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:
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 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:
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:
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 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. Once combined, the time domain semblances more accurately depict the slowness of an acoustic wave through the formation at the selected depth. In addition, a related self-adaptation method to compress the waveform data downhole for storage or transmission is also disclosed.