Abstract: A portable mast assembly is comprised of a skid assembly having a horizontally oriented frame having longitudinally extending support surfaces and a mast assembly having at least two vertically extending column assemblies that are supported upon one or more longitudinally extending mast supports. A means for moving the one or more mast supports along the extending support surfaces of the frame is provided.

Abstract: A solid-state hydrophone may include a piezoelectric rod positioned between at least two electrodes. The piezoelectric rod may be disposed within a metallic housing to shield the piezoelectric rod and its connections from acoustic and electromagnetic waves. The piezoelectric rod and the electrodes may be potted in the mechanical housing using a potting material that may be positioned adjacent to the piezoelectric rod. At least a layer of the potting material may be positioned between the piezoelectric rod and the metallic housing to physically separate the piezoelectric rod from the metallic housing.

Abstract: A seal assembly includes a housing at least partially defining a seal opening and at least partially surrounding a rotatable shaft. A carbon seal is located at least partially in the seal opening and includes a sealing surface. The rotatable shaft includes a radially facing surface that has a carbide based coating and a diamond-like carbon coating in engagement with the sealing surface on the carbon seal.

Abstract: The invention relates to reamers used in downhole oil well drilling operations, particularly in reaming while drilling applications. Presented is a reamer having an interior channel which runs along an elongate axis of the entire body of the reamer, wherein there are openings along both ends of the reamer, exposing the interior channel. Additionally presented in the reamer are a plurality of paths extending parallel to the interior channel along the exterior of the body of the reamer, and running in a helical pattern along the entirety of the exterior of the body of the reamer. Disposed within the helical paths are a plurality of cutting inserts, which cutting inserts are enabled to provides a uniform cutting surface against a well bore, which preferably improves cutting action and reduces strain on the reamer.

Abstract: A sensor apparatus is provided for transmitting data of a polished rod in a rod pumping system, the rod pumping system including a rod rotator that rotates the polished rod. The sensor apparatus includes an outer shell configured to receive the polished rod, a signal processor within the outer shell, a position sensor within the outer shell and configured to sense and output to the signal processor a position signal, and a magnetic pickup sensor configured to sense and output to the signal processor a signal indicating a sensed magnetic field. The signal processor is configured to count a number of strokes of the polished rod based on the position signal, and to determine whether a fault exists based on the number of strokes and the signal indicating the sensed magnetic field.

Abstract: An agitator for vibrating a drill string includes an agitator housing, a rotor and an agitation mass. The drill string has a central axis. The rotor is coupled to the agitator housing and being rotatable about an agitator axis. The agitation mass is coupled to the rotor and is rotatable about the agitator axis. During rotation, a center of mass of the agitation mass is spaced apart from the agitator axis to cause deflection of the agitator axis relative to the central axis to produce vibration in the drill string.

Abstract: A drilling tool is disclosed. The two ends of the drilling tool are respectively connected with an upper drilling tool and a drill bit. The drilling tool includes an axial striking part, a torsional striking part, and an auxiliary part. Under the combined action of a spring and a high-pressure drilling fluid, the hammer of the axial striking part generates an axial striking force to strike the upper housing; and the pendulum of the torsional striking part generates a torsional striking force to strike the lower housing. The reversing switch and the center tube are plugged together to simultaneously reverse torsion and axial striking forces, respectively. The high-pressure drilling fluid pushes the hammer and the pendulum to generate axial and torsional striking forces, respectively, to effectively increase the ROP and reduce the stick-slip phenomenon. The drilling tool is stable and reliable in a complex and changeable downhole environment.

Abstract: The disclosure presents processes and methods for decomposing friction factors and generating a calibrated friction factor and adjusted input parameters. The calibrated friction factor and adjusted input parameters can be utilized by a borehole system as an input to adjust borehole operations to improve the operational efficiency. The friction factors can be decomposed by type, such as geometrical, geomechanical, mechanical, and fluid. The disclosure also presents processes and methods for identifying an outlier portion of a friction factor, as identified by a deviation threshold that can be used to identify adjustments to borehole operations in that portion of the borehole. A system is disclosed that is capable of implementing the processes and methods in a borehole operation system, such as a downhole system, a surface system, or a distant system, for example, a data center, cloud environment, lab, corporate office, or other location.

Abstract: A method of probabilistically estimating a velocity of a plunger of a beam pump may comprise continuously monitoring well acoustics using a plurality of passive acoustic sensors attached to external structures of the beam pump; digitizing outputs of the plurality of passive acoustic sensors and sending the digitized outputs to a computing device for storage and processing; and using the digitized outputs of the plurality of passive acoustic sensors, estimating a probability of the velocity of the plunger using a hidden Markov model (HMM) to represent a probability of a position and the probability of the velocity of the plunger, the HMM comprising a state space model and an observational model.

Abstract: The force modulation system for a drill bit includes a cutter, a blade cap, a cap retention device, and a first force member. The cutter or cutters fit in the blade cap, and the blade cap fits to the drill bit. The cap retention device exerts a cap retention force in a first direction. The first force member exerts a first force in a second direction. The cutting profile of the force modulation system is now variable in more than one direction so as to avoid excessive forces from more than one direction for each cutter on the blade cap. There can also be a second force member to exert a second force in the first direction for more variability of the cutting profile in the first direction and a third force member to exert a third force in an opposite second direction.

Abstract: The force modulation system for a drill bit includes a cutter, a holder, a holder retention device, and a first force member. The cutter fits in the holder, and the holder fits in the drill bit. The holder retention device exerts a holder retention force in a first direction. The first force member exerts a first force in a second direction. The second direction is angled offset to the first direction so as that the cutting profile of the force modulation system is now variable in the second direction, according to the first force. There can also be a second force member to exert a second force in the first direction for more variability of the cutting profile in the first direction. The second force member can be made integral with the first force member.

Abstract: Systems and methods for sealing a lost circulation zone associated with a subterranean well include a drill string with a circulating port and a lost circulation material. A lost circulation shape is a hollow body having an outer skin and an open interior chamber. The outer skin includes a plurality of perforations that extend through the outer skin, providing fluid communication between an exterior of the lost circulation shape and the open interior chamber. The plurality of perforations are sized to prohibit a passage of lost circulation material between the exterior of the lost circulation shape and the open interior chamber.

Abstract: A drilling liner is configured to be positioned in a lost circulation zone of a subterranean formation in which a wellbore is being drilled. The drilling liner is configured to flow wellbore drilling fluids from a surface of the wellbore to the subterranean formation while avoiding the lost circulation zone. The drill head assembly is attached to a downhole end of the drilling liner, and is configured to drill the subterranean formation to form cuttings, receive the wellbore drilling fluids, and flow the cuttings and the wellbore drilling fluids into the drilling liner while avoiding the lost circulation zone and towards the surface of the wellbore.

Abstract: A method includes acquiring data during rig operations where the rig operations include operations that utilize a bit to drill rock and where the data include different types of data; analyzing the data utilizing a probabilistic mixture model for modes, a detection engine for trends and a network model for an inference based at least in part on at least one of a mode and a trend; and outputting information as to the inference where the inference characterizes a relationship between the bit and the rock.

Abstract: A hybrid bit includes an earth-boring element and a percussion element. The earth-boring element and the percussion element are coaxially arranged, with the earth-boring element surrounding the percussion element. A reciprocating member of the percussion element may oscillate in a manner that enables a bottom end of the reciprocating member to repeatedly protrude from a bottom end of the earth-boring element and to be repeatedly withdrawn. A configuration of the earth-boring element may enable it to drill into and remove some materials from an earth formation, while the percussion element may enable the hybrid bit to drill into and remove difficult-to-drill materials, including abrasive materials and/or materials with high compressive forces, such as chert.

Abstract: A method of controlling the fracture location, orientation, and reduce the breakdown pressure in multistage fracturing, particularly of unconventional reservoirs. Acid etching can be used to initiate small channels (wormholes) around the horizontal well, followed by the hydraulic fracturing fluid to create the fractures. The fracture orientation can follow the same direction of the etched part of the well and in the same location of the wormholes. The breakdown pressure can be reduced by 5, 10, 15%, or more, e.g., from 2200 to 1800 psi after acid etching which can minimize the pumping requirements at the surface and break the formation with very high breakdown pressure.

Abstract: A diverter assembly may include a diverter body assembly. The diverter body assembly may also include a diverter body, the diverter body fluidly coupled to the annulus of a wellbore via a casing or riser, and the diverter body including one or more diverter outlet ports fluidly coupled to the annulus of the wellbore. The diverter body assembly may also include an upper packer assembly. The upper packer assembly may include a packer sleeve, the packer sleeve mechanically coupled to the diverter body. The packer sleeve may include one or more breach lock slots. The upper packer assembly may also include an upper packer body having one or more packer breach lock tabs engaged with the breach lock slots of the packer sleeve. The diverter assembly may also include a diverter support housing, the diverter support housing coupled to the diverter body assembly.

Abstract: Systems and methods of forming a seal employ a robust metal sealing unit for tubulars used in rotary drilling. Specifically, eutectic alloy is used to seal a tubular to a wellbore after drilling. A downhole heater melts the alloy, allowing the alloy to expand and drain before it cools and solidifies between the wellbore and tubular, forming a gas tight seal.

Abstract: An embodiment of the present disclosure provides a multi-path combined high-low voltage plasma drilling power source and drilling system. The multi-path combined high-low voltage plasma drilling power source comprises a high-voltage DC circuit, low-voltage DC circuits, high-voltage breakdown modules and an upper computer; wherein the high-voltage DC circuit is connected with the low-voltage DC circuits through cables; the low-voltage DC circuits and the high-voltage breakdown modules simultaneously supply power to plasma generators through cables; the upper computer monitors the low-voltage DC circuits in real time; and the same power source comprises a plurality of low-voltage DC circuits and high-voltage breakdown modules.

Abstract: Disclosed herein are various embodiments of methods and systems for drilling an oil or gas well safely and efficiently using underbalanced or near-balanced drilling techniques, wherein the primary means of pressure control is a Annular Pressure Control Diverter positioned below the BOP stack, with a return flow pattern where no drilling fluid returns up the (traditional) annulus between the drill pipe and the production casing and instead drilling fluid returns up the annulus between the production casing and intermediate casing. Drilling fluid returns flow through a wellhead, instead of a flow spool conventionally located below an upper RCD, and hence to the drilling choke. This drilling approach eliminates the need for hydraulic fracturing and preserves the natural fracture system of the producing formation while providing additional safety measures. It also prevents the accidental or deliberate discharge or flaring of methane during drilling and production.

Abstract: A drilling machine includes a mast, a rotary head movably coupled to the mast, a drill string component having a pair of opposed flat surfaces, and a securing structure including engagement surfaces shaped to engage the opposed flat surfaces and secure the drill string component from rotating. The drilling machine also includes a controller configured to track a rotational location of the flat surfaces of the drill string component during rotation of the drill string component. The controller is further configured to receive tracking information from a sensor associated with the rotary head and control the rotary head to align the opposed flat surfaces for engagement by the securing structure.

Abstract: A system for drilling a subterranean borehole. In an embodiment, the system includes a mast, and a pipe rotator coupled to the mast. The pipe rotator includes a stem that is configured to be coupled to an end of a drillstring and a motor that is configured to rotate the stem. In addition, the system includes a guide beam coupled to the mast. The guide beam includes a longitudinal axis and is configured to guide vertical motion of the pipe rotator. The guide beam includes a plurality of elongate sections configured to be generally aligned along the longitudinal axis. In addition, the guide beam includes a plurality of coupling assemblies configured to interconnect the plurality of elongate sections and align the plurality elongate sections along the longitudinal axis.

Abstract: A directional drilling system that includes a drill bit that drills a bore through rock. The drill bit includes an outer portion of a first material and an inner portion coupled to the outer portion. The inner portion includes a second material.

Abstract: A tubular delivery arm that travels vertically along a rail on the front of a drilling mast in generally parallel orientation to the travel of a top drive. The tubular delivery arm has a dolly vertically translatably connected to a mast of the drilling rig. An arm is rotatably and pivotally connected to the dolly at its upper end. A tubular clasp is pivotally connected to the arm at its lower end.

Abstract: A pullback device for attaching to a rotary drill bit that has a pair of wrench flats on its base without disassembling or removing the rotary drill bit from a drill string. The pullback device includes an anchoring portion including a collar configured to engage with the wrench flats of the rotary drill bit. The pullback device includes a plurality of arms, each of the plurality of arms having a first end including an attachment location configured to attach product to the pullback device for pullback of the product by the drill string, and each of the arms including a second end opposite the first end, the second end attached to the collar.

Abstract: Systems and methods for sealing a lost circulation zone associated with a subterranean well include a drill string with a circulating port and a lost circulation material. A lost circulation shape is a hollow body having an outer skin and an open interior chamber. The outer skin includes a plurality of perforations that extend through the outer skin, providing fluid communication between an exterior of the lost circulation shape and the open interior chamber. The plurality of perforations are sized to prohibit a passage of lost circulation material between the exterior of the lost circulation shape and the open interior chamber.

Abstract: A motor driven electromechanical actuator assembly includes a motor assembly having a motor shaft and a gear assembly. The gear assembly includes a plurality of gears with a belt drive that couples the motor assembly to the actuator output shaft. The actuator assembly also includes a position sensor system configured to determine a rotational characteristic of the drive shaft.

Abstract: The tool assembly includes a main body and a bypass assembly. The main body has an off-set through bore and a cavity to fit the bypass assembly. The cavity includes a cavity surface, a first fluid bypass port, a second fluid bypass port, and a pressure inlet port. There is also a flow restrictor in fluid connection with the pressure inlet port. The bypass assembly includes a bypass housing, a pressure chamber, a piston with a first piston position and a second piston position, and a spring assembly. A pressure differential created by fluid flow through the pressure chamber and flow restrictor actuates the piston between the first piston position and the second piston position. The proportional flow through the tool assembly and through the bypass ports can now be controlled to perform the downhole work, including drilling and hole cleaning.

Abstract: A system for injecting a portion of a drilling fluid waste into a well includes a receiving pit configured to receive a drilling fluid waste. A shaker is configured to receive the drilling fluid waste from the receiving pit and to separate solids from the drilling fluid waste to produce a separated drilling fluid waste. A mixing tank is configured to receive the separated drilling fluid waste from the shaker and to mix the separated drilling fluid waste. One or more tanks are configured to receive water. A pump is configured to cause the separated drilling fluid waste and the water to flow into a well.

Abstract: A cutter block includes a formation facing surface having a staged cutting profile and one or more stabilizer pads may be located between reaming portions. A shorter stabilizer pad or no stabilizer pad may be at the gauge of the cutter block. A spline on the cutter block and used by a downhole cutting apparatus to move the cutter block may intersect the formation facing surface. The spline may form an extension that increases a width of the formation facing surface. The extension may be located at a stabilizer pad to expand the stabilizer pad, such that the extension rotationally leads or trails cutting structure of the cutter block. When the cutter block is expanded, a stabilizer pad may be at a pilot diameter of a wellbore, while some cutting elements may be radially outside, and others radially within, the pilot diameter of the wellbore.

Abstract: A device (10) for facilitating the transport of an apparatus A along an upward or downward directed conduit or bore hole including a drill string (12) is described. The device (10) has a body (13) having an upper body portion (20) and a lower body portion (22) which are coupled together and movable axially relative to each other. A fluid flow path (58) internal of the body (13) selectively enables fluid to flow through the body (13). A first valve system 60 located at a first end of the internal fluid flow path (58) is operable by a pressure differential between a region external of the body (13) and the internal fluid flow path (58). A second valve system (51) is located at second end of the internal fluid flow path. The second valve system (51) is operable by relative movement between the upper body portion (20) and lower body portion (22).

Abstract: Anti-rotation pad assemblies are provided for restraining rotation of a non-rotating housing in geologic drilling system. The anti-rotation pad assemblies include extensible members, which extend from an internal cavity in the anti-rotation pad assemblies and are capable of engaging a wellbore wall. The extensible members may include rollers that are biased radially outwardly to engage the wellbore wall such that the anti-rotation pad assemblies may move axially within the wellbore while restraining the non-rotating housing in a particular rotational orientation. Flow ports are defined in the anti-rotation pad assemblies to encourage mud flow through the internal cavity, and thereby discourage the accumulation and solidification of drilling fluids around the extensible members. The extensible members thus remain free to move under the bias of a biasing mechanism within the internal cavity and can thus effectively maintain the rotational orientation of the non-rotating housing in the wellbore.

Abstract: A method for designing a core bit to control and reduce the cutting forces acting on a core of rock is disclosed. The method includes generating a model of a core bit including a plurality of cutting elements on a plurality of blades. The method may additionally include simulating a coring operation with the model of the core bit. The method may further include calculating at least one force vector generated by at least one of the plurality of cutting elements on the model of the core bit during the coring operation. The method may further include determining at least one force acting on a core in the model of the core bit based on the at least one force vector and generating a design of the core bit based on the at least one force acting on the core.

Abstract: A shaft enlargement arrangement for a boring system comprises a hollow column proximate a lower end of the boring system. A reamer section comprising a downwardly tapering first cutter head arrangement is rotatably fitted to the hollow column, with a first drive being provided to rotate the first cutter head arrangement relative to the hollow column so as to bore downwardly a hole having a diameter corresponding substantially to the diameter of the first cutter head arrangement. A boring head arrangement is fitted to an operatively lower end, the boring head arrangement terminating in a downwardly tapering second cutter head arrangement to bore a leading or pilot hole, having a diameter that is less than the diameter of the first cutter head arrangement, as the boring system proceeds to bore downwardly.

Abstract: A gooseneck (100) and a power swivel (10) including a gooseneck (100) are disclosed. In an embodiment, the gooseneck includes an inlet section (120) including an inlet (124) and a first fluid flow path (170) extending from the inlet. In addition, the gooseneck includes an outlet section (150) coupled to the inlet section. The outlet section includes an outlet (156). In addition, the outlet section (150) includes a second fluid flow path (160) extending axially from the outlet. The second fluid flow path is in fluid communication with the first fluid flow path. Further, the outlet section includes a radially outer surface (150c) that includes a first polygonal section having a plurality of planar surfaces (166) joined at a plurality of corners (168).

Abstract: A gap joint for use with a gap sub for electromagnetic telemetry. The gap joint has a replaceable uphole shoulder on the male gap joint component, which may be composed of a sacrificial material, to extend gap joint useful life where there is electrolysis of the component outside diameter. The gap joint also has a thicker outside diameter seal to reduce the risk of underlying O-ring extrusion and failure, again extending gap joint useful life. The thicker seal may also be able to withstand higher pressures before collapsing or experiencing punctures in unsupported areas. The replaceable shoulder and outside diameter seal can be used separately or together in a gap joint.

Abstract: A drilling system can include a downhole assembly with a liner hanger, a liner running tool, a lower wellbore liner, a cementing module, and a drilling tool. The drilling system can provide a single-trip procedure that enables a well operator to drill the wellbore while simultaneously running in a wellbore liner and subsequently cement the annulus around the lower wellbore liner. Once the cement is deposited, a liner hanger can be actuated and a liner running tool released to enable the remaining portions of the downhole assembly to be pulled out of hole while leaving the lower wellbore liner cemented in place.

Abstract: A rotatable bearing assembly transfers a weight of a drill string to a mud motor output shaft extending therethrough. The bearing assembly includes an outer bearing housing, an upper radial bearing assembly providing an upper radial bearing between the outer bearing housing and the output shaft, a balance piston that fluidly seals an upper end of the outer bearing housing and balances a pressure within the outer bearing housing, a lower radial bearing/seal assembly configured to both fluidly seal a lower end of the outer bearing housing and provide a lower radial bearing between the outer bearing housing and the output shaft, and a thrust bearing assembly received within the sealed interior of the outer bearing housing such that the bearing assembly initially operates in a sealed, lubricated mode and then a mud lube mode in the event of one or more seal failures. Other embodiments are also disclosed.

Abstract: A dresser includes: a mount component; and a cutting edge component inserted in the mount component at a base end portion side, wherein the portion of the cutting edge component inserted in the mount component has one or more portions in each of which an area of a cross section is increased from the front end portion side toward the base end portion side in the insertion direction, and a ratio L1/M1 of a length L1 and a maximum value M1 is more than or equal to 2.1, where L1 represents a length of the portion of the cutting edge component inserted in the mount component and M1 represents a maximum value of a diameter of a circle having an area equal to the area of the cross section of the portion of the cutting edge component inserted in the mount component.

Abstract: An autonomous drilling pressure control system for use with a drilling rig includes a pressure control device for controlling pressure within an annulus of an associated well, an electronic pressure sensor for monitoring pressure within the annulus, and an electronic position indicator for indicating a position of the pressure control device. A control subsystem independent of the drilling rig and responsive to the pressure sensor is provided for manipulating the pressure control device to control the pressure within the annulus of the associated well. At least one dedicated power source independent of the drilling rig supplies power to the pressure sensor and position indicator.

Abstract: It is described how to provide a drilling fluid for earth drilling, wherein the drilling fluid comprises a liquid and at least one mineral. A recycling device preconditions supplied drilling fluid. At least one drilling fluid analyzer is provided for determining the state of drilling fluid that comes out of the borehole. There is also a mixing device for mixing drilling fluid reconditioned by the recycling device with liquid and/or mineral, wherein the mixing device is coupled to the drilling fluid analyzer in order to perform mixing according to the state of the drilling fluid.

Abstract: An electric driven hydraulic fracking system is disclosed. A pump configuration includes the single VFD, the single shaft electric motor, and the single hydraulic pump mounted on the single pump trailer. A controller associated with the single VFD and is mounted on the single pump trailer. The controller monitors operation parameters associated with an operation of the electric driven hydraulic fracking system as each component of the electric driven hydraulic fracking system operates to determine whether the operation parameters deviate beyond a corresponding operation parameter threshold. Each of the operation parameters provides an indicator as to an operation status of a corresponding component of the electric driven hydraulic fracking system. The controller initiates corrected actions when each operation parameter deviates beyond the corresponding operation threshold.

Abstract: The present invention relates to a device and a method for the implementation of a flexible tubular structure made of reformable composite material, designed for passing from a first folded configuration to a second longitudinally developed operating configuration using a tapered profile slidingly engageable inside the tubular structure.

Abstract: A downhole cutting apparatus includes a cutter block. The cutter block includes a formation facing surface with cutting elements coupled thereto. The cutting elements are arranged in rows that may extend at an angle across a width of the formation facing surface. Mud flutes may optionally be located between rows of cutting elements. A gauge portion of the formation facing surface may be adjacent a leading edge having reinforcement members coupled thereto.

Abstract: A drill bit analysis and optimization system for use in a wellbore is provided. The system includes a drill bit including a cutter, a sensor that collects a data signal on a surface of the drill bit proximate to the cutter, and a signal processor unit that receives the data signal from the sensor and receives the expected drilling properties from the data reservoir. The processor analyzes the data signal to detect a resistivity profile from the sensor through a formation and optimizes a drilling parameter by comparing actual drilling properties with expected drilling properties.

Abstract: A method includes receiving a plurality of signals from a plurality of sensors into a programmable logic controller, the plurality of sensors provided on at least one component of a rotating control device assembly of a drilling system, providing measurement data from the plurality of signals using the programmable logic controller, and processing the measurement data using a modeling software to determine at least one condition of the rotating control device assembly.

Abstract: A fingered member for a downhole tool that includes a circular body made of a composite material, and also a plurality of fingers integral to and extending from the circular body. At least one of the plurality of fingers has an insert carriage disposed therein. The insert carriage is made of a reactive metallic material.

Abstract: An apparatus including a rotating segment having a first radial surface, a non-rotating segment having a second radial surface, a housing disposed around the first and second radial surfaces, and one or more rolling elements disposed between and in contact with the first and second radial surfaces for transferring the non-rotating segment in an axial direction upon rotation of the rotating segment. The non-rotating element may be a second rotating element that rotates at a different rotational rate than the rotating element. Each rolling element moves 360 degrees along a circular path relative to the first radial surface and the second radial surface. The first or second radial surface has a tapered section.

Abstract: A rotatable cutter may comprise a rotatable element, a stationary element, and a releasable interface. The releasable interface may be configured to substantially inhibit rotation of the rotatable element when the rotatable element and the stationary element are at least in partial contact. An earth-boring tool may include one or more rotatable elements.

Abstract: A method of detecting the presence of a downhole fluid at a particular location in a wellbore including pumping an activating fluid into a wellbore; contacting a flow controlling device in a pipe string casing with the activating fluid, the flow controlling device comprising at least one swellable element; activating the at least one swellable element in the flow controlling device; blocking fluids or controlling the flow of fluids entering or leaving the casing with the activated flow controlling device; allowing the pressure to change; and detecting the pressure change. An apparatus includes a pipe string in a wellbore and a flow controlling device in the pipe string casing, wherein the flow controlling device includes at least one swellable element, wherein upon activation, the at least one swellable element swells and fully or partially seals off the flow area of the flow controlling device.