Precision Energy Services, Inc.

Computalog Research, Inc.

Weatherford Technology Holdings, LLC

Computalog USA Inc.

Thomas Jay Blankinship

Lucio Nelson Tello

Margaret C Waid

Sean Michael Christian

Bryan William Kasperski

Jess V Ford

Elan Yogeswaren

Edwin K Roberts

Edwin Kamm Roberts

Dennis E Roessler

Christopher T Cotton

Allen R Young

Peter J Schoch

Marek Kozak

Gregory J Caston

Bryan Statt

Gerald T Alford

A method and apparatus for measuring parameters of a borehole using an acoustic logging system. By transmitting a high frequency acoustic signal essentially perpendicular to the major axis of a borehole casing using a transducer, the high frequency acoustic signal may produce one or more acoustic echoes. By receiving and analyzing a first acoustic echo from an inner wall of the borehole casing and at least one second acoustic echo from a back wall of the borehole casing, borehole parameters such as the impedance of the casing cement and the thickness of thicker borehole casings, up to and greater than 1 inch, may be determined.

Ultrasonic logging methods and apparatus for measuring cement and casing properties using acoustic echoes

Methods and systems for logging a wellbore having a casing are described. Acoustic energy, typically ultrasonic acoustic energy, is used to stimulate reverberation of the casing at a harmonic (for example, the second or third harmonic) of the resonance frequency of the casing. One or more acoustic sensors are used to measure acoustic signals generated by the casing reverberation. Parameters of the casing are calculated based on the measured acoustic signals adjusted by an adjustment factor determined by the particular harmonic. The use of harmonics instead of the fundamental resonance frequency allows wellbores with casings having walls thicker than 0.625 inches to be logged.

Ultrasonic cement and casing thickness evaluation

A method and apparatus for normalizing an acoustic wellbore tool by correcting measured sector acoustic signals due to changes in pressure and temperature downhole, the method and apparatus comprising an acoustic wellbore tool having at least one monopole transmitter and monopole receiver, and one or more sector transmitters and receivers disposed along the longitudinal axis of the tool, determining the attenuation values of received monopole and sector acoustic signals, determining a correction ratio using an average sector attenuation value and a theoretical attenuation value, and correcting the sector acoustic signals using the correction ratio.

Normalization of sector amplitudes using monopole amplitudes

A multi-channel detector assembly for downhole spectroscopy has a reference detector unit optically coupled to a reference channel of a source and has a measurement detector unit optically coupled to a measurement channel of the source. The reference and measurement detectors detect spectral signals across a spectral range of wavelengths from the reference and measurement channels. Conversion circuitry converts the detected spectral signals into reference signals and measurement signals, and control circuitry processes the reference and measurements signals based on a form of encoding used by the source. Then, the control circuitry can control the output of spectral signals from the source based on the processed signals or scale the measurement signal to correct for source fluctuations or changes in environmental conditions.

Multi-channel detector assembly for downhole spectroscopy

A refractive index sensor having one or more sources, an adaptive optical element or scanner, imaging optics, a sensing optic, and one or more detectors. The scanner impinges a signal from the source into the sensing optic and onto a sensor-sample interface at sequential angles of incidence. The detector response increases dramatically to signals reflected from the interface at corresponding sequential angles of reflection equal to or greater than a critical angle. The refractive index sensor also uses an input lens between the scanner and the sensing optic and uses an output lens between the sensing optic and the detector. A processor controls the sensor and can determine index of refraction of the fluid sample based on the detector response and scan rate. The sensor can be used in several operational environments from a laboratory to a downhole tool, such as a formation tester to determine properties in a borehole environment.

Refractive index sensor for fluid analysis

A multi-channel source assembly for downhole spectroscopy has individual sources that generate optical signals across a spectral range of wavelengths. A combining assembly optically combines the generated signals into a combined signal and a routing assembly that splits the combined signal into a reference channel and a measurement channel. Control circuitry electrically coupled to the sources modulates each of the sources at unique or independent frequencies during operation.

Multi-channel source assembly for downhole spectroscopy

An acoustic borehole logging system for generation and detection of multipole modes used to determine elastic properties of earth formations characterized as inhomogeneous anisotropic solids. The system concurrently generates and senses monopole, dipole, quadrupole and any higher order pole in the borehole/formation system in order to characterize the elastic properties and stress state of material penetrated by the borehole. Multipole modes of all orders are induced simultaneously without the need for separate transmitter and receiver systems. Performance of the logging system is not compromised due to eccentering of the axis of the tool in the borehole, tool tilt with respect to the axis of the borehole, or mismatch of response sensitivity of multiple receivers within the tool. The system comprises apparatus for generating and sensing acoustic signals in a borehole in an earth formation, and further comprises a processing method by which the sensor response signals are processed and analyzed to obtain desired formation parameters of interest.

Borehole apparatus and methods for simultaneous multimode excitation and reception to determine elastic wave velocities, elastic modulii, degree of anisotropy and elastic symmetry configurations

An acoustic logging system with a borehole tool comprising a transmitter assembly and an axially spaced receiver assembly. The transmitter and receiver assemblies are optionally rotatable with respect to each other, depending upon the embodiment of the logging system. The logging system is designed to measure, among other parameters, the velocity (or slowness) and amplitude of shear wave energy induced by the transmitter assembly within formation penetrated by the borehole. These parameters are extracted from full wave acoustic data responses of receiver elements comprising the receiver assembly, and are measured as a function of azimuth around the borehole. These parameters are subsequently used to determine anisotropic properties of the formation, such as the azimuthal direction of formation fracturing with respect to the well borehole. Optional rotation of the transmitter and receiver assemblies minimizes adverse effects of maintaining calibration and balance of multiple transmitters and receivers.

Method and apparatus for azimuthal logging of shear waves in boreholes using optionally rotatable transmitter and receiver assemblies

The acoustic impedance of a fluid in a borehole is determined by gating a reflected acoustic signal into a plurality of time slots, and comparing received energies of the signal for the time slots to obtain a value indicative of the acoustic impedance of the fluid. The value may be normalized to yield the acoustic impedance of the fluid using the acoustic impedance of, e.g., water as a calibration point. The acoustic pulse may be generated using a transducer immersed in an intermediate fluid contained within a chamber defined in part by a plate in contact with the borehole fluid and having a thickness such that a mechanical resonance frequency of the plate in a thickness mode is substantially equal to a resonance frequency of the transducer. The sonic velocity of the fluid is also measured and, when combined with the acoustic impedance, is used to determine fluid density.

Method and apparatus for acoustics logging of fluid density and wet cement plugs in boreholes

A method of determining the acoustic impedance of a fluid in a borehole, by gating a reflected acoustic signal into a plurality of time slots, and comparing received energies of the signal for the time slots to obtain a value indicative of the acoustic impedance of the fluid. The value may be normalized to yield the acoustic impedance of the fluid using the acoustic impedance of, e.g., water as a calibration point. The comparison is performed by comparing a ratio of an integration of a first ring down time slot and a second ring down time slot, to an integration of an internal reflection time slot. The acoustic pulse may be generated using a transducer immersed in an intermediate fluid contained within a chamber defined in part by a plate in contact with the borehole fluid and having a thickness such that a mechanical resonance frequency of the plate in a thickness mode is substantially equal to a resonance frequency of the transducer. The sonic velocity of the fluid is also measured and, when combined with the acoustic impedance, is used to determine the fluid density.

Method and apparatus for acoustic logging of fluid density and wet cement plugs in boreholes

Method and apparatus for acoustic logging of fluid density and wet

A production logging tool is provided for use within a well to directly measure a velocity profile of a multiphase fluid flow within a cross-section of a well. The production logging tool includes a tool housing from which a plurality of arms are radially extensible. The plurality of arms are rotatably mounted to the tool housing for rotating around a tool axis extending longitudinally through the tool housing. At least one Doppler flow sensor is fixedly mounted to one of the plurality of arms for moving with the arm to dispose the Doppler flow sensor within different localized regions within a cross-section of the well. The localized regions of the cross-section are located at different radial distances from and at different angular displacements around the tool axis of the tool housing, at points distal from the tool axis. The Doppler flow sensor has a depth of investigation for detecting flow velocities of a multiphase fluid flow proximate to the Doppler flow sensor, within the localized regions of the cross-section of the well. The plurality of arms are rotated about the tool housing to dispose the Doppler flow sensor within different ones of the localized regions disposed throughout the cross-section for measuring a velocity profile of the multiphase fluid flow through the cross-section of the well. Flow velocities are also preferably detected within localized regions disposed within the boundary layer of the multiphase fluid flow.

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Fort Worth, TX, United States of America

Thomas Jay Blankinship