In various embodiments a controller for controlling the operation of a switched mode power supply is provided, the controller comprising: a first signal source configured to provide a first set of signals including a set signal and a clear signal, wherein the first set of signals may correspond to a first mode of operation of the switched mode power supply; a second signal source configured to provide a second set of signals including a set signal and a clear signal, wherein the second set of signals may correspond to a second mode of operation of the switched mode power supply; a selecting circuit coupled to the first signal source and to the second signal source, the selecting circuit being configured to select either the first set of signals or the second set of signals; a switching signal generating circuit coupled to the selecting circuit and configured to provide a switching signal to the switched mode power supply based on the set of signals received from the selecting circuit.

A synchronous DC-DC converter having a soft-stop function includes an output stage for supplying an output voltage, wherein the output stage includes a high-side transistor for charging the output voltage and a low-side transistor for discharging the output voltage; an output control circuit, coupled to the output stage, for controlling the high-side transistor and the low-side transistor of the output stage; at least one protection device, for controlling the high-side transistor to be turned off when a specific situation occurs, in order to stop supplying the output voltage; and a soft-stop control circuit, coupled to the output control circuit, for controlling the low-side transistor of the output stage to be turned on when the protection device controls the high-side transistor to be turned off or the synchronous DC-DC converter is disabled, in order to discharge the output voltage.

A step-down regulator comprising a pseudo constant on time control circuit is disclosed, comprising an on-time generator configured to receive a switching signal provided by the step-down regulator and a control signal provided by the pseudo constant on time control circuit, and generates an on-time signal; a feedback control circuit configured to receive a feedback signal representative of the output voltage of the step-down regulator and generate an output signal; and a logic control circuit coupled to the on-time generator and the feedback control circuit to receive the on-time signal and the output signal and generating the control signal, and a power stage configured to receive an input voltage and the control signal and generate the switching signal.

Systems and methods that provide control circuits having multiple sub-control inputs that control operation of a power electronics device (e.g., a power converter). Each of the multiple sub-control inputs are output from a separate sub-control circuit that includes a feedback circuit having an input tied to a common control node. The common control node is coupled to an input of a controller (e.g., a PWM controller). Outputs of each of the sub-control circuits are coupled to the common control node by a respective switch (e.g., diode, transistor, etc.) so that each of the sub-control circuits may be selectively coupled to the common control node to provide a control signal to a controller. Since components of each of the feedback compensations circuits are biased at a regulation voltage instead of a higher power supply voltage, the control circuit may switch between control modes with minimal delay.

An electronic apparatus includes a switching element which has a control terminal and is driven by controlling voltage of the control terminal, a driving power supply circuit which supplies voltage required for driving the switching element, an on-driving circuit which is connected to the driving power supply circuit and the control terminal of the switching element and is supplied with voltage from the driving power supply circuit, and which applies a constant current to the control terminal of the switching element to charge the control terminal, thereby turning on the switching element, and at least one diode which is connected between the on-driving circuit and the control terminal of the switching element. The on-driving circuit applies a constant current to the control terminal of the switching element through the diode.

Polyphase converter, comprising a plurality of electrical phases (11 to 16), which can each be driven by switching means (21 to 26), wherein at least one coupling means (31 to 39) is provided, which magnetically couples at least one first phase (11) to at least one further phase (12, 14, 16), wherein at least two phases (11, 12) to be coupled are surrounded at least partially by the coupling means (31), wherein at least one insulating body (72) is provided, which on the upper or lower side thereof accommodates the phases (11 to 16) to be coupled and on which at least one fastening means (74, 76, 90) is provided, which interacts with at least one of the phases (11 to 16) for fastening purposes.

An integrated power quality control system includes a transformer with a primary winding, a secondary winding and a compensation winding wound on a magnetic core. A power electronic converter in the system provides a reference voltage to the compensation winding for injecting a series voltage in the secondary winding of the transformer. A controller is utilized to generate a reference control voltage for the power electronic converter based on a power quality control requirement.

A system that manages a supplemental energy source connected to a power grid uses a two stage control strategy to manage power transfers in and out of the power grid as well as in and out of an energy storage system, such as a battery bank. One stage uses a non-linear transfer function to control an output frequency of a DC-to-AC inverter to limit undesired effects of power transients that occur on the grid. A second stage uses control strategy for transferring energy between the energy storage system and an internal DC link based on a relationship between a voltage on a DC link connecting the first and second stages and a DC link reference voltage, the voltage on the DC link, and a voltage at the energy storage system. The control strategy includes rapid charging, over-charging protection, and grid transient stabilization.

There is provided a DC-DC converter which converts an input voltage into an output voltage for supply to a load, in which an input terminal receives the input voltage, an output terminal outputs the output voltage, power stages each includes: a high side switch, a low side switch and an inductor, the control unit executes a first mode and a second mode wherein the first mode controls the high side switch and the low side switch in each of the power stages so that a ratio of an output current in each of the power stages to a load current flowing through the load becomes a set value and the second mode controls the high side switch and the low side switch in each of the power stages so that duty ratios of the high side switch and the low side switch are equalized among the power stages.

A power control circuit for a power supply system including a control unit, a driving circuit and a power supply unit is disclosed. The power control circuit includes a current detection unit, a voltage detection unit and a power detection unit. The current detection unit is used for detecting a current signal. The voltage detection unit is used for detecting a voltage signal. The power detection unit is connected with the current detection unit, the voltage detection unit and the control unit for acquiring a power signal according to the current signal and voltage signal. By comparing an adjustable power reference signal with the power signal, the control unit issues a control signal to the driving circuit. In response to the control signal, the power supply unit is driven by the driving circuit to output an adjusted power to the load according to the adjustable power reference signal.

A mode controller shifts, along with increase in an electric power in first and second of chopper circuits and, operation modes of the first and the second of the chopper circuits from a first mode to a third mode via a second mode. An operation controller causes, in the first mode, the first of chopper circuit to perform an chopping operation, and the second of chopper circuit to suspend the chopping operation, in the second mode, causes the first and the second of chopper circuits to alternatively perform the chopping operations, and in the third mode causes both of the first and the second of chopper circuits to perform the chopping operations.

A radio controlled UAV is disclosed. The UAV includes a parachute, with a cylindrical power and control module suspended vertically below the parachute. In one embodiment, a propulsion source is mounted on top of the power and control module with control lines connected to the module below the propulsion source, and in another embodiment the power and control module is suspended from a point above a propulsion source. The UAV is controlled by radio controls from a hand held controller, with actuators retracting and letting out control lines attached to the parachute in order to control direction of the parachute. The UAV may be launched from a tube using a pressurized tank with a nozzle expelling gas from the tank, the tank and nozzle towing a canister from which the UAV is deployed.

In a method for reducing the impact of a force upon a person seated in a safety seat of a motor vehicle at least a seat unit of the safety seat is restrained at least in part by at least one support strap. The support strap is formed with an extension piece configured to lengthen when exposed to a load as a result of an accident or explosion. A winding unit holds the support strap to shorten an effective length of the support strap and to build up a force to maintain the support strap under tension after the support strap underwent a lengthening in an area of the extension piece as a result of a load caused by a force resulting from an accident or explosion so as to reestablish an effective length of the support strap for lengthening during a subsequent force impact.

An exoatmospheric vehicle uses a control system that includes a thrust system to provide thrust to control flight of the vehicle. A regenerative heat system is used to preheat portions of the thrust system, prior to their use in control of the vehicle. The heat for preheating may be generated by consumption of a fuel of the vehicle, such as a monopropellant fuel. The fuel may be used to power a pump (among other possibilities), to pressurize the fuel for use by thrusters of the thrust system. The preheated portions of the thrust system may include one or more catalytic beds of the thrust system, which may be preheated using exhaust gasses from the pump. The preheating may reduce the response time of the thrusters that have their catalytic beds preheated. Other thrusters of the thrust system may not be preheated at all before operation.

A method and apparatus for lighting a flight deck on an aircraft. A status of the aircraft is identified by a processor unit. The processor unit controls the lighting on the flight deck in response to the status of the aircraft to indicate the status of the aircraft.

Systems and methods for performing airport surface collision-avoidance. A wingtip-mounted camera allows the pilot to positively ascertain that the wingtip will clear objects located in the video. An exemplary system implemented on an aircraft includes a wingtip module having a camera that generates a video stream and a communication device that transmits the generated video stream. A processor receives the video stream and generates a reticule for the video stream. A display device simultaneously presents the video stream and the reticule. The reticule includes a horizon line and is based on a focal length of a lens of the camera and height of the camera above ground. The reticule includes curved and/or straight distance lines and curved or straight travel lines. The travel line(s) correspond to at least one aircraft component or a zone of importance and are based on location of the camera and trajectory of the aircraft.

The invention relates to a de-icing device for an element of a nacelle of a turbojet engine, including at least one heating resistant mat connected to at least one electrical power source (3) and thus defining an assembly (1) of resistant mats, characterized in that the assembly of resistant mats includes one or more subassemblies of resistant mats, each subassembly in turn including one or more resistant mats of the assembly, and each subassembly of resistive mats having a different ohmic value.

A method of controlling a group (2) of engines developing a necessary power (Wnec) for driving a rotor (3), said group (2) of engines having at least one electrical member (4), electrical energy storage means (5), and a first number n of engines (6) that is greater than or equal to two. A processor unit (10) executes instructions for evaluating a main condition as to whether the group of engines can develop the necessary power while resting one engine, and if so for resting one engine and accelerating a second number engines not at rest, and for causing the electrical member to operate in motor mode, if necessary, the electrical member operating temporarily in electricity generator mode when the storage means are discharged.

A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for maintaining the rigidity of the rotor and eliminating play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Methods are disclosed for modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. A rotor facilitating thermal management by oil and air flow is also disclosed. Surfaces interfacing between the swashplate and the mast and between control rods and the swashplate or pitch horn may bear a solid lubricant layer.

An unmanned, towable aerovehicle is described and includes a container to hold cargo, an autogyro assembly connected to the container and to provide flight characteristics, and a controller to control operation the autogyro assembly for unmanned flight. The container includes a connection to connect to a powered aircraft to provide forward motive force to power the autogyro assembly. In an example, the autogyro assembly includes a mast extending from the container, a rotatable hub on an end of the mast, and a plurality of blades connected to the hub for rotation to provide lift to the vehicle. In an example, an electrical motor rotates the blades prior to lift off to assist in take off. The electrical motor does not have enough power to sustain flight of the vehicle.

Individually operable ailerons pivotable to extend a forward end below a bottom wing surface and a rearward end above a top wing surface. The extended aileron forward end increases drag and subsumes the rudder function in the turn, while the aileron rear end produces drag and airflow redirection to reduce lift on the wing. The advantage of the safety ailerons is that habitual or instinctive pilot inputs to the yoke will recover from a dropped-wing stall at low speed and altitude, while conventional ailerons require counter-intuitive pilot actions to avoid crashing in such conditions.

According to one embodiment, a windshield attachment device for coupling a windshield to a body includes a fastener portion, a bolt, and an elastomeric load isolator. The fastener portion has an opening therethrough. The bolt is configured to extend through the opening of the fastener portion and couple the fastener portion to the body. The elastomeric load isolator surrounds at least a portion of the fastener portion and separating the fastener portion from the windshield.

A method and apparatus comprising a refueling controller. The refueling controller is configured to receive data about a current rate of movement of a refueling boom while the refueling boom is in contact with a receiver aircraft during flight. The refueling controller is further configured to disconnect the refueling boom from the receiver aircraft based on the current rate of movement of the refueling boom and a current position of the refueling boom.

Certain embodiments described herein are directed to devices configured to retain, at least for some period, and provide pre-launch support kites such as stunt kites. In certain instances, the device positions stunt kites of various sizes and design, including, for example, delta wing kits, diamond kits and foil kits, in a reclined position to provide pre-launch stability and wind flow/spill-over across the face of the kite to help prevent unintentional or premature launch. If desired, optional control line upright supports can be present that permit minimum control line pull-back thereby reducing the recline of the kite to bring the face of the kite into the wind and thereby launch the kite. The control line upright supports may also prevent the kite from falling completely face down on the surface, thereby requiring a reset of the kite on the device.

A system has a plurality of spacecraft in orbit around the earth for collecting energy from the Sun in space, using stimulated emission to configure that energy as well defined states of the optical field and delivering that energy efficiently throughout the region of space surrounding Earth.

Methods and apparatus are presented for spacecraft operation using non-Eigen axis attitude transitions via control momentum gyroscopes (CMGs) to avoid or mitigate singularities by providing a time-varying attitude command vector including a plurality of time-varying attitude command signals or values representing a plurality of spacecraft states and control trajectories as a guidance command input to an attitude controller of the spacecraft without modifying the spacecraft feedback control law.

A method for simulating the movement behavior of a fluid in a closed moving container is provided. The simulation is based on the determination of the potential movement path of the center of gravity of the volume of the fluid as an elliptical trajectory situated in a disturbance plane having certain semi-axes.

A system and method for mitigating an aircraft incident is provided. The invention includes an aircraft panic component coupled to a terminal component. The aircraft panic component facilitates identification of a panic situation and communicates information associated with the panic situation to the terminal component. The aircraft panic component is further operative to at least partially disable a navigation system and/or operational system of an aircraft. The aircraft can then be sent to a safe zone, navigated remotely and/or a course of action for the aircraft can be determined. A safe zone component is adapted to facilitate identification of a course of action for the aircraft based at least in part upon aircraft positional information, aircraft condition information and/or aircraft resource(s). Further, aircraft navigational information and/or aircraft operational information can be sent via an aircraft communication component to a remote system having a remote communication component and a remote analyzing component facilitating transfer of information related to navigational and/or operational system(s) of the aircraft.

An aerodynamic control surface assembly comprising: an aerodynamic control surface (4); an actuator (10) for controlling deployment of the control surface; and a locking mechanism (30) moveable from a locked to an unlocked position. When the locking mechanism is set to the locked position, the actuator is operatively coupled to the control surface and the control surface can move in dependently of the actuator when the locking mechanism is set to the unlocked position. Such an assembly may be used in an aircraft to prevent clashing between a deployed flap (16) and a drooped spoiler (4) in the event of an actuator control systems failure.

A variable length light shield is disclosed for an electro-optical sensor within a nose cone. The light shield includes a base, a telescopic shade supported by the base, and a ring rotatably supported about the base. The light shield also includes a guide tube disposed proximate the ring with an end extending away from the ring about a side of the telescopic shade. The light shield further includes an extension spring supported by the guide tube with an end coupled to the telescopic shade. Additionally, the light shield includes a cable extending through the guide tube and the extension spring, with one end of the cable coupled to the ring and another end of the cable coupled to the telescopic shade. The extension spring is configured to exert a force on the telescopic shade to extend the telescopic shade. Rotation of the ring causes retraction of the telescopic shade.

The invention is a projectile, device and system having a roll control device which may be fixed or deployable, for providing torque counter to the spin of the projectile and providing drag on the projectile. The roll control device includes a guidance collar rotatably attached to the projectile located near a front end of the projectile wherein the guidance collar includes one or more guidance collar aero-surfaces shaped to provide torque counter to the spin on the projectile. The guidance collar aero-surfaces may be controlled by a brake and guidance electronics on the projectile. The invention also includes a body collar fixedly attached to the projectile aft of the guidance collar, wherein the body collar includes one or more body collar aero-surfaces and fixed or deployable drag devices. Another embodiment use only a guidance collar aero-surfaces to orient a fixed drag device relative to an Earth inertial reference frame to create asymmetrical drag on the projectile and thereby altering its trajectory.

A projectile control system includes a plurality of fins, a drive mechanism coupled to each of the plurality of fins to enable the plurality of fins to be independently retracted or deployed, and a control mechanism in communication with the drive mechanisms to independently control the deployment or retraction of the plurality of fins. A projectile having the projectile control system and a method of operating a projectile are also described herein.

An actuation system and method includes a tubular defining a passage, and an assembly disposed with the tubular. The assembly includes a restriction operatively arranged to receive a restrictor for enabling actuation of the assembly. The restriction includes a degradable material with a protective layer thereon, the degradable material degrading upon exposure to a fluid in the passage and the protective layer isolating the degradable material from the fluid.

The well pump flow sleeve assembly provides a method of quickly fitting a flow sleeve to a well pump. The sleeve is made by cutting a pipe normal to the pipe centerline of the pipe surfaces, to a length appropriate for the well pump length. A pump centering bottom cap is inserted into the pipe lower opening and the well pump assembly is then inserted into the pipe upper opening and mates with the bottom cap to align the pump in the sleeve. The pump is now completely within the sleeve with the pump discharge and electrical connection extending through the pipe upper opening. Two flow sleeve cap halves are then fitted around the pump discharge and electrical connection/safety rope to form an upper cap which is inserted into the pipe upper opening. The submersible pump is then ready for service.

Use of two different methods, either each by itself or in combination, to enhance the stiffness, strength, maximum possible use temperature, and environmental resistance of thermoset polymer particles is disclosed. One method is the application of post-polymerization process steps (and especially heat treatment) to advance the curing reaction and to thus obtain a more densely crosslinked polymer network. The other method is the incorporation of nanofillers, resulting in a heterogeneous “nanocomposite” morphology. Nanofiller incorporation and post-polymerization heat treatment can also be combined to obtain the benefits of both methods simultaneously. The present invention relates to the development of thermoset nanocomposite particles. Optional further improvement of the heat resistance and environmental resistance of said particles via post-polymerization heat treatment; processes for the manufacture of said particles; and use of said particles in the construction, drilling, completion and/or fracture stimulation of oil and natural gas wells are described.

Fluid treatment systems and compositions are provided including (a) at least one material including (1) at least one carboxylic acid functional group and (2) at least one sulfur-containing group selected from the group consisting of sulfonyl functional groups, sulfonate functional groups and mixtures thereof; and (b) at least one friction reducing agent selected from the group consisting of guar gums, polyacrylamides, hydratable cellulosic materials, viscoelastic surfactants, and mixtures thereof. The fluid treatment systems and compositions can be used to treat aqueous systems, for example as fracturing fluids for use in fracturing subterranean formations. Methods for inhibiting formation and/or precipitation of metal oxides in an aqueous composition using the fluid treatment systems or compositions also are provided.

Fluid treatment systems and compositions are provided including (a) at least one material including (1) at least one carboxylic acid functional group and (2) at least one sulfur-containing group selected from the group consisting of sulfonyl functional groups, sulfonate functional groups and mixtures thereof; and (b) at least one scale control agent. The fluid treatment systems and compositions can be used to treat aqueous systems, for example as fracturing fluids for treating aqueous compositions found in subterranean formations. Methods for inhibiting formation and/or precipitation of calcium salts in an aqueous composition using the fluid treatment systems or compositions also are provided.

Methods are provided for identifying the location and height of induced subterranean formation fractures and the presence of any associated frac-pack or gravel pack material in the vicinity of the borehole using pulsed neutron capture (PNC) logging tools. The proppant/sand used in the fracturing and packing processes is tagged with a thermal neutron absorbing material. When proppant is present, increases in detected PNC formation and/or borehole component cross-sections, combined with decreases in measured count rates, are used to determine the location of the formation fractures and the presence and percent fill of pack material in the borehole region. Changes in measured formation cross-sections relative to changes in other PNC parameters provide a relative indication of the proppant in fractures compared to that in the borehole region.

Methods of treating a wellbore in a subterranean formation including providing an oil-external treatment fluid, wherein the oil-external treatment fluid is a 3D-network comprising a chemical interaction between a hydrocarbon fluid, an aqueous fluid, and a surface modification agent; providing proppant particulates; suspending the proppant particulates in the oil-external treatment fluid; and introducing the oil-external treatment fluid comprising the proppant particulates into the wellbore in the subterranean formation.

A method may include determining a first particle size distribution for particulate additives in a first wellbore fluid circulated through a wellbore through an earthen formation, and determining a second particle size distribution for drilled cuttings resulting from drilling of the wellbore. The first and second particle size distributions may then be compared to determine a third particle size distribution for the combined particulate additives and the drilled cuttings. A lost circulation material having a fourth particle size distribution may then be selected based on the third particle size distribution and the selected lost circulation material may be pumped into the wellbore.

A pourable aqueous cement composition is disclosed. The cement composition comprises a hydraulic cement, water and a selectively removable material comprising a plurality of selectively corrodible metal powder particles dispersed within the cement or a nanomatrix powder compact, or a combination thereof. An article, including a downhole article, and more particularly a reconfigurable downhole article is disclosed. The article includes a hydraulic cement, wherein the hydraulic cement has at least partially set into a permanent form. The article also includes a selectively removable material dispersed within the cement, the selectively removable material comprising a plurality of selectively corrodible metal powder particles dispersed within the cement or a nanomatrix powder compact, or a combination thereof, wherein the selectively removable material is configured for removal in response to a predetermined wellbore condition.

In an embodiment, the cement compositions comprise: (i) hydraulic cement, wherein the hydraulic cement has a ratio of CaO to SiO2 in the range of 2.0 to 4.0; and (ii) a water-soluble metaphosphate in a concentration of at least 2.5% bwoc. In another embodiment, the cement compositions comprise: (i) hydraulic cement, wherein the hydraulic cement has a ratio of CaO to SiO2 of less than 2.0; and (ii) a water-soluble metaphosphate; wherein any alkali nitrate is in a concentration of less than 2% bwoc; and wherein any alkali hydroxide, alkali carbonate, or alkali citrate is in a concentration of less than 0.2% bwoc. Methods of cementing in a well comprising forming either of such cement compositions and introducing it into the well are provided.

An oxygen scavenger for completion brines effective and stable in high temperature subterranean formations. In one embodiment, the scavenger contains erythorbate and alkylhydroxlyamine.

Systems and methods for managing umbilical lines and one or more jumpers are provided. An example of a system includes a deployment platform carrying a winch and spool assembly, a tether management assembly, and an integrated electrical and/or hydraulic umbilical line extending between a spool on the winch and spool assembly and the tether management assembly. The winch and spool assembly is configured to deploy and to support the umbilical line. The tether management assembly includes a winch and spool assembly for deploying a flying lead and/or annulus jumper adapted to connect to an emergency disconnect package of a well control package for a well. A set of buoyant modules are connected to or integral with a portion of the umbilical line to be used to form an artificial heave compensation loop.

A tool for actuating a blow out preventer includes one or more connections for receiving hydraulic power from a remotely operated vehicle (“ROV”), a first pump for increasing pressure of an operating fluid for the blowout preventer (“BOP”), a second pump for increasing flow rate of the operating fluid, and a conductor for transporting the operating fluid to the BOP. The tool rapidly increases the pressure and flow rate of the fluid flowing to the BOP, and the BOP may be rapidly closed.

A system for diverting fluids from a wellhead in a subsea environment has a capping stack with a connector suitable for connection or interconnection to the wellhead, a flow base fixedly positioned in the subsea environment, and a conduit connected to the outlet of a diverter line of the capping stack and connected to the inlet of an interior passageway of the flow base. The conduit is suitable for passing fluids from the capping stack toward the flow base. The flow base is a modified horizontal Christmas tree. The interior passageway within the horizontal Christmas tree has a plug therein located a level below the level of the inlet to the flow base. The flow base can be attached to a wellhead or to an anchor pile in the subsea environment.

An adapter assembly having a sealing element, a drive bushing, and an adapter flange disposed between the sealing element and the drive bushing. Also, a method of assembling a rotational control device that includes coupling mechanically an adapter flange to a sealing element, coupling mechanically the adapter flange to a drive bushing, and installing the adapter flange, sealing element, and drive bushing in the rotational control device.

The present invention relates to an inflow control device for controlling the flow of fluid into a well tubular structure arranged in a borehole, comprising a tubular part for mounting as part of the well tubular structure, an aperture provided in a wall of the tubular part, and a hollow valve member rotatably received inside the tubular part, the hollow valve member comprising an orifice in a wall thereof, and an outer surface of the hollow valve member being spherical and the orifice being adapted to fluidly communicate with the aperture when the inflow control device is in an open position, whereby the aperture is in fluid communication with an inside of the tubular part, wherein the hollow valve member comprises a spherical first valve part and a spherical second valve part adapted to be assembled inside the tubular part. The present invention furthermore relates to a method of assembling an inflow control device according to the invention and to a completion system comprising an inflow control device according to the invention.

A flow control device comprises a fluid pathway configured to provide fluid communication between an exterior of a wellbore tubular and an interior of the wellbore tubular, a flow restriction disposed in the fluid pathway, wherein the flow restriction is disposed in a radial alignment with respect to the wellbore tubular, and a flow blockage disposed in the fluid pathway, wherein the flow blockage substantially prevents a fluid flow through the fluid pathway.

A method for determining position of a wellbore in the Earth's subsurface includes actuating a plurality of seismic energy sources each disposed at a known geodetic position. Seismic energy from the sources is detected at a selected location along the wellbore. The geodetic position at the selected location is determined from the detected seismic energy. A corresponding method includes actuating a seismic energy source at a selected position within the wellbore. The seismic energy is detected at a plurality of known geodetic positions. The geodetic position of the source is determined from the detected seismic energy.