Abstract: A downhole valve has a housing with a longitudinal main passage and at least one valve port extending from the main passage and through the housing, a valve member is arranged in the main passage, the valve member arranged to cover the at least one valve port, wherein at least a part of the valve member is made of a degradable material which is reactive to water or a well fluid, and has a surface coating of a material which is non-reactive to water or the well fluid.

Abstract: A barrier is provided in a tubular string for opening up the top of the well for drilling or completion applications. In applications where two barriers are required due to regulations a control line actuated safety valve could serve as a first barrier which a flapper is held open by a first sleeve with a seat. Another barrier (disclosed here) actuated by a first object landing on a seat to force the sleeve away from the flapper to allow the flapper to close to serve as a second barrier. After the top of the well is reclosed after being open a second object engages a seat on a second sleeve to push the flapper back to open and to lock the flapper in the open position. The objects degrade or are blown through the seats leaving the tubular passage open for the passage of tools or production flow.

Abstract: The invention relates to a multi-stage hydraulic fracturing tool and system for controllably exposing selected locations along a wellbore to a pressurized fluid. The system comprises an elongated casing (for disposal within the wellbore) defining an internal borehole extending longitudinally, and having one or more ports; an actuation member configured for travelling down the borehole and includes a wedged portion and a groove having a first length in the longitudinal direction, formed at least partially circumferentially around an outer surface of the actuation member, a sliding sleeve member having an aperture for receiving the actuation member, and one or more inward-facing protrusions having a length less than or equal to the first length, connected to the sliding sleeve member and at least initially protruding radially into the aperture.

Abstract: The invention relates to a multi-stage hydraulic fracturing tool and system for controllably exposing selected locations along a wellbore to a pressurized fluid. The system comprises an elongated casing (for disposal within the wellbore) defining an internal borehole extending longitudinally, and having one or more ports; an actuation member configured for travelling down the borehole and includes a wedged portion and a groove having a first length in the longitudinal direction, formed at least partially circumferentially around an outer surface of the actuation member, a sliding sleeve member having an aperture for receiving the actuation member, and one or more inward-facing protrusions having a length less than or equal to the first length, connected to the sliding sleeve member and at least initially protruding radially into the aperture.

Abstract: A fracturing valve comprising a tubular mandrel having a through bore continuous with a tubing string, and a frac window through the side of the tubular mandrel. An outer sleeve is radially disposed around the tubular mandrel. The outer sleeve includes a sleeve port in a sidewall. The tubular mandrel slides relative to the sleeve by application and release of set down weight on a coiled tubing string. When the valve is closed, there is no fluid communication from the tubing string out of the frac window. When the valve is open, fluid communication from the tubing string is enabled. The valve may be installed in a downhole tool having a perforation device. The tool string can be used with one sealing element as the tool is pulled up the hole isolating lower perforations, or with two sealing elements to allow pin-point treatments isolating perforations both up and downhole.

Abstract: A subassembly for a bottom hole assembly of a drill string, the subassembly comprising: a tubular portion having a wall for supporting one or more sensors and an inner surface defining a longitudinal bore; a probe assembly comprising a main body, the probe assembly being removably located in the bore and positioned such that a flow channel for drilling fluid is defined between the inner surface of the tubular portion and the probe assembly. A communications link for data transfer between the probe assembly and a sensor supported by the tubular portion.

Abstract: The present disclosure provides a system, method and apparatus for the removal of natural gas/methane from in situ loci within shale reservoirs to (i) provide fully de-carbonized surplus electricity, and (ii) power re-injection of the resulting carbon formed (CO2) upon combustion in an electric generator along with large volumes of atmospheric CO2, such as for large scale removal of CO2 from the Earth's surface/atmosphere.

Abstract: A subassembly for a bottom hole assembly of a drill string, the subassembly comprising: a tubular portion having a wall for supporting one or more sensors and an inner surface defining a longitudinal bore; a probe assembly comprising a main body, the probe assembly being removably located in the bore and positioned such that a flow channel for drilling fluid is defined between the inner surface of the tubular portion and the probe assembly. A power link for transferring electrical power between the probe assembly and a sensor supported by the tubular portion.

Abstract: A system includes a schedule generator having one or more processors configured to obtain resource extraction parameters for extracting a resource from a reservoir. The resource extraction parameters include well creation parameters associated with drilling wellbores, well stimulation parameters associated with introducing fracturing fluid into the wellbores, and production parameters associated with extracting the resource through the wellbores. The schedule generator selects initial trial schedules having different values of the resource extraction parameters and receives initial resource output data generated by execution of the initial trial schedules with a designated reservoir model. The schedule generator generates a surrogate model based on the initial resource output data and the initial trial schedules and uses the surrogate model to perform iterations of selecting modified trial schedules until a predetermined condition is satisfied.

Abstract: A method for modeling a reservoir includes receiving vertical formation data describing geological formations in a vertical direction as a function of vertical depth, receiving near-wellbore horizontal formation data describing the geological formations in a horizontal or deviated direction near a wellbore up to a wellbore instrument range, and correlating the vertical formation data with the near-wellbore horizontal formation data to create horizontally adjusted formation data to describe the geological formations in the vertical direction beyond the wellbore instrument range, along the horizontal or deviated direction.

Abstract: A method of performing oilfield operations at a wellsite is disclosed. The wellsite is positioned about a subterranean formation having multiple wellbores therethrough and a fracture network therein. The fracture network includes natural fractures. The method involves generating fracture parameters including a hydraulic fracture network of a fracture grid for each of the multiple wellbores based on wellsite data including microseismic events and a mechanical earth model, generating reservoir parameters including an updated mechanical earth model of a reservoir grid based on the wellsite data and the fracture parameters, generating integrated wellsite parameters including an integrated earth model by integrating the fracture parameters from the multiple wellbores with the reservoir parameters, and performing production operations at the multiple wellbores based on the integrated wellsite parameters.

Abstract: A method of performing a fracture operation at a wellsite is disclosed for a wellsite positioned about a subterranean formation having a wellbore therethrough and a fracture network therein. The fracture network includes natural fractures. The method involves generating wellsite parameters of the wellsite comprising seismic measurements, generating smooth fracture parameters of a smooth fracture by solving governing equations based on the wellsite parameters, and generating ledged fracture parameters of a ledged fracture by identifying ledge locations and generating ledged fracture parameters of a ledged fracture at the ledge locations by solving the governing equations based on the wellsite parameters for the ledge locations.

Abstract: A method of performing oilfield operations at a wellsite is disclosed. The wellsite is positioned about a subterranean formation having a wellbore therethrough and a fracture network therein. The fracture network includes natural fractures. The method involves generating fracture parameters including a hydraulic fracture network based on wellsite data including a mechanical earth model, generating reservoir parameters including a reservoir grid based on the wellsite data and the generated fracture wellsite parameters, forming a finite element grid from the fracture and reservoir parameters by coupling the hydraulic fracture network to the reservoir grid, generating integrated geomechanical parameters including estimated microseismic events based on the finite element grid, and performing fracture operations and production operations based on the integrated geomechanical parameters.

Abstract: Well management includes receiving, from a user computing system, a simulation job request for simulating well management on the cloud computing system including compute nodes, and obtaining, for the simulation job request, search spaces for completion stage simulations, fracture stage simulations, and production stage simulations. Well management further includes orchestrating, using the search spaces, the completion stage simulations, the fracture stage simulations, and the production stage simulations on the cloud computing system to obtain at least one optional well plan, and sending the at least one optional well plan to the user computer system.

Abstract: A monitoring system may include a position sensor, strain gauges, and a computing device for monitoring valves in a pressure pump having multiple chambers to determine critical valve limits for the valves using strain measurements for each charmber. The strain gauges may determine strain in each chamber of the pressure pump. The position sensor may determine the position of a crankshaft mechanically coupled to a plunger in each chamber. The computing device may receive signals generated by the strain gauges and the position sensor related to the strain in each chamber and the position of the crankshaft, respectively, and may process the signals to determine delays in the actuation of the valves for determining critical valve limits.

Abstract: A method of electrically enhancing oil-recovery from an underground oil-bearing reservoir (3), comprising: (a) selecting an underground rock formation (2) comprising an oil-bearing reservoir (3); (b) positioning two or more electrically conductive elements (4, 5) at two or more spaced apart locations in proximity to said formation (2, 3), at least one of said conductive elements (4, 5) being disposed in or adjacent to a bore hole affording fluid communication between the interior of said bore hole and said formation; (c) imposing a controlled electrical charging potential between said two or more electrically conductive elements (4, 5) for a charging time sufficient to cause a capacitive charging of said formation to an operating charging potential; (d) lowering or maintaining said charging potential below 40 mV per miming meter between said two or more electrically conductive elements (4, 5); and (e) withdrawing oil from at least one of said bore holes.

Abstract: Additional oil recovery is obtained from a reservoir with a composition comprising at least a coupling solvent typically employed in waterborne coating compositions. Provided herein are embodiments of methods of recovering hydrocarbons using at least one coupling solvent, such as an oxygenated coupling solvent. The coupling solvent increases the mutual solubility with water at the injection temperature to facilitate the mixing and injection, particularly with an optional co-solvent. The coupling solvent helps mitigate formation plugging and improve performance when injected into a formation, as the solvent mixture moves from being miscible in the injection field water to being miscible in the reservoir oil, mobilizing the reservoir oil to increase oil recovery.

Abstract: A method of enhancing conductivity within a hydrocarbon-bearing reservoir by building proppant pillars in a spatial arrangement in fractures created or enlarged in the reservoir. Two fluids of differing stability are simultaneously pumped into the reservoir. The fluids may contain identical proppant mixtures which include a first proppant which has an apparent specific gravity less than the apparent specific gravity of a second proppant. The fluids may contain identical proppants mixtures where the average particle size of a first proppant is greater than the average particle size of a second proppant. Vertically extending pillars are created within the formation when the fluids are destabilized and the first proppant is then released from the destabilized fluids. The area between the pillars may be held open by the presence of the second proppant in the remaining fluid.

Abstract: A slurry injection system has a plurality of slurry valves fluidically coupled to first and second elongated tanks. In the first state, the slurry valves communicate high pressure slurry from the second volume to a site and communicate low pressure slurry to the fourth volume. In the second state, the slurry valves communicate low pressure slurry to the second volume and high pressure slurry from the fourth volume to the slurry injection site and in the intermediate state communicating high pressure slurry simultaneously from the first elongated tank and the second elongated tank to the slurry injection site. In the first state clear fluid valves fluidically communicate high pressure clear fluid to the first volume and low pressure clear fluid from the third volume and, in a second state, communicate low pressure clear fluid from the first volume and high pressure clear fluid to the third volume.

Abstract: Natural gas dissolved in saline ground water can be recovered for use. The process includes the pumping of water production wells, separation of gas and water at the surface, gas compression, desalination of ground water, and injection of excess water into disposal wells. A definitive test of the process was completed on Jan. 9 and 10, 2013, at Gill Ranch Gas Field, California: volumes of recovered gas were equal to predictions based on methane solubility. Analyses of the gas showed that it was equal in heat value (about 975 BTU per cubic foot) to dry gas produced from the same field. Saline water recovered during the full scale test was returned to the same aquifer from which it was produced.

Abstract: A method of determining information inside a borehole is provided. The method includes the use of a ferrofluid seal to seal a rotating shaft used in the borehole. In preferred embodiments, the method comprises: selecting at least one sensor to be lowered into the borehole; coupling the sensor to the end of a rotating shaft; running the rotating shaft through a housing including a plurality of bearings and an oil reservoir, sealing a downhole end of the housing from an exterior of the housing with a ferrofluid seal; and forcing the sensor, rotating shaft, housing, bearings, oil reservoir, and ferrofluid seal into the borehole to make a measurement.

Abstract: A wellbore tool includes a cooling section positioned within the tool for the purpose of maintaining the temperature sensitive components within their rated operating temperature range. The cooling section includes an evaporator, compressor, condenser, power device, expansion device. The compressor is positioned within the condenser. The components whose temperatures are to be maintained are in thermal contact to the evaporator. The cooling process is based upon the vapor compression cycle.

Abstract: The structural integrity and reliability of a downhole tool or mandrel may be improved by implementation of a design and configuration that does not require several separate components to be coupled together. An insulating sleeve is wrapped around the outside of a mandrel. Electrodes, both transmit and return, are wrapped around the insulating sleeve. The outside diameter of the mandrel is increased but the structural integrity and reliability of the mandrel is maintained as no gap sub is used to electrically isolate the electrodes from the mandrel. The insulating sleeve may be tapered at the edges to prevent excessive wear on the sleeve. The insulating sleeve may also extend the full distance between the electrodes to provide even more insulation.

Abstract: A method for in-situ determination of a wellbore formation pressure through a layer of cement, the method includes detecting an output pressure signal from a pressure sensor disposed in a housing in the cement outside a wellbore casing; detecting a first temperature signal from a first temperature sensor disposed in the housing; and calculating a temperature compensated output pressure signal based on the output pressure signal and the first temperature signal.

Abstract: The operational position of a moveable device is detected using an electromagnetic induction logging tool. The logging tool generates a baseline log of the moveable device in a non-actuated position, and a response log of the moveable device in an actuated position. The baseline and response logs are then compared in order to determine the operational position of the moveable device.

Abstract: The subject technology relates to estimation of flow rates using acoustics in a subterranean borehole and/or formation. Other methods, systems, and computer-readable media are also disclosed. The subject technology includes drilling a wellbore penetrating a subterranean formation. The subject technology includes logging the wellbore using an acoustic sensing tool to obtain logged measurements, and obtaining acoustic pressure data associated with a leak source in the wellbore using the logged measurements. The subject technology also includes determining a flow rate (volumetric for fluid-based or mass for gas-based) of the leak source from the acoustic pressure data, and determining an area of the leak source from the determined flow rate. The subject technology also includes generating and providing, for display, a representation of the leak source using the flow rate and the area of the leak source.

Abstract: An apparatus and method for pressure testing a tubing string of a fluid production well, the tubing string being provided with a progressing cavity pump at a downhole end, which apparatus and method can be used to help determine whether the tubing string has failed or the pump has failed. The apparatus comprises a plug member connected to the rod string assembly that includes the pump rotor, such that the rod string assembly can be lowered to seat the plug member in a seat member within the tubing string above the pump, thus sealing off and isolating the pump from the rest of the tubing string, allowing pressure testing of the tubing string above the pump.

Abstract: Systems, methods and apparatuses for communication between a surface of a wellbore and a downhole location of a wellbore via acoustic waveguide transfer. A first device can transmit an acoustic signal through a wellbore waveguide that is coupled with the first device. The acoustic signal can transfer from the wellbore waveguide to a wellbore tubular through a contact between the wellbore waveguide and the wellbore tubular. A second device can receive the acoustic signal via the wellbore tubular that is coupled with the second device.

Abstract: A rotary pulser for transmitting information in a mud pulse telemetry system of a drilling operation. The pulser has two rotors mounted adjacent each other so that obstruction of the passages formed between the blades in one pulser by the blades of the other pulser creates pressure pulses in the drilling fluid. Each rotor is separately controlled and can be rotated continuously in one direction or oscillated. The ability to rotate each rotor separately provides flexibilty in the pulser's operating mode, so as to allow more efficient generation of pulses, and also enhances the ability of the pulser to clear debris that would otherwise jam or obstruct the pulser.

Abstract: A friction bolt assembly includes: an expansible sleeve having a tubular body between leading and trailing ends, which body has a longitudinally extending formation about which the body resiliently deforms and which formation extends along at least part of the body, ending at the body leading end; a rod extending through the sleeve body and between first and second ends and on which a projecting part is defined between the trailing end of the sleeve body and the second end; an expansion element on the rod at the first end; a first load bearing formation on the projecting rod part, moveable along the projecting part to abut the sleeve trailing end; a load applicator on the projecting part of the rod; and a second load bearing formation mounted over the projecting part of the rod between the first load bearing formation and the load applicator unit.

Abstract: A power system including a pump drive having a first side and a second side, a motor that is operationally connected to the first side of the pump drive, an engine that is operationally connected to the second side of the pump drive, and a pump that is operationally connected to the pump drive. The preferred power system is adapted to power the item of equipment with either the motor or the engine. A method for providing power to an item of equipment by engaging the pump drive with the engine and/or the motor.

Abstract: Disclosed is a vane pump comprising a cam ring accommodated in a pump housing, a rotor accommodated rotatably with respect to a rotational shaft in the cam ring, and a plurality of vanes coupled to the rotor to discharge fluid, wherein the cam ring has a ring shaped inner profile varied between a maximum radius (Rmax) and a minimum radius (Rmin) in a circumferential direction with respect to the rotational shaft, and the ring shaped inner profile comprises: a cycloid curve passing through a maximum radius point; a circular arc passing through a minimum radius point; and a tangent line connecting the cycloid curve to the circular arc with a tangential curvature.

Abstract: The present disclosure provides devices and methods related to rotor disk bosses. For example, a rotor disk assembly comprises a first rotor disk, wherein the first rotor disk comprises a web, disposed between a rim and a bore. The rotor disk assembly further comprises a second rotor disk operatively coupled to the first rotor disk, an inter-disk device disposed on the second rotor disk and extending axially toward the first rotor disk, and a boss disposed on the first rotor disk, wherein the boss protrudes axially from the web toward the inter-disk device.

Abstract: The present disclosure is directed to a gas turbine engine defining a radial direction, a circumferential direction, an axial centerline along a longitudinal direction, and an upstream end and a downstream end along the longitudinal direction. The gas turbine engine defines a core flowpath extended generally along the longitudinal direction. The gas turbine engine includes a first turbine rotor. The first turbine rotor includes an annular outer band disposed outward of the core flowpath along the radial direction. The first turbine rotor further includes a plurality of airfoils coupled to an inner diameter of the outer band in which the plurality of airfoils are extended generally inward along the radial direction. The outer band defines a plurality of airfoil cooling passages in which the plurality of airfoil cooling passages are extended at least partially in the radial direction in fluid communication with the plurality of airfoils.

Abstract: A turbine blade includes an airfoil that includes a root end and a tip end. The tip end is radially spaced from the root end. A tip shroud extends from the tip end. The tip shroud includes a shroud plate. The shroud plate includes a plurality of undulating ridges.

Abstract: When cold and in the non-coated state, the aerodynamic profile is substantially identical to a nominal profile determined by the Cartesian coordinates X,Y, Zadim given in Table 1, in which the coordinate Zadim is the quotient D/H where D is the distance of the point under consideration from a first reference plane P0 situated at the base of the nominal profile, and H is the height of said profile measured from the first reference plane to a second reference plane P1. The measurements D and H are taken radially relative to the axis of the turbine, while the X coordinate is measured in the axial direction of the turbine.

Abstract: When cold and in the non-coated state, the aerodynamic profile is substantially identical to a nominal profile determined by the Cartesian coordinates X,Y, Zadim given in Table 1, in which the coordinate Zadim is the quotient D/H where D is the distance of the point under consideration from a first reference plane P0 situated at the base of the nominal profile, and H is the height of said profile measured from the first reference plane to a second reference plane P1. The measurements D and H are taken radially relative to the axis of the turbine, while the X coordinate is measured in the axial direction of the turbine.

Abstract: When cold and in the non-coated state, the aerodynamic profile is substantially identical to a nominal profile determined by the Cartesian coordinates X, Y, Zadim given in Table 1, in which the coordinate Zadim is the quotient D/H where D is the distance of the point under consideration from a first reference plane P0 situated at the base of the nominal profile, and H is the height of said profile measured from the first reference plane to a second reference plane P1. The measurements D and H are taken radially relative to the axis of the turbine, while the X coordinate is measured in the axial direction of the turbine.

Abstract: An interlocking modular airfoil for a turbine. The airfoil includes at least one support column extending from a lower plate and at least one first filament having at least one first side aperture that receives the support column in a first transverse direction. The airfoil also includes at least one second filament having at least one second side aperture that receives the support column in a second transverse direction, wherein the second filament includes a flange for covering the first side aperture. In addition, the airfoil includes a cooling channel extending through the support column, wherein the support column includes apertures for emitting a cooling fluid transmitted via the cooling channel for cooling the first and second filaments. Further, the airfoil includes an upper plate located on top of the first and second filaments for maintaining the first and second filaments under compression.

Abstract: A component for a gas turbine engine including a body having at least one internal cooling cavity and a plurality of film cooling holes disposed along a first edge of the body. At least one of the film cooling holes includes a metering section defining an axis, and a diffuser section having a centerline. The centerline of the diffuser section is offset from the axis of the metering section.

Abstract: An apparatus and method for an engine component for a turbine engine including an exterior wall separating a hot fluid flow exterior of the engine component from a cooling fluid flow interior of the engine component. A cooling circuit can be provided within the component having a cooling passage. At least two film holes can extend through the exterior wall for providing a cooling film along the exterior of the wall. The film holes can overlap one another relative to the hot fluid flow.

Abstract: In one aspect, the present disclosure is directed to a rotor blade for a turbomachine. The rotor blade includes an airfoil defining at least one cooling passage. The rotor blade also includes a tip shroud coupled to the airfoil. The tip shroud and the airfoil define a core fluidly coupled to the cooling passage. A maximum radial depth of the core is at least six times greater than a minimum hydraulic diameter of a largest cooling passage of the at least one cooling passage.

Abstract: An airfoil may comprise an airfoil body having a leading edge, a trailing edge, an inner diameter end wall and an outer diameter end wall. A first cooling structure may be disposed within the airfoil body. The first cooling structure may comprise a first rib extending between the inner diameter end wall and the outer diameter end wall and may define a first radial passage configured to conduct a cooling airflow in a radial direction through the airfoil body. A second cooling structure may be disposed within the airfoil body. The second cooling structure may comprise a first baffle defining an axial passage configured to conduct the cooling airflow in an axial direction toward the trailing edge of the airfoil body.

Abstract: A cooling circuit for a trailing edge region of a turbine airfoil where the trailing edge is relatively thin, the cooling circuit having a series of aftward flowing channels alternating with a series of forward flowing cooling channels, and a turn channel at the trailing edge of the airfoil where the aftward flowing channels flow into the forward flowing channels in order to keep the airfoil thin and to provide cooling to the thin trailing edge. Spanwise extending cooling supply channels and cooling return channels are connected to the aftward and forward flowing channels and positioned to allow for a thinner airfoil.

Abstract: A turbine blade includes an airfoil that extends from a root end to a tip end, and a tip shroud extending from the tip end. The tip shroud includes a shroud plate that includes a pressure side edge. The pressure side edge includes a primary contact surface configured to couple against an adjacent tip shroud, and a notch extending at least partially downstream from the primary contact surface.

Abstract: A method for modifying an airfoil shroud located at a tip of an airfoil is provided. A locating step locates a reference location in a first end edge. The reference location includes a portion of a fillet. A seal rail extends circumferentially along a radially outer surface of the airfoil shroud. The fillet extends along the radially outer surface and is positioned directly adjacent to the seal rail. A forming step forms a compound relief cut in the fillet without performing a weld process on the airfoil shroud to remove the reference location. The compound relief cut has a first cut having a first radius extending from the seal rail towards the first end edge, and a second cut having a second radius extending from an end of the first cut to the first end edge. Modifying the airfoil shroud is complete following forming the compound relief cut.

Abstract: A rotor assembly includes plural blades and damping inserts. The blades include a carrier shroud and a lid shroud extending from an airfoil of the respective blade in generally opposite directions. The carrier shrouds define pockets at distal ends thereof. The damping inserts are disposed in the pockets of the carrier shrouds of the blades and free-floating within the pockets. The damping inserts are configured to dampen vibrations of the blades during rotation of the blades and the rotor disk via engaging an interior surface within the corresponding pocket of the carrier shroud and engaging a distal end of the lid shroud of the neighboring blade. A contact force applied by each damping insert on the distal end of the lid shroud of the neighboring blade is based on a rotational speed of the blades and the rotor disk.

Abstract: A turbine blade includes an airfoil that extends from a root end to a tip end, and a tip shroud extending from the tip end. The tip shroud includes a shroud rail that includes a series of regions along a circumferential width of the shroud rail. The series of regions includes a first edge region adjacent to a suction side edge of the tip shroud, and a wide region. A thickness of the wide region is greater than a thickness of the first edge region.

Abstract: A turbine blade includes an airfoil that extends radially between a root end and a tip end, a platform coupled to the root end, and a shank that extends radially inwardly from the platform. The shank includes a cover plate. The cover plate includes an outer surface, an opposite inner surface, and a contoured face that at least partially defines a damper pin slot. The contoured face extends from the outer surface to a first blend edge. The cover plate also includes a blended surface that extends from the first blend edge to a second blend edge. The second blend edge intersects with the inner surface.

Abstract: A turbine blade includes an airfoil that extends from a root end to a tip end. A tip shroud extends from the tip end. The turbine blade further includes a pressure side fillet. The pressure side fillet couples the tip end to the tip shroud. The pressure side fillet includes a first protrusion located adjacent to the tip end and a second protrusion located radially inward from the first protrusion.