Abstract: A method for logging a formation or sample includes obtaining a plurality of multiaxial conductivity measurements from the formation or sample. A horizontal resistivity measurement, a dip measurement and a dip azimuth measurement are derived from the plurality of multiaxial conductivity measurements. A sharp vertical resistivity measurement is derived from a subset of the plurality of multiaxial conductivity measurements.

Abstract: A method to determine at least one formation property of a subterranean formation includes providing a downhole electromagnetic logging tool having at least one transmitter array and one receiver array to acquire measurements in the formation. The method further includes performing a first inversion in response to the measurements, assuming dip or dip azimuth is constant in an inversion zone within the formation to obtain an inverted formation model. The method includes determining an n-th order partial derivative matrix of at least one of dip or dip azimuth, wherein n is greater than or equal to 1. The method includes performing a second inversion using the determined n-th order partial derivative matrix, wherein at least one of dip and dip azimuth are allowed to vary in the inversion zone, to obtain an updated formation model. The method includes determining the formation property using the updated formation model.

Abstract: A system and method discloses performing a fracture operation at a wellsite about a subterranean formation. The method involves, obtaining wellsite measurements by placing a downhole tool in a wellbore and using the downhole tool to acquire measurements of the subterranean formation, simulating the obtained wellsite measurements to determine formation parameters comprising conductivity tensors based on a formation model of the measured subterranean formation, validating the formation model by comparing the obtained wellsite measurements with the simulated wellsite measurements, generating fracture parameters and triaxiality indicators based on the validated formation model, and fracturing the subterranean formation based on the generated fracture parameters and triaxiality indicators.

Abstract: A method for determining existence of a fracture in a formation surrounding a wellbore drilled through subsurface rock formations includes calculating vertical resistivity, horizontal resistivity, apparent formation dip, apparent formation azimuth and axial resistivity for a plurality of longitudinal instrument spacings using measurements from a triaxial induction well logging instrument disposed in the formation. A spread in the axial resistivity values is determined and the axial resistivity spread threshold therefrom. Fracture indicator values and fracture orientation values are calculated from transverse components of the triaxial induction measurements. Presence of a fracture is indicated when at least one of the fracture indicator value exceeds a selected threshold, the axial resistivity spread exceeds the spread threshold and when the apparent formation dip exceeds a selected threshold.

Abstract: The present disclosure relates to a method to determine a formation property of a subsurface formation. A downhole logging tool having two or more tri-axial antennas is provided and used to obtain azimuthally sensitive data. Borehole correction is performed on the obtained data and a ZD-inversion is performed on the borehole corrected data for all antenna spacing groups. A formation indicator flag is determined and, depending on the determined formation indicator flag, a 1D-axial inversion and/or a 1D-radial inversion is performed over selected zones, or neither is performed. The best ZD-inversion results are selected and the 1D-axial inversion results and/or the 1D-radial inversion results, if any, are combined with the selected best ZD-inversion results to form a composite inversion result. The formation property of the subsurface formation is determined using the composite inversion result.

Abstract: Techniques involve determining the frequency-dependent dielectric permittivity spectrum of a rock sample. Determining the frequency-dependent dielectric permittivity may involve defining a series of electromagnetic measurement data having at least a measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ?? can be obtained. The electromagnetic measurement data also includes measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained. Using these measurements, the frequency-dependent spectrum of the sample may be determined.

Abstract: A tool is for use in a borehole during drilling with a drilling fluid circulating in the borehole. The tool may include a housing, a plurality of spaced apart radio frequency (RF) transmitters carried by the housing, spaced apart RF receivers carried by the housing, and a controller to communicate with the plurality of transmitters and the receivers. The controller may, at a given depth within the borehole, determine attenuation resistivity measurements and phase-shift resistivity measurements both corresponding to different radial distances from the borehole. The controller may also determine when a fracture has occurred in the geological formation at the given depth allowing the drilling fluid to intrude into the geological formation based upon the attenuation resistivity measurements and the phase-shift resistivity measurements.

Abstract: A system and method of performing a fracture operation at a wellsite about a subterranean formation is disclosed. The method involves, obtaining wellsite measurements by placing a downhole tool in a wellbore and using the downhole tool to acquire measurements of the subterranean formation, simulating the obtained wellsite measurements to determine formation parameters comprising conductivity tensors based on a formation model of the measured subterranean formation, validating the formation model by comparing the obtained wellsite measurements with the simulated wellsite measurements, generating fracture parameters and triaxiality indicators based on the validated formation model, and fracturing the subterranean formation based on the generated fracture parameters and triaxiality indicators.

Abstract: A method to determine at least one formation property of a subterranean formation includes providing a downhole electromagnetic logging tool having at least one transmitter array and one receiver array and acquiring measurements in the formation using the transmitter and receiver arrays of the downhole electromagnetic logging tool. The method further includes performing a first inversion in response to the measurements, wherein at least one of dip or dip azimuth are assumed constant in an inversion zone within the formation to obtain an inverted formation model that comprises at least one of horizontal resistivity (Rh), vertical resistivity (Rv), dip, and dip azimuth. The method includes determining an n-th order partial derivative matrix of at least one of dip or dip azimuth, wherein n is greater than or equal to 1.

Abstract: Techniques involve determining the frequency-dependent dielectric permittivity spectrum of a rock sample. Determining the frequency-dependent dielectric permittivity may involve defining a series of electromagnetic measurement data having at least a measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ?? can be obtained. The electromagnetic measurement data also includes measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained. Using these measurements, the frequency-dependent spectrum of the sample may be determined.

Abstract: A method for logging a formation or sample includes obtaining a plurality of multiaxial conductivity measurements from the formation or sample. A horizontal resistivity measurement, a dip measurement and a dip azimuth measurement are derived from the plurality of multiaxial conductivity measurements. A sharp vertical resistivity measurement is derived from a subset of the plurality of multiaxial conductivity measurements.

Abstract: A method for determining the frequency-dependent dielectric permittivity spectrum of a rock sample, comprising:—defining a series of electromagnetic measurement data comprising at least a first measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ??, can be obtained; and at least second and third measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained; and—using the first, second and third measurements to determine the frequency-dependent spectrum of the sample.

Abstract: Methods and systems are provided for logging a formation by combining results for a zero-dimensional inversion of conductivity measurements with results for a higher-order inversion of a subset of the conductivity measurement. The higher order inversion can include a 1D-radial portion and a 1D-axial portion. The combined results can include formation characteristics such as Rh, Rv, dip, and azimuth.

Abstract: A method for determining spatial distribution of fluid injected into a subsurface rock formation includes injecting the fluid into the rock formation. The fluid includes therein electrically conductive solid particles dispersed in an electrolyte. An electromagnetic response of the formation is measured. The measured electromagnetic response is used to determine spatial distribution of the injected fluid.

Abstract: The present disclosure relates to a method to determine a formation property of a subsurface formation. A downhole logging tool having two or more tri-axial antennas is provided and used to obtain azimuthally sensitive data. Borehole correction is performed on the obtained data and a ZD-inversion is performed on the borehole corrected data for all antenna spacing groups. A formation indicator flag is determined and, depending on the determined formation indicator flag, a 1D-axial inversion and/or a 1D-radial inversion is performed over selected zones, or neither is performed. The best ZD-inversion results are selected and the 1D-axial inversion results and/or the 1D-radial inversion results, if any, are combined with the selected best ZD- inversion results to form a composite inversion result. The formation property of the subsurface formation is determined using the composite inversion result.

Abstract: A method for determining the frequency-dependent dielectric permittivity spectrum of a rock sample, comprising:—defining a series of electromagnetic measurement data comprising at least a first measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ??, can be obtained; and at least second and third measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained; and—using the first, second and third measurements to determine the frequency-dependent spectrum of the sample.

Abstract: A method for determining existence of a fracture in a formation surrounding a wellbore drilled through subsurface rock formations includes calculating vertical resistivity, horizontal resistivity, apparent formation dip, apparent formation azimuth and axial resistivity for a plurality of longitudinal instrument spacings using measurements from a triaxial induction well logging instrument disposed in the formation. A spread in the axial resistivity values is determined and the axial resistivity spread threshold therefrom. Fracture indicator values and fracture orientation values are calculated from transverse components of the triaxial induction measurements. Presence of a fracture is indicated when at least one of the fracture indicator value exceeds a selected threshold, the axial resistivity spread exceeds the spread threshold and when the apparent formation dip exceeds a selected threshold.

Abstract: A method for determining spatial distribution of fluid injected into a subsurface rock formation includes injecting the fluid into the rock formation. The fluid includes therein electrically conductive solid particles dispersed in an electrolyte. An electromagnetic response of the formation is measured. The measured electromagnetic response is used to determine spatial distribution of the injected fluid.

Abstract: A method for determining structural dip of subsurface formations includes accepting as input multiaxial induction measurements made by passing electric current through a multiaxial transmitter disposed in a wellbore drilled through subsurface rock formations. Voltages induced in a multiaxial receiver disposed at a longitudinally spaced apart location along the wellbore are detected while moving the transmitter and receiver along the wellbore. The multiaxial voltage measurements are inverted into values of formation dip magnitude and formation dip azimuth. A parameter related to shale content of the rock formations is measured, and structural dip of the rock formations is determined by selecting dip magnitude and dip azimuth values occurring when the parameter exceeds a selected threshold.

Abstract: An electromagnetic logging tool is disclosed that includes a support; and at least one four-coil array disposed on the support, wherein the at least one four-coil array comprises: a transmitter, a bucking coil, a receiver, and a trim coil. A method for balancing an induction array is disclosed that includes applying an alternating current to a transmitter of the induction array that comprises the transmitter, a bucking coil and a receiver; measuring a mutual coupling between the transmitter and the receiver; and adding an extra bucking coil, if the mutual coupling exceeds a selected criterion.