Abstract: Methods, systems, devices, and products for acoustic detection in a borehole.

Abstract: A directional tool and method of surveying a wellbore with the directional tool in a borehole string. A first sensor of the directional tool is disposed in a non-homogeneous ambient magnetic field. A first applied magnetic field is applied to the first sensor. A first measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the first applied magnetic field applied. A second applied magnetic field is applied to the first sensor. A second measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the second applied magnetic field applied. The directional tool is calibrated based on the first and second measurement. A downhole survey measurement is obtained with the calibrated directional tool in the wellbore.

Abstract: A drilling system includes a method of determining an orientation of a drill string in a borehole. Sensor readings of a magnetic field of a drill bit are obtained at a plurality of positions along a curve extending around the drill bit along a longitudinal bit axis from a first location to a second location. A drill string includes the drill bit and a downhole magnetic field sensor that obtains a measurement of a local earth magnetic field, wherein the measurement is affected by the magnetic field of the drill bit. A processor determines a magnetic dipole moment of the drill bit from the plurality of sensor readings, calculates a second measurement of the local earth magnetic field downhole using the magnetic dipole moment of the drill bit, and determines the orientation of the drill string from the calculated correction of the measurement of the local earth magnetic field.

Abstract: Method for obtaining a directional survey in a rotating downhole component include acquiring and generating, while rotating, sets of raw data having 3-axis magnetic field data and 3-axis gravity field data. A set of rotationally-invariant data is obtained for each of the sets of raw data to generate a first number of sets of rotationally-invariant data. An earth property value is calculated from each of the sets. An accuracy indicator is estimated for each of the sets using a respective earth property value, an earth property reference value, and an error model, to generate a plurality of accuracy indicators. A set of mean values is determined using the plurality of sets of rotationally-invariant data using a second number of sets of rotationally-invariant data of the plurality of sets of rotationally-invariant data. The directional survey is estimated and used to control the downhole component.

Abstract: A method of estimating a directional parameter of a downhole component includes deploying a borehole string in a borehole, the borehole string including the downhole component, the downhole component being rotatable, the downhole component including a gyroscope device and a magnetometer device. The method also includes collecting gyroscope measurement data from the gyroscope device and magnetic field measurement data from the magnetometer device during rotation of the downhole component, and estimating, by a processor, the directional parameter of the downhole component, where the estimating includes correcting the gyroscope measurement data based on the magnetic field measurement data.

Abstract: Systems and methods for measuring a parameter of interest in a borehole in an earth formation are provided. The systems include a downhole sensor having a first sensor component with a first temperature and a second sensor component with a second temperature, the downhole sensor disposed on a downhole component. A temperature control system is configured with a thermal control mechanism operatively connected to at least one of the first and second sensor components. The thermal control mechanism is configured to maintain a temperature difference between the first temperature and the second temperature below a pre-determined temperature difference. The downhole sensor is configured to measure the parameter of interest when the temperature difference is below the pre-determined temperature difference.

Abstract: Methods, systems, devices, and products for acoustic detection in a borehole.

Abstract: A directional tool and method of surveying a wellbore with the directional tool in a borehole string. A first sensor of the directional tool is disposed in a non-homogeneous ambient magnetic field. A first applied magnetic field is applied to the first sensor. A first measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the first applied magnetic field applied. A second applied magnetic field is applied to the first sensor. A second measurement is obtained at the first sensor while the first sensor is disposed within the non-homogeneous ambient magnetic field and with the second applied magnetic field applied. The directional tool is calibrated based on the first and second measurement. A downhole survey measurement is obtained with the calibrated directional tool in the wellbore.

Abstract: A method of estimating a directional parameter of a downhole component includes deploying a borehole string in a borehole, the borehole string including the downhole component, the downhole component being rotatable, the downhole component including a gyroscope device and a magnetometer device. The method also includes collecting gyroscope measurement data from the gyroscope device and magnetic field measurement data from the magnetometer device during rotation of the downhole component, and estimating, by a processor, the directional parameter of the downhole component, where the estimating includes correcting the gyroscope measurement data based on the magnetic field measurement data.

Abstract: Systems and methods for measuring a parameter of interest in a borehole in an earth formation are provided. The systems include a downhole sensor having a first sensor component with a first temperature and a second sensor component with a second temperature, the downhole sensor disposed on a downhole component. A temperature control system is configured with a thermal control mechanism operatively connected to at least one of the first and second sensor components. The thermal control mechanism is configured to maintain a temperature difference between the first temperature and the second temperature below a pre-determined temperature difference. The downhole sensor is configured to measure the parameter of interest when the temperature difference is below the pre-determined temperature difference.

Abstract: Methods, systems, devices, and products for acoustic detection in a borehole.

Abstract: An optical component comprising at least one first waveguide having a first core and a casing surrounding the first core, and comprising at least one second waveguide having a second core, wherein the first core and the second core are guided adjacent and at a distance to one another in a longitudinal section, and at least one Bragg grating is arranged in said longitudinal section, and at least the first core, the first casing the second core and the Bragg grating are arranged in a single substrate.

Abstract: An optical component comprising at least one first waveguide having a first core and a casing surrounding the first core, and comprising at least one second waveguide having a second core, wherein the first core and the second core are guided adjacent and at a distance to one another in a longitudinal section, and at least one Bragg grating is arranged in said longitudinal section, and at least the first core, the first casing the second core and the Bragg grating are arranged in a single substrate.

Abstract: Methods, systems, devices, and products for estimating a parameter of interest of a downhole fluid in a borehole intersecting an earth formation. Apparatus include evanescent wave measurement instruments, which may include a substrate configured for contact with a downhole fluid such that at least a portion of the substrate is immersed in the downhole fluid; a waveguide formed in an interior of the substrate and having a configuration geometrically configured to generate an interaction between the downhole fluid and an evanescent wave arising from electromagnetic energy propagating in a segment of the waveguide; and a detector configured to generate measurement information indicative of the downhole fluid in response to electromagnetic signals received from the waveguide responsive to the interaction. The interaction may result in absorption of at least a portion of the electromagnetic energy propagating in the waveguide. The waveguide may be written in the substrate using laser pulses.

Abstract: Methods, systems, devices, and products for acoustic detection in a borehole.

Abstract: Methods, systems, devices, and products for estimating a parameter of interest of a downhole fluid in a borehole intersecting an earth formation. Apparatus include evanescent wave measurement instruments, which may include a substrate configured for contact with a downhole fluid such that at least a portion of the substrate is immersed in the downhole fluid; a waveguide formed in an interior of the substrate and having a configuration geometrically configured to generate an interaction between the downhole fluid and an evanescent wave arising from electromagnetic energy propagating in a segment of the waveguide; and a detector configured to generate measurement information indicative of the downhole fluid in response to electromagnetic signals received from the waveguide responsive to the interaction. The interaction may result in absorption of at least a portion of the electromagnetic energy propagating in the waveguide. The waveguide may be written in the substrate using laser pulses.