If a ground fault is detected on one of the two connected phases, an isolation module isolates the grounded phase and switches to the ungrounded connected phase to continue transmitting power and data signals. If two of the phases are grounded, the motor shuts off; however, power and data signals may continue to transmit over an ungrounded connected phase.

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: There is provided systems and methods for controlling the inflow of materials into a production well during recovery of hydrocarbons from a hydrocarbon-containing reservoir. The system includes a flow control device configured to limit steam flow and hot water flow from the hydrocarbon-containing reservoir.

Abstract: An apparatus associated with a drilling rig includes a surface steerable system for controlling drilling direction of a bottom hole assembly (BHA). The surface steerable system is configured to receive drilling rig parameters from the BHA. A database stores historical data related to the drilling rig. The historical data relates to previously tracked operations of the drilling rig. The surface steerable system is further configured to perform a plurality of tracking functions with respect to the drilling rig parameters. The plurality of tracking functions cause the surface steerable system to track drilling rig parameters from sensors associated with the drilling rig, access the database of the historical data relating to previously tracked operations of the drilling rig and control operating functions of the drilling rig responsive to at least one of the drilling rig parameters from the sensors associated with the drilling rig and the historical data from the database.

Abstract: Methods for drilling a wellbore within a subsurface region and drilling assemblies and systems that include and/or utilize the methods are disclosed herein. The methods include receiving a plurality of drilling performance indicator maps, normalizing the plurality of drilling performance indicator maps to generate a plurality of normalized maps, adaptive trending of the plurality of drilling performance indicator maps to generate a plurality of trended maps, summing the plurality of trended maps to generate an objective map, selecting a desired operating regime from the objective map, and adjusting at least one drilling operational parameter of a drilling rig based, at least in part, on the desired operating regime.

Abstract: A method of controlling drill bit trajectory in a subterranean formation includes receiving drilling parameters for operating a specific bottomhole assembly (BHA), constructing, with a computer processor, a directional drill-ahead simulator including a computer model of the BHA and the subterranean formation, calculating axial motion and lateral motion of a drill bit connected to a bottom end of the BHA using formation parameters and drilling parameters, predicting bit walk of the drill bit by accounting for and calculating contact forces and frictional forces between the BHA and a wall of a borehole in the subterranean formation using the computer model of the BHA, and determining an adjusted drill bit trajectory to account for the predicted bit walk. The method includes determining adjusted drilling parameters for operating the BHA to substantially follow the adjusted drill bit trajectory and operating the BHA according to the adjusted drilling parameters.

Abstract: A diagnostic apparatus configured to communicate with a well test system comprising a plurality of wells in a field, comprising a receiving component configured to receive a well test data from the well test system, a transmitting component configured to transmit an abnormal well test signal indication, at least one processor configured to communicate with the transmitting component and the receiving component, and a memory coupled to the at least one processor, wherein the memory comprises instructions that when executed by the at least one processor cause the diagnostic apparatus to compare the well test data to one or more well test descriptors stored in memory, correlate the well test data to an abnormal well test result selected based at least in part on the comparison with the one or more well test descriptors stored in the memory, and instruct the transmitting component to transmit an abnormal well test signal indication to a recipient.

Abstract: A well bore is inspected to detect cement defects that can give rise to leakage. The well bore comprises an inner metal pipe. Outside the inner metal pipe its configuration may vary with distance from the top of the well bore in terms of concentric pipes outside the inner metal pipe and presence of cement between the pipes. A probe with is lowered through the inner metal pipe. An ultrasound signal is transmitted from the probe into the inner metal pipe and responses to the transmitted signal are received at a series of ultrasound receivers at different axial positions. A selection of a spatial frequency of waves arriving along the axial direction at the ultrasound receivers and/or the apparent velocity of said waves is retrieved dependent on the configuration. The received responses are band pass filtered accordingly.

Abstract: A system including a hydrocarbon extraction system configured to receive a pressurized fluid, the hydrocarbon extraction system, including a non-invasive capacitive pressure measurement system configured to measure a pressure of the pressurized fluid, the non-invasive capacitive pressure measurement system, including a housing, a core configured to rest within the housing, and an insulative material between the core and housing wherein the insulative material is configured to provide a gap between the core and the housing to form a capacitor.

Abstract: A method for providing a location of equipment external to a downhole pipe within a wellbore by detecting or generating magnetic or electromagnetic fields within the downhole pipe and measuring the magnetic/electromagnetic field disturbances caused from one or more magnetic generating entities. The magnetic generating entities are detected from the magnetic/electromagnetic field disturbances and the location of the pipe external equipment is determined based upon the magnetic/electromagnetic field disturbances caused from the magnetic generating entities. In another embodiment, an apparatus that comprises at least one pipe external equipment coupled to a downhole pipe within the wellbore, and at least one magnetic field generating entities coupled relatively close or at a known geometric distance to the at least one pipe external equipment. The magnetic field generating entities are coupled to at least one pipe external equipment using a fastening component or installed in the downhole pipe or pipe mandrel.

Abstract: A portable locator and method for establishing the location of the cable line in a region which includes at least one generally straight electrically conductive cable line extending across the region from which cable line a locating signal includes a first arrangement for measuring a local flux intensity of the locating signal at a first above ground point within the region with the portable locator in a particular orientation at the first above ground point. A second arrangement uses the local flux intensity to establish a cable line angular orientation which limits the possible directions to the cable line relative to the particular orientation of the portable locator at the above ground point. A third arrangement uses the measured local flux intensity to establish an actual direction of the cable line that is selected from the possible directions based on certain characteristics of the locating signal.

Abstract: An apparatus for metering fluid in a subterranean well includes an electric submersible pump having a motor, a seal section and a pump assembly and a metering assembly. The metering assembly includes an upper pipe section with an outer diameter, the upper pipe section having an upper pressure sensing means, and a lower pipe section with an outer diameter smaller than the outer diameter of the upper pipe section, the lower pipe section having a lower pressure sensing means. A power cable is in electronic communication with the electric submersible pump and with the metering assembly.

Abstract: A bottom hole assembly includes a cable to transmit power and communication signals. A first measurement-while-drilling tool is coupled with the cable. A second measurement-while-drilling tool is coupled with the cable. An adapter is coupled with the cable and positioned between the first and second measurement-while-drilling tools. The adapter includes a disconnect in the cable that prevents the power from being transmitted through the adapter. A repeater is coupled with the cable and amplifies the communication signals transmitted through the cable.

Abstract: Dimensionality reduction systems and methods facilitate visualization, understanding, and interpretation of high-dimensionality data sets, so long as the essential information of the data set is preserved during the dimensionality reduction process. In some of the disclosed embodiments, dimensionality reduction is accomplished using clustering, evolutionary computation of low-dimensionality coordinates for cluster kernels, particle swarm optimization of kernel positions, and training of neural networks based on the kernel mapping. The fitness function chosen for the evolutionary computation and particle swarm optimization is designed to preserve kernel distances and any other information deemed useful to the current application of the disclosed techniques, such as linear correlation with a variable that is to be predicted from future measurements. Various error measures are suitable and can be used.

Abstract: A mud pulser system for use in a wellbore includes a pulser assembly disposed in a drill string and through which drilling fluid is metered in order to generate pressure pulses in the drilling fluid. The pulser assembly includes a pulser body having an inlet and an exit. Included in the pulser body is a rotary member having multiple ports formed through the member. The rotary member can be spherically shaped. The ports are formed so that selectively rotating the rotary member registers opposing ends of a one of the ports with the inlet and exit in the body to provide communication between the inlet and exit. An actuator couples with the rotary member for its selective rotation.

Abstract: This disclosure describes a method for calculating the horizontal stresses that integrate both frictional equilibrium and uniaxial elasticity assumptions. The results are more accurate than either of the assumptions.

Abstract: The present disclosure involves a obtaining force and motion data from a measurement while drilling apparatus or the like having sensors measuring forces and motions of the drill bit while drilling a well. The force and motion data is transformed into spectral pairings from which distributions, such as force displacement and power law relationship, are generated. From the distributions various rock strength properties along the well bore may be derived and used in various possible completion processes such as perforation placements and packer placements.

Abstract: A liquid sampling container with an internal mixer includes a sealed outer body configured to hold a sample multi-phase fluid obtained from a multi-phase fluid stream. An inlet line is attached to the outer body. The sample multi-phase fluid flows into the sealed outer body through the inlet line. A piston assembly is positioned within the sealed outer body. The piston assembly is sealed to the inner walls of the outer body to define a sample volume in which the sample multi-phase fluid is contained. A shear mixer is positioned within the sealed outer body. The shear mixer includes a rotor and a stator arranged to define a fluid passage and rotatable relative to each other. The rotor includes a rotary shear blade configured to shear the sample multi-phase fluid such that a homogeneity of multiple phases in the sample multi-phase fluid remains substantially constant.

Abstract: A portable monitor used to measure landfill gas and landfill well parameters. The portable monitor includes a control unit and a measuring unit that can communicate wirelessly with one another. The control unit and/or measuring unit can include a heating arrangement to increase the temperature of one or more components in the control unit and/or measuring unit in cold environments.

Abstract: A hanging wall movement detection apparatus includes a rigid elongate member which extends between a first end and a second end, an indicator module which produces a warning signal when actuated, axially movably engaged with the elongate member, a ground engaging support which rigidly supports the indicator module off the ground, an actuator engaged with the elongate member between the first end and the indicator module, a biasing separator between the actuator and the indicator module. The actuator is drawn towards the indicator module, compressing the biasing separator, when the elongate member experiences a pulling force at the second end in an axial direction away from the indicator module, and the actuator contacts the indicator module to actuate the module to produce a warning signal if the pulling force is of a sufficient magnitude to overcome the bias of the biasing separator.

Abstract: The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have an elongate first island disposed thereon. The first island can have a body with a volume generally defined between front and rear surfaces that are spaced apart. The front and rear surfaces can lie in a plane parallel to a radial axis R. The perimeters of the front and rear surfaces can define a curved perimeter surface therebetween. The disclosure further provides embodiments having stationary islands and casings that rotate about the island.

Abstract: A method of assembling a rotor stack comprising a plurality of component parts, the method comprising: determining swash measurements for interfacing surfaces of the plurality of parts; calculating a runout estimate for a plurality of relative orientations of the parts; applying an optimisation algorithm to identify an optimal orientation from the plurality of relative orientations based on the runout estimates; and assembling the parts in the optimal orientation.

Abstract: A gas turbine engine having turbine discs includes a low diameter turbine rotor clamp for securing the turbine discs together. The rotor clamp includes a clamp sleeve, a clamp cylinder adapted to be threadably engaged to the clamp sleeve to apply an axial force on the turbine discs being coupled together. The rotor clamp includes an anti-score ring positioned between the bore of a turbine disc and the clamp cylinder and a lock tube used to prevent unwanted rotation of the clamp cylinder with respect to the clamp sleeve.

Abstract: A turbofan engine has a fan portion in fluid communication with a core stream and a bypass stream of air separated by splitters disposed both upstream and downstream of the fan portion. A fluid passage is defined between the splitters. The turbofan engine has a plurality of high pressure fluid jets originating from the low pressure side of the fan blades, the jets restricting the migration of the core stream into the bypass stream through the fluid passage.