Abstract: A method evaluating borehole subsurface geologies can include receiving a total response signal by a sensor array disposed in a borehole, the response signal represents a pressure wave propagating in the borehole. A secondary signal can be extracted from the total response signal and a depth location for at least one secondary source that corresponds to the secondary signal is determined. An estimated reflectivity response for the secondary signal as a function of frequency is determined and the estimated reflectivity response is inverted to determine the secondary source includes at least one of a potential fracture or a potential washout. The at least one of a fracture conductivity or a washout volume for the secondary source is compared to one or more borehole images corresponding to the depth location of the secondary source to determine the potential fracture is an actual fracture or the potential washout is an actual washout.

Abstract: Systems and methods are provided for identifying one or more properties of a rock formation. A system may be configured to receive sensor data obtained from one or more sensors, the sensor data generated from drilling operations performed in a wellbore, generate stress metrics and strain metrics for the sensor data based on a calibrated stress and strain map, and identify one or more properties of a rock formation based on the stress metrics and the strain metrics.

Abstract: This disclosure presents a method and process to improve the accuracy of the calculations for true vertical depth and Eastings and Northings pair of a borehole while drilling operations are in progress. The method utilizes continuous survey parameters that are collected while drilling operations are in progress, and that have been collected between two neighboring stationary survey parameters. The stationary survey parameters are assumed to be ground truth and are fused with an invertible solution to a low order polynomial to generate the true vertical depth and an Eastings and Northings pair at each continuous survey location. An objective function can be used to optimize and solve the polynomial. The method can be performed on a well site controller, a geo-steering system, a bottom hole assembly, or other computing system capable of receiving the collected measurements, performing the method steps, and communicating the resultant borehole position parameters to other systems.

Abstract: Systems and methods are provided for identifying one or more properties of a rock formation. A system may be configured to receive sensor data obtained from one or more sensors, the sensor data generated from drilling operations performed in a wellbore, generate stress metrics and strain metrics for the sensor data based on a calibrated stress and strain map, and identify one or more properties of a rock formation based on the stress metrics and the strain metrics.

Abstract: A method evaluating borehole subsurface geologies can include receiving a total response signal by a sensor array disposed in a borehole, the response signal represents a pressure wave propagating in the borehole. A secondary signal can be extracted from the total response signal and a depth location for at least one secondary source that corresponds to the secondary signal is determined. An estimated reflectivity response for the secondary signal as a function of frequency is determined and the estimated reflectivity response is inverted to determine the secondary source includes at least one of a potential fracture or a potential washout. The at least one of a fracture conductivity or a washout volume for the secondary source is compared to one or more borehole images corresponding to the depth location of the secondary source to determine the potential fracture is an actual fracture or the potential washout is an actual washout.

Abstract: An acoustic logging method that may comprise acquiring waveforms for multiple acoustic wave modes as a function of tool position in a borehole; deriving position-dependent mode dispersion curves from the waveforms; accessing a computed library of dispersion curves for a vertical shear slowness (s) and a Thomsen gamma (?) of a given acoustic wave mode as a function of frequency; interpolating dispersion curves in the computed library to an assumed known compressional wave slowness, a borehole radius, a formation density, a mud density, and a mud slowness; computing an adaptive weight; and inverting dispersion curve modes jointly for a shear wave anisotropy, a vertical shear wave slowness, an inverted mud slowness, and an inverted mud density as a function of depth. An acoustic logging system may comprise a logging tool, a conveyance attached to the logging tool, at least one sensor, and at least one processor.

Abstract: Systems and methods are provided for identifying one or more properties of a rock formation. A system may be configured to receive sensor data obtained from one or more sensors, the sensor data generated from drilling operations performed in a wellbore, generate stress metrics and strain metrics for the sensor data based on a calibrated stress and strain map, and identify one or more properties of a rock formation based on the stress metrics and the strain metrics.

Abstract: An acoustic logging method that may comprise acquiring waveforms for multiple acoustic wave modes as a function of tool position in a borehole; deriving position-dependent mode dispersion curves from the waveforms; accessing a computed library of dispersion curves for a vertical shear slowness (s) and a Thomsen gamma (?) of a given acoustic wave mode as a function of frequency; interpolating dispersion curves in the computed library to an assumed known compressional wave slowness, a borehole radius, a formation density, a mud density, and a mud slowness; computing an adaptive weight; and inverting dispersion curve modes jointly for a shear wave anisotropy, a vertical shear wave slowness, an inverted mud slowness, and an inverted mud density as a function of depth. An acoustic logging system may comprise a logging tool, a conveyance attached to the logging tool, at least one sensor, and at least one processor.

Abstract: An acoustic logging method includes obtaining first horizontal transverse isotropy (“HTI”) angles resulting from a time domain HTI algorithm. The method further includes obtaining one or more second HTI angles resulting from a frequency domain HTI algorithm. The method further includes generating a first HTI anisotropy log including a relative angle log based on the first and second HTI angles. The method further includes generating a first color map of the first HTI anisotropy log and displaying the first color map.

Abstract: Methods for well logging may comprise recording a pressure wave at a dipole receiver, processing the pressure wave with a Fourier transform, computing a frequency semblance from the Fourier transform, computing an adaptive weighting function, and estimating a shear wave slowness. A method for well logging may further comprise disposing a downhole tool into a borehole, activating the dipole transmitter, sensing the pressure wave with the dipole receiver, recording the pressure wave, processing the pressure wave with a Fourier transform, computing a frequency semblance from the Fourier transform, and estimating a shear wave slowness. Estimating shear wave slowness may comprise producing one or more adaptive weights, a combination of a coherence map, and a dispersion curve. Estimating shear wave slowness may further comprise preparing an acoustic well log from the adaptive weights, the combination of the coherence map, and the dispersion curve.

Abstract: An acoustic logging method includes obtaining first horizontal transverse isotropy (“HTI”) angles resulting from a time domain HTI algorithm. The method further includes obtaining one or more second HTI angles resulting from a frequency domain HTI algorithm. The method further includes generating a first HTI anisotropy log including a relative angle log based on the first and second HTI angles. The method further includes generating a first color map of the first HTI anisotropy log and displaying the first color map.

Abstract: Acoustic logging systems and methods are provided with multi-mode inversion for at least vertical shear slowness and shear anisotropy. At least some method embodiments acquire waveforms for multiple acoustic wave modes as a function of tool position in a borehole, derive position-dependent mode dispersion curves from the waveforms, match the derived dispersion curves with parameterized dispersion curves to determine a vertical shear slowness and a shear anisotropy as a function of position, and displaying a borehole log that represents at least one of the vertical shear slowness and the shear anisotropy as a function of position. The objective function employed for the inversion is evaluated across multiple wave propagation modes and mud slownesses and may employ an adaptive, frequency-dependent weighting based on distance between the derived dispersion curves and the parameterized dispersion curves.

Abstract: Acoustic logging systems and methods are provided with multi-mode inversion for at least vertical shear slowness and shear anisotropy. At least some method embodiments acquire waveforms for multiple acoustic wave modes as a function of tool position in a borehole, derive position-dependent mode dispersion curves from the waveforms, match the derived dispersion curves with parameterized dispersion curves to determine a vertical shear slowness and a shear anisotropy as a function of position, and displaying a borehole log that represents at least one of the vertical shear slowness and the shear anisotropy as a function of position. The objective function employed for the inversion is evaluated across multiple wave propagation modes and mud slownesses and may employ an adaptive, frequency-dependent weighting based on distance between the derived dispersion curves and the parameterized dispersion curves.