Abstract: A method of detecting and mitigating flow instabilities, such as slugging, in one or more hydrocarbon production wells. Real-time production data pertaining to each well is retrieved. Using the production data, patterns of flow instability are identified therein. A numerical model of transient and thermal multiphase flow in each well is generated. Well test data is retrieved from a database. The numerical model is calibrated using the well test data. Using the calibrated numerical model, a parametric study is performed to determine how input parameters affect at least one of stability and performance of the wells. Results of the parametric study are queried to determine a type of flow instability and to determine operating conditions to improve performance of the wells. An advisory is provided to a user to change operating conditions of one or more of the wells, to improve stability and/or performance of one or more of the wells.

Abstract: Inhibiting or preventing corrosion of metallic components downhole may be accomplished by introducing neutralization media into a wellbore in the proximity of downhole metallic components, where the neutralization media comprises magnesium and where the method further includes subsequently contacting the neutralization media with a potentially corrosive environment comprising at least 5 volume % water, where the water has a pH of less than 11. This contacting activates the neutralization media with the water thereby releasing magnesium ions, and the magnesium ions react with hydroxyl ions of the water to give magnesium hydroxide in an amount effective to raise the pH of the water present to be between about 8 and 12 thereby inhibiting or preventing corrosion of metallic components downhole.

Abstract: A device is for perforation of a downhole formation. The device has an electronically induced acoustic shock wave generator; and an acoustic shock wave focusing member. The device is adapted to focus generated acoustic shock waves onto an area of a borehole in order to disintegrate the downhole formation within said area. The device is adapted to generate a plurality of consecutive focused acoustic shock waves in order to gradually excavate a perforation tunnel, or to improve an already existing perforation tunnel, extending from said borehole and into said formation.

Abstract: A sand control screen assembly having a protective shroud or jacket that provides a controlled offset between the shroud and a filter medium. The sand control screen assembly also includes a base pipe having a drainage layer positioned therearound for preventing the flow of particulate material of a predetermined size therethrough and allowing the flow of production fluids therethrough.

Abstract: Systems and methods to perform a downhole operations in a borehole comprising moving, using surface equipment, an inner structure and an outer structure within the borehole, the outer structure equipped with an interaction device and the inner structure configured to be moved relative to the outer structure in a direction parallel to the borehole by the surface equipment, transmitting, by a transmitter, a downlink instruction to the inner structure, and performing an interaction routine with the interaction device in response to the downlink instruction, wherein the interaction routine comprises an interaction at least partially outside of the outer structure to perform the downhole operation.

Abstract: A reservoir stimulation tool for stimulating a formation surrounding a wellbore having an inner wall includes: a tubular string including an outer wall defining therein an inner bore, the tubular string being configured to be inserted into the wellbore so as to form an annular space between the tubular string and the inner wall of the wellbore, a plurality of ports formed in the outer wall of the tubular string; a plurality of port valves for opening or closing the ports; and a plurality of packers coupled to the tubular string, wherein each packer is configured to be expanded in order to engage the inner wall of the wellbore, thereby isolating two or more longitudinal segments of the annular space from each other.

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, such as 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 process of stimulating hydrocarbon recovery is described and claimed. This process includes introducing a gas, a liquified gas or a vaporized liquified gas, into an underground formation containing hydrocarbons such as crude oil and gas, permitting said gas to be absorbed by said hydrocarbons, and withdrawing said hydrocarbons containing the gas therein, wherein a pill of Hydrocarbon Recovery Fluid comprising surface functionalized nanoparticles is inserted into the underground formation containing hydrocarbons before, during or after the introduction of the gas, liquified gas or a vaporized liquified gas.

Abstract: Herein is provided a process which includes hydraulically fracturing a subterranean formation with a fracking fluid that includes a nanobubble solution. Alternatively, herein is provide a process that includes hydraulically fracturing a subterranean formation that includes nanobubbles with a fracking fluid that may or may not include a nanobubbles.

Abstract: Methods and apparatus of pressure activated completion tools for hydraulic fracturing and related processes are provided. In some embodiments, the hydraulic fracturing apparatuses for accessing a subterranean formations can include a tubular body to be fluidly connected in-line with a completion string, the tubular body having at least one burst port configured to receive burst inserts (burst plugs), and a movable inner sleeve that can slide along the inside of the tubular body when exposed to hydraulic pressure from a first position to a second position. The tubular body can also have flow-port(s) that are blocked when the movable inner sleeve is in the first position and opened when the movable inner sleeve slides to the second position.

Abstract: A method of stimulating a formation containing two or more wellbores includes simultaneously stimulating a first region of each wellbore using a stimulation fluid so as to create a primary fracture in the first region of each wellbore, wherein the first region comprises a first opening or openings allowing fluid communication between each wellbore and the formation, wherein the first region has a first stimulated lateral length and wherein the flow rate of the stimulation fluid through the first opening or openings is greater than 1 barrel per minute per foot of the first stimulated lateral length.

Abstract: A vapor recovery apparatus degasses oil and water produced by an oil well. The apparatus has a first vessel forming a column. Oil containing gas enters the bottom of the first vessel and flows up to a liquid outlet. Heat applied to the rising oil, wherein the oil foams. Gas escapes into the upper end. The foam flows into a second column and along a roughened surface. The bubbles in the foam break apart releasing the gas. The oil flows down the second column to an outlet. Water is introduced into a third vessel. The water releases gas therein, which gas mingles with the gas from the oil. The third vessel is located around the first and second vessels. A compressor may be used to withdraw the gas and provide hot compressed gas to heat the rising oil in the first column.

Abstract: A sand and gas separation system for use with a rod pump. The system comprises an upper separator configured to separate out gas from wellbore fluids prior to flowing into the rod pump. The system further comprises a lower separator configured to separate out sand from wellbore fluids prior to flowing into the upper separator. The upper and lower separators are coupled together by a mechanical coupling.

Abstract: A system includes a continuous mud measurement system to measure one or more mud properties of a mud being pumped into a well, a continuous drilling measurement system to measure one or more drilling parameters of the well being drilled, a data collection system connected to the mud measurement system and the drilling measurement system configured to synchronously collect the measured one or more mud properties and measured one or more drilling parameters, and a data analysis system connected in real time to the data collection system.

Abstract: A method for operating a reservoir simulator includes performing a reservoir simulation based on a spatial reservoir model that represents a subterranean environment that includes a reservoir where, for a portion of the spatial reservoir model, the performing includes utilizing a phase model operational mode; based at least in part on a phase transition in the portion of the spatial reservoir model to a multi-phase region that includes a microemulsion, implementing a multi-phase operational mode; and, based at least in part on a phase transition in the portion of the spatial reservoir model from the multi-phase region to a different phase region, implementing the phase model operational mode for the portion of the spatial reservoir model.

Abstract: Systems and methods for optimized geosteering using real-time geological models that are updated with LWD measurements containing data such as, for example, layer boundaries and formation properties.

Abstract: An apparatus, system and/or method for making observations down a wellbore are provided. The wellbore observation system may comprise a mandrel that can be run downhole, and telescoping tracks can be utilized to move a camera and semi-conforming inflatable bladder out of the mandrel and into the wellbore. Once the bladder is inflated, it displaces high turbidity fluid in the wellbore to allow the camera to move about a track and observe the wellbore unobstructed. An alternative embodiment allows the mandrel and telescoping tracks to be utilized with other tools to perform cleaning, fishing, diagnostic, and analytic operations.

Abstract: Embodiments of the present disclosure are directed to a system that includes a cement plug and a sensor system. The sensor system includes a first sensor disposed within a tubular and configured to monitor a pressure within the tubular, a second sensor disposed within the tubular downstream of the first sensor with respect to a flow of fluid through the tubular, where the second sensor is configured to monitor the pressure within the tubular, and a controller configured to detect a launch of the cement plug when the first sensor detects a first pressure drop and when the second sensor detects a second pressure drop, where the second pressure drop occurs after the first pressure drop within a predetermined elapsed time range.

Abstract: A method for obtaining hydrocarbon from a reservoir in a subterranean formation is described. The method includes measuring a poromechanic pressure change due to lithostatic load sharing in the subterranean formation. Mapping the poromechanic pressure change to one or more locations in the subterranean formation. Identifying one or more local pressure peaks in the poromechanic pressure change, wherein the one or more local pressure peaks are each marked by a pressure escalation and subsequent pressure depletion. Determining a drained reservoir volume in the hydrocarbon reservoir based on the pressure escalation.

Abstract: A method includes receiving field measurement data of a plurality of well-pumps disposed respectively in a plurality of wells. The field measurement data are representative of speed data and run-time data of the plurality of well-pumps. The method further includes receiving commingled-flow measurement data. The commingled-flow measurement data are representative of a combined fluid flow data of the plurality of wells. The method further includes determining, by an optimizer unit, well-flow data of the plurality of wells based on the commingled-flow measurement data, the field measurement data, and a plurality of conservation constraints generated by a constraint generator. The well-flow data are representative of fluid flow data from each of the plurality of wells. The method also includes controlling operation of at least one of the plurality of well-pumps based on the well-flow data to control fluid production from the plurality of wells.

Abstract: A method and system of monitoring fluid flow in a wellbore (16). One or more space-distributed temperature input pulses (6a,b; 6?; 6?) are induced into at least a portion of the fluid in a housing (15; 15a,b; 15?; 15?) in the wellbore, The housing has at least one cavity (14; 14a,b) and one or more flow ports (4; 4?. 5; 5?; 5a?,b?). A temperature response pulse, caused by said temperature input pulses, are sensed at one or more locations (2) downstream of said cavity (14; 14a,b) and a flow rate of said fluid through said cavity (14) is determined. The flow rate may be determined based on one or more characteristics of said temperature response pulse, and the Retention Time Distribution (RTD) of said cavity.

Abstract: A borehole resistivity distribution system includes a cable having an array of transmitters along a shared conductive loop. Each of the transmitters is coupled to a corresponding frequency-dependent material or device. An application of a first drive signal to the cable excites the transmitters, to obtain a first measurement, the first drive signal having a first frequency and a first amplitude. An application of a second drive signal to the cable excites the transmitters, to obtain a second measurement, the second drive signal having a second frequency and a second amplitude. At least the first frequency is different from the second frequency, or the first amplitude is different from the second amplitude. The system further includes a processor coupled to receive the first and second measurements, to derive, based at least in part on the measurements, a resistivity distribution around a borehole.

Abstract: A method for obtaining hydrocarbon from a reservoir in a subterranean formation is described. The method includes measuring a poromechanic pressure change due to lithostatic load sharing in the subterranean formation. Mapping the poromechanic pressure change to one or more locations in the subterranean formation. Identifying one or more local pressure peaks in the poromechanic pressure change, wherein the one or more local pressure peaks are each marked by a pressure escalation and subsequent pressure depletion. Determining one or more regions in the reservoir exhibiting single phase hydrocarbon production.

Abstract: An engine block for an opposed-piston engine includes a first center section and a second center section. The first center section defines a first cylinder half bore having a first longitudinal axis and a first plurality of fastener bores. The second center section defines a second cylinder half bore having a second longitudinal axis and a second plurality of fastener bores that extend from a first end thereof to a second end thereof. The second center section is configured to abut the first center section such that: the first and second cylinder half bores are in fluid communication with one another to collectively form a single cylinder; the first and second longitudinal axes are offset from one another; and the first and second pluralities of fastener bores are aligned with one another for receiving a first plurality of fasteners to join the first and second center sections to one another.

Abstract: An opposed-piston engine includes an engine block, at least two intake valves, and at least two exhaust valves. The engine block includes a first center section and a second center section. The first center section defines a first cylinder half bore having a first longitudinal axis and a first open end. The second center section defines a second cylinder half bore having a second longitudinal axis and a second open end. The second longitudinal axis is offset from the first longitudinal axis. The first and second open ends overlap to form and opening therebetween that places the first and second cylinder half bores in fluid communication with one another to form a single cylinder. The intake valves are arranged at the first open end of the first cylinder half bore. The exhaust valves are arranged at the second open end of the second cylinder half bore.

Abstract: An engine comprises a compression portion and a combustion portion. The compression portion comprises twin-screw rotors, male engaged with female. The combustion portion comprises twin-screw rotors, male engaged with female. The male compression rotor and the male combustion rotor share a same longitudinal axis, and the female compression rotor and the female combustion rotor share a same longitudinal axis. A combustion plate is disposed between the compression portion and the combustion portion, and prevents flow of gas from the compression portion to the combustion portion, except through a small orifice centrally located on the combustion plate. A valve is affixed to the male rotors adjacent to the combustion plate, covering the lobes of the male rotors and extending beyond the lobes of the male rotors. The valve controls the flow of gas from the compression portion to the combustion portion.

Abstract: A method for manufacturing bladed rings for radial turbomachines, including: assembling a first support ring with a second support ring, with a plurality of blades, with a first and second connecting ring, to make a bladed ring including the first and second support ring coaxial and axially spaced and the plurality of blades disposed equidistant from a central axis and interposed between the rings. The method includes joining a first end of each blade to the first connecting ring, joining a second end of each blade to the second connecting ring, fixing the first connecting ring to the first support ring and fixing the second connecting ring to the second support ring. The first support ring, second support ring, plurality of blades, first and second connecting rings are finished elements before assembling, meaning they present their final geometry and need no further machining and/or plastic deformations during and/or after assembly.

Abstract: A power turbine includes a first stage vane having an airfoil with a cold nominal profile substantially in accordance with at least an intermediate portion of the Cartesian coordinate values of X, Y and Z set forth in Table 2. The X and Y values are distances, which when smoothly connected by an appropriate continuing curve, define airfoil profile sections at each distance Z. The profile sections at each distance Z are joined smoothly to one another to form a complete airfoil shape.

Abstract: A method for producing one or more cooling holes in an airfoil for a gas turbine engine is disclosed. The method includes casting one or more hole starter bosses on a suction side, a pressure side, or both of the airfoil, drilling the one or more cooling holes into the airfoil by way of the one or more hole starter bosses, and removing the one or more hole starter bosses after drilling the one or more cooling holes into the airfoil.

Abstract: A gas turbine blade includes a turbine blade having an outer surface divided according to surface sections arranged from a leading edge to a trailing edge; a plurality of film cooling holes formed in the outer surface, each film cooling hole including a cooling channel and an outlet communicating with the cooling channel to discharge cooling air to the outer surface; and a protrusion formed on an inside surface of the outlet of at least one film cooling hole disposed in exactly one surface section of the outer surface. The blade's outer surface is divided into three surface sections respectively corresponding to thirds of a length of the outer surface, from the leading edge to the trailing edge, and including first and third surface sections adjacent to the leading and trailing edges, respectively, and a second surface section in which the protrusion occurs between the first and third surface sections.

Abstract: The invention relates to a turbomachine turbine vane comprising a root having a blade (12) comprising a leading edge (16) and a trailing edge (17) and a lower surface wall (14) and an upper surface wall (13), as well as: a manifold for cooling (18) the leading edge (16); a supply line (19) for collecting air from the root and supplying the manifold (18); a side cavity (23) extending along the upper surface wall (13) and supplied with air from the root, to form a heat shield facing the supply line (19); and a circuit forming a trombone comprising a middle portion (24) extending along the supply line (19) and extending laterally to the upper surface wall (13), the middle portion (24) being supplied by the supply line at the tip of the blade (12).

Abstract: A gas turbine includes a housing; a rotor rotatably provided in the housing; a turbine blade to receive rotating force from combustion gas and rotate the rotor; a turbine vane to guide a flow of the combustion gas toward the turbine blade, the turbine vane having a turbine vane cooling passage for delivering cooling fluid to an inner wall of the turbine vane; and an impingement plate installed in the turbine vane cooling passage, the impingement plate having a plurality of injection holes through which the cooling fluid is injected onto the inner wall of the turbine vane, the injection holes formed at predetermined locations of the impingement plate, wherein the injection holes are formed differently depending on locations of the injection holes. A temperature gradient or thermal stress may be prevented from occurring in the turbine vane that is cooled by cooling fluid ejected from the impingement plate.

Abstract: A turbine airfoil (10) includes a flow blocking body (26) positioned an internal cavity (40). A first near-wall cooling channel (72) is defined between the flow blocking body (26) and an airfoil pressure sidewall (16). A second near-wall cooling channel (74) is defined between the flow blocking body (26) and an airfoil suction sidewall (18). A connecting channel (76) is defined between the flow blocking body (26) an internal partition wall (24) that connects the airfoil pressure (16) and suction (18) sidewalls. The connecting channel (76) is connected to the first (72) and second (74) near-wall cooling channels along a radial extent. Turbulating features (90, 90a-b) are located in the connecting channel (76) and are formed on the flow blocking body (26) and/or on the partition wall (24). The turbulating features (90, 90a-b) are effective to produce a higher coolant flow rate through the first (72) and second (74) near-wall cooling channels in comparison to the connecting channel (76).

Abstract: There is a described an aerofoil component for a turbomachine, the aerofoil component comprising: a central core formed from a metal matrix composite; and an external layer comprising a pressure surface, a suction surface, a leading edge, a trailing edge and a root, the external layer being formed by a metal which covers the metal matrix composite of the central core. Also described is a method of manufacturing such an aerofoil component.

Abstract: The present disclosure is directed to an outer drum rotor assembly for a gas turbine engine including a first outer drum and a second outer drum. Each outer drum defines a radially extended flange adjacent to one another. A plurality of outer drum airfoils is extended inward along the radial direction from between the first outer drum and the second outer drum at the flange.

Abstract: An airfoil assembly includes at least one airfoil that has a hollow interior. First and second platforms are disposed between the airfoil. At least one tie-spar extends along an axis through the first platform, the hollow interior of the airfoil, and the second platform. There is a thermal expansion difference between a thermal expansion of the tie-spar in the axial direction and the combined thermal expansion of the airfoil and the first and second platform in the axial direction. At least one spacer portion is arranged on the tie-spar. The spacer portion has a thermal expansion in the axial direction that is greater than the thermal expansion difference such that the spacer portion maintains the tie-spar under tension and clamps the first and second platforms on the airfoil.

Abstract: Borescope plugs are described. The borescope plugs include a borescope plug base having a first side configured to support a shank and a second side having a centroid defined as the center of the borescope plug base, a first mounting aperture formed in the second side, and a second mounting aperture formed in the second side. The first and second mounting apertures are configured to each receive a fastener to mount the borescope plug base to a case, and an offset line drawn through the center of the first mounting aperture and through the center of the second mounting aperture does not pass through the centroid or does not include a point defined by the centroid.

Abstract: A non-metallic engine case inlet compression seal for a gas turbine engine includes a non-metallic longitudinal leg section that extends from the non-metallic arcuate interface section and a non-metallic mount flange section that extends from the longitudinal leg section.

Abstract: A seal structure for a gas turbine blade including a shank including a first side surface, a second side surface, and a bottom surface located radially inward from a fin. The first side surface has a recess movably housing a wedge seal, and a slot on the bottom surface as an insertion opening for a spline seal. The second side surface has a slot on the bottom surface as the insertion opening. The recess has an inclined surface extending straight radially inward and away from the first side surface. The wedge seal includes a wedge portion including a first wedge surface to be opposed to the inclined surface and a second wedge surface to be opposed to the second side surface of the adjacent rotor blade to form a wedge together with the wedge surface, and a weight portion positioned radially inward in the recess from the wedge portion.

Abstract: Labyrinth seal for a turbine engine, in particular of an aircraft, including a rotor element rotating about an axis of rotation (A), and a stator element extending around the rotor element, the rotor element including a series of annular lip(s) extending radially outwards and surrounded by at least one abradable element carried by the stator element, each lip including an inner peripheral body portion, an outer peripheral body portion (12b) and an upstream annular face for impact of an air flow during operation, wherein at least one lip has, looking from the upstream annular face, a first annular cavity with a concave rounded cross-section on its inner peripheral body portion and a second annular cavity with a concave rounded cross-section on its outer peripheral body portion.

Abstract: A seal assembly includes a side ring and a cartridge. The side ring comprises an annular piece of solid material. The cartridge is affixed to the side ring and comprises a shoulder, a beam connected to and extending from the shoulder, a shoe attached to an end of the beam, and a rotary seal disposed on a bottom portion of the shoe.

Abstract: An aspirating face seal between high and low pressure regions of a turbomachine at a juncture between rotatable and non-rotatable members of turbomachine includes gas bearing rotatable and non-rotatable face surfaces. Starter seal tooth and optional deflector seal tooth are mounted on seal teeth carrier on rotatable member. Primary seal tooth and non-rotatable face surface are mounted on an annular slider on non-rotatable member. Pull-off biasing means urges the annular slider away from the rotatable member and the non-rotatable face surface away from the rotatable surface. A secondary seal is in sealing engagement with the annular slider in the low pressure region and pull-off biasing means is located radially outwardly of the annular slider in the high pressure region. Biasing means may include coil springs within spring chambers of circumferentially spaced cartridges. Tongues extend inwardly from spring chambers into grooves in slider.

Abstract: An article for use in a high-temperature environment that includes a substrate including a superalloy material, a ceramic, or a ceramic matrix composite, and an abradable coating on the substrate, the abradable coating including a rare earth silicate and a dislocator phase, the dislocator phase forms one or more distinct phase regions in the abradable coating and comprises at least one of hafnium diboride (HfB2), zirconium diboride (ZrB2), tantalum nitride (TaN or Ta2N), tantalum carbide (Ta2C) titanium diboride (TiB2), zirconium carbide (ZrC), hafnium carbide (HfC), tantalum diboride (TaB2), hafnium nitride (HfN), or niobium carbide (NbC).

Abstract: An article includes a substrate, a bond coat on the substrate, and a multilayer environmental barrier coating (EBC) on the bond coat. The multilayer EBC includes a first EBC layer defining a first thickness and a second EBC layer defining a second thickness. The first EBC layer includes a first rare earth disilicate and a first concentration of a sintering aid that includes alumina. The second EBC layer includes a second rare earth disilicate and a second concentration of the sintering aid that includes alumina, less than the first concentration of the sintering aid.

Abstract: A system may include a component including a substrate and a non-continuous abradable coating on the substrate. The non-continuous abradable coating may include a plurality of respective physical segments. Each respective physical segment may be separated from an adjacent respective physical segment by a respective channel. A respective width of the respective channel between each respective segment and the adjacent respective segment may be greater than a combined maximum thermal expansion of the respective physical segment and the adjacent respective segment toward each other at a maximum design temperature of the component.

Abstract: A tip sealing structure for a blade includes a casing having an inner circumferential surface facing the blade; a blocking groove formed in the inner circumferential surface of the casing; and a movable seal provided on a tip of the blade and configured to move in a depth direction of the blocking groove. Since the seal is configured to move into the blocking groove, tighter sealing at the tip of the blade can be accomplished. A seal bracket of the moveable seal encloses a movement space open at one end and includes a seal stop formed at the open end. A brush body including top and bottom crossbars is disposed partially within the seal bracket, such that movement of the moveable seal is limited by the bottom crossbar being stopped by the seal stop. A first brush seal is mounted on the brush body and positioned in the blocking groove.

Abstract: A stop valve includes a connection-switching part capable of switching a connection state between a rod part having an end portion which is connected to a valve disc and an actuator part which linearly moves the rod part. The connection-switching part includes a concave engaging part which is recessed the rod part, a casing having an accommodation space joined to the concave engaging part formed therein, a plurality of frame pieces, a sleeve part which is movable between the frame piece accommodation position and a frame piece detachment position, and a gas introduction part through which a gas is introduced into the accommodation space. The sleeve part moves from the frame piece detachment position to the frame piece accommodation position using the gas. The casing is in contact with the frame pieces at the frame piece accommodation position when moving toward the second side in the central axis direction.

Abstract: A method and apparatus for rigging a variable stator vane arrangement (100) for a gas turbine engine (10) is provided. The arrangement provides at least two sets of rigging holes to an actuator (200), with the actuator extension during rigging being dependent on which of the sets of holes are aligned. This allows the actuator extension to be adjustable during rigging, thereby facilitating different relationships between actuator extension and variable vane angle in use.

Abstract: A fan for a gas turbine engine is provided. The fan includes a plurality of fan blades, a disk, and a trunnion mechanism for attaching the fan blades to the disk. The disk can be formed of a plurality of individual disk segments, with the trunnion mechanism attaching one of the plurality of fan blades to a respective disk segment. A retention member is also provided. The retention member includes a means for catching a portion of the trunnion mechanism should a primary attachment system of the trunnion mechanism fail.

Abstract: A gas turbine engine, comprising a fan driven by a fan shaft and retractable axial retainer of the shaft mounted on a stator element and movable between a first operational position and a second non-operational position. The retainer may comprise a fluid supply configured for supplying at least one cavity with fluid. In some examples, the retainer is mounted movable or slidingly so as to generate movement of the retainer between the operation and non-operational positions.