Abstract: A downhole borehole imaging tool and methods for determining a borehole size includes a magnetoresistive system and a hub moveably coupled to a fixed tool string. The hub includes a magnet. The magnetoresistive system includes magnetoresistive sensors disposed within the fixed tool string and segregated from the magnet. During operation, a routine scan of all sensors measures, for example, the output voltage V, angle ? of magnetic field, and temperature. Measurements from each sensor may then be characterized to account for temperature and input voltages variation of the sensors. The most accurate measurement can be used to derive the position of the hub 44 using the previous baseline parameters stored in the tool.

Abstract: A downhole borehole imaging tool and methods for determining a borehole size includes a magnetoresistive system and a hub moveably coupled to a fixed tool string. The hub includes a magnet. The magnetoresistive system includes magnetoresistive sensors disposed within the fixed tool string and segregated from the magnet. During operation, a routine scan of all sensors measures, for example, the output voltage V, angle ? of magnetic field, and temperature. Measurements from each sensor may then be characterized to account for temperature and input voltages variation of the sensors. The most accurate measurement can be used to derive the position of the hub 44 using the previous baseline parameters stored in the tool.

Abstract: A tool for use in a borehole in a geological formation may include a chassis, a drill collar surrounding the chassis, a port plug coupled between the drill collar and the chassis, RF antennas carried by the drill collar, and a multi-chip module (MCM) electronics package(s). The electronics package(s) may include a hermetically sealed electronics housing positioned between the chassis and the drill collar, a substrate within the electronics housing, RF transmitter circuitry on the substrate to cooperate with at least one first RF antenna to transmit RF signals into the geological formation, and RF receiver circuitry on the substrate to cooperate with at least one second RF antenna to receive RF signals from the geological formation. Furthermore, an electronics housing mount may couple the electronics housing with the port plug, and the electronics housing mount may have a passageway extending therethrough for receiving the port plug.

Abstract: A downhole tool includes a logging tool. The logging tool includes a spring integral with a sensor. The spring applies the sensor to a formation wall. Additionally, the spring includes a groove formed along a neutral axis thereof. In addition, a wire is located within the groove and is operatively connected with the sensor and at least one other component of the logging tool.

Abstract: A tool for use in a borehole in a geological formation may include a chassis, a drill collar surrounding the chassis, a port plug coupled between the drill collar and the chassis, RF antennas carried by the drill collar, and a multi-chip module (MCM) electronics package(s). The electronics package(s) may include a hermetically sealed electronics housing positioned between the chassis and the drill collar, a substrate within the electronics housing, RF transmitter circuitry on the substrate to cooperate with at least one first RF antenna to transmit RF signals into the geological formation, and RF receiver circuitry on the substrate to cooperate with at least one second RF antenna to receive RF signals from the geological formation. Furthermore, an electronics housing mount may couple the electronics housing with the port plug, and the electronics housing mount may have a passageway extending therethrough for receiving the port plug.

Abstract: A downhole tool includes a logging tool. The logging tool includes a spring integral with a sensor. The spring applies the sensor to a formation wall. Additionally, the spring includes a groove formed along a neutral axis thereof. In addition, a wire is located within the groove and is operatively connected with the sensor and at least one other component of the logging tool.

Abstract: A downhole tool includes a position system. The position system includes a hub moveably coupled to a fixed tool string. The hub includes a sensor component. The position system also includes a position sensor disposed within the fixed tool string and segregated from the sensor component. Additionally, the sensor component is at a first pressure and the position sensor is at a second pressure, different than the first pressure.

Abstract: Systems and methods for antenna transmitter health determinations and borehole compensation for an electromagnetic measurement tools are provided. The input current to an antenna transmitter of an electromagnetic measurement tool may be measured using a current measurement circuit. An output voltage proportional to the input current may be provided and compared to a threshold to determine the health of the antenna transmitter. A replacement borehole compensation matrix for calculating a combined attenuation measurement may be selected based on an identified unhealthy antenna transmitter.

Abstract: The present disclosure relates to a method to determine the phase of a signal when transmitter and receiver circuits use separate clocks. A discrepancy between the separate clocks is determined, as is a correction factor between the separate clocks. The phase is determined using a measured time of arrival of the signal, the determined discrepancy, and the determined correction factor. A drift factor and an expected start time of a pulse sequence may be used to determine the discrepancy. A start time of a pulse within the pulse sequence is determined and used to determine the correction factor. The method works by either absolute synchronization of the separate clocks, or by making the measurements independent of clock synchronization.

Abstract: Subsurface formation evaluation comprising, for example, sealing a portion of a wall of a wellbore penetrating the formation, forming a hole through the sealed portion of the wellbore wall, injecting an injection fluid into the formation through the hole, and determining a saturation of the injection fluid in the formation by measuring a property of the formation proximate the hole while maintaining the sealed portion of the wellbore wall.

Abstract: The present disclosure relates to a method to determine the phase of a signal when transmitter and receiver circuits use separate clocks. A discrepancy between the separate clocks is determined, as is a correction factor between the separate clocks. The phase is determined using a measured time of arrival of the signal, the determined discrepancy, and the determined correction factor. A drift factor and an expected start time of a pulse sequence may be used to determine the discrepancy. A start time of a pulse within the pulse sequence is determined and used to determine the correction factor. The method works by either absolute synchronization of the separate clocks, or by making the measurements independent of clock synchronization.

Abstract: A combined resistivity tool incorporating both induction/propagation antennas and lateral resistivity antennas disposed in recesses of downhole tubulars, in which a lateral resistivity antenna includes an insulating base layer disposed in the recess; a toroidal antenna disposed over the insulating base layer; and a shield disposed over the recess.

Abstract: Subsurface formation evaluation comprising, for example, sealing a portion of a wall of a wellbore penetrating the formation, forming a hole through the sealed portion of the wellbore wall, injecting an injection fluid into the formation through the hole, and determining a saturation of the injection fluid in the formation by measuring a property of the formation proximate the hole while maintaining the sealed portion of the wellbore wall.

Abstract: A combined resistivity tool incorporating both induction/propagation antennas and lateral resistivity antennas disposed in recesses of downhole tubulars, in which a lateral resistivity antenna includes an insulating base layer disposed in the recess; a toroidal antenna disposed over the insulating base layer; and a shield disposed over the recess.

Abstract: A combined resistivity tool incorporating both induction/propagation antennas and lateral resistivity antennas disposed in recesses of downhole tubulars, in which a lateral resistivity antenna includes an insulating base layer disposed in the recess; a toroidal antenna disposed over the insulating base layer; and a shield disposed over the recess.

Abstract: An apparatus for logging a formation traversed by a borehole includes a plurality of logging tools adapted for conveyance inside the borehole. The plurality of logging tools includes a tool body, a sensing pad responsive to a density property of the formation coupled to the tool body, a current emitting measure electrode responsive to a lateral resistivity property of the formation incorporated on the sensing pad, a mechanism for urging the sensing pad in contact with a side of the borehole coupled to the tool body, and a pair of mass isolation bands disposed about the tool body to isolate a mass of the tool body adjacent the measure electrode.

Abstract: A borehole caliper tool includes a tool body and an arm coupled to the tool body. The arm is deflectable relative to the tool body. The caliper tool further includes a cam coupled to the arm such that a position of the cam changes as the arm deflects. The caliper tool further includes a proximity sensor for sensing the position of the cam, wherein the position of the cam provides an indication of the deflection of the arm relative to the tool body.

Abstract: A borehole caliper tool includes a tool body, a bow spring flexibly coupled to the tool body, a target coupled to the bow spring, and an ultrasonic transducer coupled to the tool body, wherein in operation the ultrasonic transducer transmits an acoustic pulse to the target and receives an echo of the acoustic pulse from the target.

Abstract: The present invention describes a method and apparatus to control the effect of contact impedance on a formation resistivity measurement during a logging-while-drilling operation. The control of contact impedance is accomplished by maintaining a substantially zero difference in potential between two monitor electrodes positioned on the resistivity logging tool near a current electrode. The tool can employ a ring electrode configuration and/or a button electrode, configuration. The ring electrode configuration incorporates two pairs of ring monitor electrodes on each side of a ring current electrode. The button electrode configuration incorporates. a monitor electrode, surrounded by a current electrode, surrounded by a second monitor electrode. Insulation gaps are positioned between each electrode to separate the electrodes. A variable current is supplied to the current electrode in each configuration to maintain the same potential at each monitor electrode.

Abstract: A method of removing excess MCrAlY overlay coating from within a cooling hole of an aluminide coated gas turbine engine component is disclosed. The method includes providing a gas turbine engine component having an internal surface (4), an outer surface (6) and a root end (8). The component also includes at least one cooling hole (10) extending from the internal surface (4) to the outer surface (6), wherein the internal surface(4) of the component is coated with a corrosion resistant aluminide coating. An MCrAlY overlay coating (12) is also located on the outer surface (6) and inside a portion of the cooling hole (10).