Abstract: A remote field eddy current, RFEC, system for detecting an azimuth location of a defect in a pipe includes a holder extending along a longitudinal axis X and shaped to flow through the pipe, a magnetic field generator located within the holder and configured to generate a first magnetic field B0, a 3-axis fluxgate magnetometer located within the holder, at a given distance away from the transmitter, along the longitudinal axis X, wherein the fluxgate magnetometer is configured to measure a second magnetic field B, which is a result of the first magnetic field B0 interacting with the defect in the pipe, and a controller located within the holder and configured to receive a value of the second magnetic field B and to determine an azimuth of the defect in the pipe by interpreting radial components of the measured field, and an extent of the defect based on the second magnetic field B.

Abstract: A wellbore assembly includes a wellbore string disposed within a wellbore and a cement retainer coupled to a downhole end of the wellbore string. The cement retainer includes a housing, a packer, a valve, and a sleeve. The housing includes one or more fluid ports extending from an interior surface of the housing to the annulus. The housing defines a first fluid pathway extending from within the wellbore string to within the housing. The sleeve is movable between a first position, in which the sleeve blocks the one or more fluid ports, and a second position in which the sleeve exposes the one or more fluid ports to open a second fluid pathway extending from the annulus, through the one or more fluid ports, to the first fluid pathway. Opening the second fluid pathway allows mixing of a first fluid with a second fluid in the cement retainer.

Abstract: A multifunctional drilling enhancement tool includes a shaft having a bore extending along a longitudinal direction (X); a main cutting device rotatably and slidably attached to the shaft; a first housing fixedly attached to a first end of the shaft; a second housing fixedly attached to a second end of the shaft; first and second proximal engagement elements attached to opposite ends of the main cutting device; and first and second distal engagement elements attached to corresponding ends of the first and second housings, so that the first distal engagement element is directly facing the first proximal engagement element, and the second distal engagement element is directly facing the second proximal engagement element.

Abstract: A method may include providing a stator. The method may also include equipping the stator with quadruple three-phase winding sets with concentrated fully-pitched winding. The quadruple three-phase winding sets may be connected in such a way that emulates a six-phase stator. Further, the quadruple three-phase winding sets may have the same conductor cross-sectional area. In addition, the quadruple three-phase winding sets may include a plurality of winding groups.

Abstract: The multifunction wellbore conditioning tool (100, 200, 300) is installed in the bottom hole assembly of a drill string and performs the functions of a cutting tool, keyseat wiper, roller reamer, keyseat wiper, and stabilizer during drilling operations, precluding the need for multiple different tools in the drill string. The tool (100, 200, 300) has a working sleeve (114, 214, 314) captured concentrically on the driveshaft (102, 202, 302) between opposed spring sets (134, 136; 234, 236; 334, 336). The sleeve (114, 214, 314) remains rotationally stationary about the rotating driveshaft (102, 202, 302) when in its central or neutral position on the driveshaft (102, 202, 302). When the sleeve (114, 214, 314) shifts axially on the driveshaft (102, 202, 302) it engages a clutch mechanism that allows it to rotate with the driveshaft (102, 202, 302) so that the rotating working sleeve (114, 214, 314) conditions the borehole.

Abstract: Systems, methods, apparatuses, and computer program products for drone based network optimization are provided. An inductive-capacitive circuit may include a first branch including a first energy storage element. The inductive-capacitive circuit may also include a second branch including a second energy storage element and a third energy storage element. In addition, the inductive-capacitive circuit may include a third branch including a fourth energy storage element and a fifth energy storage element, and a power source supplying a current through the first branch, the second branch, and the third branch. Further, the first branch, the second branch, and the third branch may be connected to at least one common node of the inductive-capacitive circuit.

Abstract: A method may include providing a stator. The method may also include equipping the stator with quadruple three-phase winding sets with concentrated fully-pitched winding. The quadruple three-phase winding sets may be connected in such a way that emulates a six-phase stator. Further, the quadruple three-phase winding sets may have the same conductor cross-sectional area. In addition, the quadruple three-phase winding sets may include a plurality of winding groups.

Abstract: Systems, methods, apparatuses, and computer program products for drone based network optimization are provided. An inductive-capacitive circuit may include a first branch including a first energy storage element. The inductive-capacitive circuit may also include a second branch including a second energy storage element and a third energy storage element. In addition, the inductive-capacitive circuit may include a third branch including a fourth energy storage element and a fifth energy storage element, and a power source supplying a current through the first branch, the second branch, and the third branch. Further, the first branch, the second branch, and the third branch may be connected to at least one common node of the inductive-capacitive circuit.

Abstract: An electrical converter is provided, comprising a first half-bridge sub-module, a switch, and a first capacitor. The half-bridge sub-module is connected to the first capacitor, and the switch is connected to a terminal of the first half-bridge sub-module. The switch includes a plurality of insulated-gate bipolar transistors. The insulated-gate bipolar transistors are serially connected with each other.

Abstract: An electrical converter, comprising a plurality of first modules and a plurality of second modules. At least one of the plurality of first modules includes a half-bridge module coupled with a direct current (DC)-link capacitor. A diode connected across the DC-link capacitor and a thyristor. At least one of the plurality of second modules is connected to at least one of the plurality of first modules.

Abstract: The multifunction wellbore conditioning tool (100, 200, 300) is installed in the bottom hole assembly of a drill string and performs the functions of a cutting tool, keyseat wiper, roller reamer, keyseat wiper, and stabilizer during drilling operations, precluding the need for multiple different tools in the drill string. The tool (100, 200, 300) has a working sleeve (114, 214, 314) captured concentrically on the driveshaft (102, 202, 302) between opposed spring sets (134, 136; 234, 236; 334, 336). The sleeve (114, 214, 314) remains rotationally stationary about the rotating driveshaft (102, 202, 302) when in its central or neutral position on the driveshaft (102, 202, 302). When the sleeve (114, 214, 314) shifts axially on the driveshaft (102, 202, 302) it engages a clutch mechanism that allows it to rotate with the driveshaft (102, 202, 302) so that the rotating working sleeve (114, 214, 314) conditions the borehole.

Abstract: An electrical converter is provided, comprising a first half-bridge sub-module, a switch, and a first capacitor. The half-bridge sub-module is connected to the first capacitor, and the switch is connected to a terminal of the first half-bridge sub-module.

Abstract: An electrical converter, comprising a plurality of first modules and a plurality of second modules. At least one of the plurality of first modules includes a half-bridge module coupled with a direct current (DC)-link capacitor. A diode connected across the DC-link capacitor and a thyristor. At least one of the plurality of second modules is connected to at least one of the plurality of first modules.

Abstract: Voltage balancing and extracted output power circuit topologies use maximum power point and maximum power point tracking to provide voltage balancing and voltage and current adjustment to optimize extracted output power for corresponding DC voltage source strings (120a, 130a). The topologies used to control power generation include one or more voltage balancing circuits and/or power system optimizer circuits (102a) to reduce decreased power utilization and enable independent operating voltages of DC voltage source strings (120a, 130a) to provide voltage balancing and to deliver a maximum power independent of the voltage and current of other DC voltage source strings (120a, 130a). The current flowing in each DC voltage source string is controlled by the duty ratio of the corresponding switch (101a, 108a). The circuit topologies can include a plurality of voltage balancing/power system optimizer circuits (102a).

Abstract: The method of converting high voltage AC lines into bipolar high voltage DC systems makes use of the three transmission lines (referred to as the positive pole, the negative pole, and the modulating pole) in an existing high voltage AC system as transmission lines in a bipolar high voltage DC system. When current from the power source is up to the thermal current limit of the transmission lines, the transmission lines operate in two-wire mode, where current is delivered in the positive pole and returned in the negative pole, the modulating pole being open. When power source current exceeds the thermal current limit, operation is in three-wire mode, alternating for predetermined periods between parallel configuration of the positive pole and the modulating pole to divide current for delivery to the load, and parallel configuration of the negative pole and the modulating pole, dividing the return current.

Abstract: Voltage balancing and extracted output power circuit topologies use maximum power point and maximum power point tracking to provide voltage balancing and voltage and current adjustment to optimize extracted output power for corresponding DC voltage source strings (120a, 130a). The topologies used to control power generation include one or more voltage balancing circuits and/or power system optimizer circuits (102a) to reduce decreased power utilization and enable independent operating voltages of DC voltage source strings (120a, 130a) to provide voltage balancing and to deliver a maximum power independent of the voltage and current of other DC voltage source strings (120a, 130a). The current flowing in each DC voltage source string is controlled by the duty ratio of the corresponding switch (101a, 108a). The circuit topologies can include a plurality of voltage balancing/power system optimizer circuits (102a).

Abstract: The drill string axial vibration attenuator (10) is installed in the bottom hole assembly (BHA) of a drill string to attenuate axial and torsional vibrations of the drill string. The vibration attenuator (10) includes a massive elongate stabilizer (14) installed in a sealed chamber (12) that is, in turn, rigidly installed within the BHA of the drill string. Clearance between the inner wall of the chamber (12) and the stabilizer (14) is provided to preclude frictional interference therebetween. The stabilizer mass (14) is supported from below by a compression spring (18) and a shock absorber or damper (24) at the top to allow movement of the mass (14). The stabilizer (14) substantially reduces or eliminates axial and coupled torsional vibration of the drill string when the mass of the stabilizer (14), the rate of the spring, and the damper stiffness are properly configured.

Abstract: The direct current (DC) side fault isolator for high voltage direct current (HVDC) converters (10) includes a first set of double thyristor switches (12) connected across the line-to-line voltage terminals between first and second phases of alternating current (AC) terminals of a HVDC converter (14), and a second set of double thyristor switches (12) connected across the line-to-line voltage between the second phase and a third phase of the AC terminals of the HVDC converter (14). In use, the first and second sets of double thyristor switches (12) separate the HVDC converter (10) from an external power grid (18) during direct current (DC) side faults by turning on these thyristors (12).

Abstract: The method of converting high voltage AC lines into bipolar high voltage DC systems makes use of the three transmission lines (referred to as the positive pole, the negative pole, and the modulating pole) in an existing high voltage AC system as transmission lines in a bipolar high voltage DC system. When current from the power source is up to the thermal current limit of the transmission lines, the transmission lines operate in two-wire mode, where current is delivered in the positive pole and returned in the negative pole, the modulating pole being open. When power source current exceeds the thermal current limit, operation is in three-wire mode, alternating for predetermined periods between parallel configuration of the positive pole and the modulating pole to divide current for delivery to the load, and parallel configuration of the negative pole and the modulating pole, dividing the return current.

Abstract: The direct current (DC) side fault isolator for high voltage direct current (HVDC) converters (10) includes a first set of double thyristor switches (12) connected across the line-to-line voltage terminals between first and second phases of alternating current (AC) terminals of a HVDC converter (14), and a second set of double thyristor switches (12) connected across the line-to-line voltage between the second phase and a third phase of the AC terminals of the HVDC converter (14). In use, the first and second sets of double thyristor switches (12) separate the HVDC converter (10) from an external power grid (18) during direct current (DC) side faults by turning on these thyristors (12).