Abstract: The disclosure discloses an IGBT module reliability evaluation method and device based on bonding wire degradation, which belong to the field of IGBT reliability evaluation. The realization of the method includes: obtaining a relationship between a IGBT chip conduction voltage drop Uces and an operating current Ic along with a chip junction temperature Tc; for an IGBT module under test, obtaining the conduction voltage drop Uces-c of the IGBT chip through the operating current Ic and the chip junction temperature Tc; obtaining an external conduction voltage drop Uces-m of the IGBT module by using a voltmeter; performing subtraction to obtain a voltage drop at a junction of a IGBT chip and a bonding wire, and combining the operating current to obtain a resistance at the junction; determining that the IGBT module has failed when the resistance at the junction increases to 5% of an equivalent impedance of the IGBT module.

Abstract: An electromagnetic ranging system and method for location a target well. The electromagnetic ranging system may comprise a modular electromagnetic ranging tool. The electromagnetic ranging tool may comprise at least one transmitter coil and a receiver coil operable to measure at least one component of the electromagnetic field. An information handling system may be in signal communication with the modular electromagnetic ranging tool. A method for electromagnetic ranging of a target wellbore may comprise disposing a modular electromagnetic ranging tool in a wellbore, transmitting an electromagnetic field to the target wellbore from at least one transmitter coil disposed on the modular electromagnetic ranging tool, measuring at least one component of a secondary electromagnetic field, and determining a relative location of the target wellbore from at least measurements by the at least one receiver coil and one or more parameters of the at least one transmitter coil.

Abstract: An angular position sensor can include a magnetic device from which a magnetic field emanates, and multiple magnetometers, whereby each magnetometer senses a varying strength of the magnetic field due to relative rotation between components of a well tool. A method of determining an azimuthal position of a shaft which rotates relative to an outer housing can include securing a selected one of at least one magnetic device and at least one magnetometer to the shaft, securing the other of the magnetic device and the magnetometer to the outer housing, a fluid motor rotating the shaft relative to the outer housing in the well, and the magnetometer sensing a varying strength of a magnetic field emanating from the magnetic device as the shaft rotates relative to the housing.

Abstract: There is set forth herein a sensor for sensing of substances. The sensor can include a sensing crystal oscillator and a reference crystal oscillator. The sensing crystal oscillator and the reference crystal oscillator can be arranged in a phase locked loop so that the oscillators oscillate at a common frequency. The sensor can be configured so that there is a baseline phase differential between the oscillation frequencies of the sensing crystal oscillator and the reference crystal oscillator. Detectable substances accumulating on the sensing crystal oscillator will induce a phase shift between output frequencies of the reference oscillator and the sensing crystal oscillator to allow for highly sensitive sensing of substances in small concentrations.

Abstract: A method of determining the maximum temperature undergone by a specimen of sedimentary rock during natural heating over a geological process, within the range from 60° C. to 230° C. approximately. The method includes analysis at very low temperature, down to a few kelvin, for example down to 10 kelvin, of the magnetic transitions intended to characterize an iron oxide and an iron sulfide that are formed or destroyed in the specimen by the geological heating of the sediment; and determination of the maximum temperature undergone by the specimen, using a calibration obtained by measuring the same magnetic parameters on the same sediment or on other sediments of the same nature, heated beforehand in the laboratory to known temperatures.

Abstract: A logging tool for use in a borehole to obtain multicomponent resistivity induction measurements using collocated coils wherein each of the transverse antennas comprises a pair of mirror-image coils symmetrically disposed about an axis of the logging tool.

Abstract: A device for measuring alternating current (AC) magnetic susceptibility and the method for measuring the same are provided. The device comprises an AC magnetic susceptibility coil set, a signal capturing unit, and a signal processing unit. The device detects AC magnetic susceptibility signals from under testing particles in the magnetic field with variable AC frequencies, and extracts the AC magnetic susceptibility intensity variation and phase difference and/or the real part and the imaginary part of the AC magnetic susceptibility by the signal processing unit.

Abstract: A method for correcting subterranean resistivity measurements to account for tool bending includes processing at least one coupling component and at least one cross-coupling component in combination with a tool bending angle. Such processing may, for example, remove one or more coupling components from a cross-coupling component. Removal of the coupling component(s) tends to increase the sensitivity of directional resistivity measurements to remote boundaries.

Abstract: Methods and related systems are described for making electromagnetic measurements of a subterranean rock formation through a conductive casing of a borehole. A number of transmitters/receivers are deployed into single well having a conductive casing. A magnetic field is induced through the conductive casing and into a surrounding subterranean rock formation, and the magnetic field is detected by the receivers. The receivers have main windings, feedback winding and bucking windings. One of the receiver coils in the tool string is excited at a time, and induced voltages at all of the other receiver coils, either in straight mode, or in feedback mode, are measured.

Abstract: An induction logging tool is used on a MWD bottom hole assembly. Due to the finite, nonzero, conductivity of the mandrel, conventional multi frequency focusing (MFF) does not work. A correction is made to the induction logging data to give measurements simulating a perfectly conducting mandrel. MFF can then be applied to the corrected data to give formation resistivities.

Abstract: An apparatus and method for sensor signal prediction and for improving sensor signal response time, is disclosed. An adaptive filter or an artificial neural network is utilized to provide predictive sensor signal output and is further used to reduce sensor response time delay.

Abstract: A thermoregulated magnetic susceptibility sensor assembly for well-logging or the like is disclosed. The assembly includes a sensing solenoid and a non-metallic container for the sensing solenoid. Located in the container and spaced from the sensing solenoid are a plurality of heaters. These heaters are uniformly positioned about the sensing solenoid and a heat transfer material is located between the heaters and the sensing solenoid. The heat transfer material conducts the heat from the heaters to the sensing solenoid in a substantially uniform manner so that the sensing solenoid is maintained at a uniform temperature. Preferably, temperature sensors are provided to control the heat output of the heaters to maintain the sensing solenoid at the desired uniform temperature. To minimize heat transfer to the heaters from the external environment, a layer of insulation is provided around the heaters.

Abstract: Apparatus for continuously recording, as a function of the depth, the residual magnetization of the rocks through which a well hole passes, comprising, on the one hand, a measurement probe which contains means for measuring the magnetic susceptibility and the magnetic field and, in a cryostat, three gradiometers and, on the other hand, a processing unit which incorporates an integrator (81) for carrying out integration of the data from the gradiometers, a multiplier (76) for multiplying the magnetic field by the magnetic susceptibility, and a subtractor (83) for deducting this product from the result of the integration.

Abstract: A magnetic susceptibility log is run through an earth formation to identify the presence of any select non-magnetic minerals in association with magnetic minerals. The select non-magnetic mineral is identified as being present when the magnetic susceptibility measurement exceeds a level at which a measurable concentration of the select non-magnetic mineral is expected to be present.

Abstract: The probe comprises two inductance windings mounted in opposition and conted to an a.c. generator, a measurement winding placed at right angles between the two inductance windings and a measurement voltage detector. A compensation winding is placed coaxially and symmetrically with the measurement winding in relation to the axis of the inductance windings, thus permitting enhanced sensitivity of the probe and a directional effect. Potential applications include continuous recording of magnetic susceptibility along a vertical borehole wall and ore sorting on a conveyor belt.