Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to measure a formation feature. An example apparatus includes a pre-processor to compare a first measurement obtained from a first sensor included in a logging tool at a first depth at a first time and a second measurement obtained from a second sensor included in the logging tool at the first depth at a second time. The example apparatus also include a semblance calculator to: calculate a correction factor based on a difference between the first measurement and the second measurement; and calculate a third measurement based on the correction factor and a fourth measurement obtained from the first sensor at a second depth at the second time. The example apparatus also includes a report generator to generate a report including the third measurement.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to measure a formation feature. An example apparatus includes a pre-processor to compare a first measurement obtained from a first sensor included in a logging tool at a first depth at a first time and a second measurement obtained from a second sensor included in the logging tool at the first depth at a second time. The example apparatus also include a semblance calculator to: calculate a correction factor based on a difference between the first measurement and the second measurement; and calculate a third measurement based on the correction factor and a fourth measurement obtained from the first sensor at a second depth at the second time. The example apparatus also includes a report generator to generate a report including the third measurement.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to measure a formation feature. An example apparatus includes a pre-processor to compare a first measurement obtained from a first sensor included in a logging tool at a first depth at a first time and a second measurement obtained from a second sensor included in the logging tool at the first depth at a second time. The example apparatus also include a semblance calculator to: calculate a correction factor based on a difference between the first measurement and the second measurement; and calculate a third measurement based on the correction factor and a fourth measurement obtained from the first sensor at a second depth at the second time. The example apparatus also includes a report generator to generate a report including the third measurement.

Abstract: Methods for correcting eccentering effects on echoes detected from ultrasonic pulses emitted by a transducer of a downhole tool. Echo envelope amplitude, azimuth, and location for each echo is utilized to assess echo amplitude sensitivity to geometric and spatial characteristics of the downhole tool within the wellbore. Echo envelope amplitudes are corrected for eccentering effects based on the assessed sensitivity. A visual representation of the corrected echo envelope amplitudes is the generated. Also disclosed herein are tangible, non-transient, computer-readable media comprising instructions executable by a processor to carry out the methods, as well as systems including downhole tools and processing devices operable to carry out the methods.

Abstract: Apparatus and methods for identifying drilling cuttings downhole by extracting an echo from a pulse-echo waveform acquired utilizing a downhole ultrasonic tool having an acoustic device. An energy before echo profile preceding the extracted echo is determined, and then the energy before echo profile is processed to remove effects associated with the acoustic device. A cutting is then identified from the processed energy before echo profile.

Abstract: Methods for correcting eccentering effects on echoes detected from ultrasonic pulses emitted by a transducer of a downhole tool. Echo envelope amplitude, azimuth, and location for each echo is utilized to assess echo amplitude sensitivity to geometric and spatial characteristics of the downhole tool within the wellbore. Echo envelope amplitudes are corrected for eccentering effects based on the assessed sensitivity. A visual representation of the corrected echo envelope amplitudes is the generated. Also disclosed herein are tangible, non-transient, computer-readable media comprising instructions executable by a processor to carry out the methods, as well as systems including downhole tools and processing devices operable to carry out the methods.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to measure a formation feature. An example apparatus includes a pre-processor to compare a first measurement obtained from a first sensor included in a logging tool at a first depth at a first time and a second measurement obtained from a second sensor included in the logging tool at the first depth at a second time. The example apparatus also include a semblance calculator to: calculate a correction factor based on a difference between the first measurement and the second measurement; and calculate a third measurement based on the correction factor and a fourth measurement obtained from the first sensor at a second depth at the second time. The example apparatus also includes a report generator to generate a report including the third measurement.

Abstract: Apparatus and methods for identifying drilling cuttings downhole by extracting an echo from a pulse-echo waveform acquired utilizing a downhole ultrasonic tool having an acoustic device. An energy before echo profile preceding the extracted echo is determined, and then the energy before echo profile is processed to remove effects associated with the acoustic device. A cutting is then identified from the processed energy before echo profile.

Abstract: An example method for automatically characterizing an echo contained in an ultrasonic signal generated with an ultrasonic transducer can include receiving data corresponding to the ultrasonic signal, calculating an energy ratio of the ultrasonic signal and localizing the echo using the energy ratio. The method can include windowing a portion of the ultrasonic signal around the localized echo and calculating a Fast Fourier Transform (FFT) and a Hilbert envelop of the windowed portion. The method can include estimating M echo parameters from the FFT and the Hilbert envelope of the windowed portion, where each of the M parameter vectors includes a plurality of echo parameters, calculating M parametric echo models based on each of the M echo parameter vectors and iteratively minimizing a difference between the windowed portion of the ultrasonic signal and a sum of the M parametric echo models.

Abstract: An example method for automatically characterizing an echo contained in an ultrasonic signal generated with an ultrasonic transducer can include receiving data corresponding to the ultrasonic signal, calculating an energy ratio of the ultrasonic signal and localizing the echo using the energy ratio. The method can include windowing a portion of the ultrasonic signal around the localized echo and calculating a Fast Fourier Transform (FFT) and a Hilbert envelop of the windowed portion. The method can include estimating M echo parameters from the FFT and the Hilbert envelope of the windowed portion, where each of the M parameter vectors includes a plurality of echo parameters, calculating M parametric echo models based on each of the M echo parameter vectors and iteratively minimizing a difference between the windowed portion of the ultrasonic signal and a sum of the M parametric echo models.