Abstract: Methods and systems for gathering, deriving, and displaying the azimuthal brittleness index of a borehole. At least some embodiments include various methods for calculating and displaying borehole measurements in real-time for geosteering and drilling operations. At least one disclosed method embodiment for calculating and displaying azimuthal brittleness includes taking measurements of compressional and shear wave velocities as a function of position and orientation from inside the borehole. These velocity measurements are taken by a azimuthal sonic tool. Azimuthal brittleness is then derived based at least in part on the compressional and shear wave velocities.

Abstract: A method of generating an axial shear wave in a formation surrounding a wellbore comprising urging a clamp pad into contact with a wall of the wellbore, and applying an axial force to the clamp pad to impart a shear force into the wall of the wellbore to generate a shear wave in the formation.

Abstract: Methods and systems for gathering, deriving, and displaying the azimuthal brittleness index of a borehole. At least some embodiments include various methods for calculating and displaying borehole measurements in real-time for geosteering and drilling operations. At least one disclosed method embodiment for calculating and displaying azimuthal brittleness includes taking measurements of compressional and shear wave velocities as a function of position and orientation from inside the borehole. These velocity measurements are taken by a azimuthal sonic tool. Azimuthal brittleness is then derived based at least in part on the compressional and shear wave velocities.

Abstract: Multimodal geosteering systems and methods are disclosed. Some disclosed tool embodiments include first and second transmitter-receiver arrangements that make geosteering measurements using different forms of energy (such as acoustic and electromagnetic energy) to provide geosteering measurements that at least indicate a boundary direction but may also indicate a boundary distance. Some disclosed method embodiments include: determining a direction to a bed boundary using measurements with different energy types; and adjusting a drilling direction based at least in part on said determination. Combinations of (or selections between) the different measurements may be made based on, inter alia, measurement range, resolution, and contrast. Some disclosed system embodiments include a memory and a processor. The memory stores geosteering display software that configures the processor to generate an image with different regions based on the different types of geosteering measurements.

Abstract: A method of generating an axial shear wave in a formation surrounding a wellbore comprising urging a clamp pad into contact with a wall of the wellbore, and applying an axial force to the clamp pad to impart a shear force into the wall of the wellbore to generate a shear wave in the formation.

Abstract: A tool and processing system to provide an acoustic radial profile. A frequency semblance is performed on received time signals obtained from an array of acoustic receivers (FIG. 2, blocks 204, 206) so as to provide a set of frequency semblance values in frequency-slowness coordinate space. These frequency semblance values are transformed to a set of frequency semblance values in wavelength-slowness coordinate space (FIG. 2, block 208), from which a radial profile (FIG. 2, block 210) may be provided by utilizing a relationship between wavelength and radial depth.

Abstract: Multimodal geosteering systems and methods are disclosed. Some disclosed tool embodiments include first and second transmitter-receiver arrangements that make geosteering measurements using different forms of energy (such as acoustic and electromagnetic energy) to provide geosteering measurements that at least indicate a boundary direction but may also indicate a boundary distance. Some disclosed method embodiments include: determining a direction to a bed boundary using measurements with different energy types; and adjusting a drilling direction based at least in part on said determination. Combinations of (or selections between) the different measurements may be made based on, inter alia, measurement range, resolution, and contrast. Some disclosed system embodiments include a memory and a processor. The memory stores geosteering display software that configures the processor to generate an image with different regions based on the different types of geosteering measurements.

Abstract: A method is disclosed that may include separating modes in a plurality of coherent time-domain signals to form a plurality of separated modes, generating frequency coherence information for each of the plurality of separated modes, and combining the frequency coherence information for each of the plurality of separated modes to form combined frequency coherence information. An apparatus and system may include a processor and a storage device that can be encoded with computer-readable instructions, wherein the instructions when read and executed by the processor may include activities such as separating modes in a plurality of coherent time-domain signals, and recombining the modes in a frequency domain.

Abstract: A method is disclosed that may include separating modes in a plurality of coherent time-domain signals to form a plurality of separated modes, generating frequency coherence information for each of the plurality of separated modes, and combining the frequency coherence information for each of the plurality of separated modes to form combined frequency coherence information. An apparatus and system may include a processor and a storage device that can be encoded with computer-readable instructions, wherein the instructions when read and executed by the processor may include activities such as separating modes in a plurality of coherent time-domain signals, and recombining the modes in a frequency domain.

Abstract: A self-adaptable data compression technique includes compressing the digital data points of a waveform according to at least a first protocol and a second protocol, and various comparing the compressed data under various protocols to determine which would require the least memory for storage.

Abstract: A method for creating a frequency domain semblance for use in conjunction with acoustic logging tools is disclosed. Such a frequency domain semblance may be obtained by transforming an acoustic signal received at multiple depths into the frequency domain, combining the received waveforms corresponding to the different depth, and expressing the result in a graph with slowness and frequency axes. This graph shows the frequency-slowness location for the acoustic signal, as well as for other related signals that may inadvertently be generated by the acoustic logging tool. This information may then be used to more clearly measure the slowness of the received acoustic signal. Another aspect of the invention is the treatment of two or more time domain semblances as probability density functions of the slowness for an acoustic signal. This enables the combination of time domain semblances from the same depth in the wellbore.

Abstract: A method for creating a frequency domain semblance for use in conjunction with acoustic logging tools is disclosed. Such a frequency domain semblance may be obtained by transforming an acoustic signal received at multiple depths into the frequency domain, combining the received waveforms corresponding to the different depth, and expressing the result in a graph with slowness and frequency axes. This graph shows the frequency-slowness location for the acoustic signal, as well as for other related signals that may inadvertently be generated by the acoustic logging tool. This information may then be used to more clearly measure the slowness of the received acoustic signal. Another aspect of the invention is the treatment of two or more time domain semblances as probability density functions of the slowness for an acoustic signal. This enables the combination of time domain semblances from the same depth in the wellbore.

Abstract: A method for creating a frequency domain semblance for use in conjunction with acoustic logging tools is disclosed. Such a frequency domain semblance may be obtained by transforming an acoustic signal received at multiple depths into the frequency domain, combining the received waveforms corresponding to the different depth, and expressing the result in a graph with slowness and frequency axes. This graph shows the frequency-slowness location for the acoustic signal, as well as for other related signals that may inadvertently be generated by the acoustic logging tool. This information may then be used to more clearly measure the slowness of the received acoustic signal. Another aspect of the invention is the treatment of two or more time domain semblances as probability density functions of the slowness for an acoustic signal. This enables the combination of time domain semblances from the same depth in the wellbore.

Abstract: A method for creating a frequency domain semblance for use in conjunction with acoustic logging tools is disclosed. Such a frequency domain semblance may be obtained by transforming an acoustic signal received at multiple depths into the frequency domain, combining the received waveforms corresponding to the different depth, and expressing the result in a graph with slowness and frequency axes. This graph shows the frequency-slowness location for the acoustic signal, as well as for other related signals that may inadvertently be generated by the acoustic logging tool. This information may then be used to more clearly measure the slowness of the received acoustic signal. Another aspect of the invention is the treatment of two or more time domain semblances as probability density functions of the slowness for an acoustic signal. This enables the combination of time domain semblances from the same depth in the wellbore.