Abstract: Aspects of the present disclosure relate to a method for determining a contact angle, a wettability, or both, of one or more types of solid particles within a geological formation. The method may include identifying a relative conductive of the type of solid particles and identifying a frequency range for one or more EM measurements. The method may also include determining a contact angle associated with at least one type of solid particles within the geological formation using the electromagnetic measurements corresponding to the frequency range.

Abstract: Aspects of the present disclosure relate to a method for determining a wettability of one or more types of solid particles within a geological formation. The method may include receiving a plurality of electromagnetic measurements within a frequency range from an electromagnetic well-logging tool. The method may also include determining a contact angle associated with at least one type of solid particles within the geological formation using the electromagnetic measurements.

Abstract: A method comprises performing data pre-processing of initial signals to obtain pre-processed initial signals; building a first machine learning model based on the pre-processed initial signals; generating output signals using the first machine learning model; computing ranks of the output signals; computing classifications of the output signals; and building a set of stacked machine learning models based on the ranks and the classifications. The set of stacked machine learning models may be used to generate subsurface well log data, NMR data, or other data.

Abstract: An electromagnetic measurement tool for making multi-frequency, full tensor, complex, electromagnetic measurements includes a triaxial transmitter and a triaxial receiver deployed on a tubular member. An electronic module is configured to obtain electromagnetic measurements at four or more distinct frequencies. The measurement tool may be used for various applications including obtaining a resistivity of sand layers in an alternating shale-sand formation; computing a dielectric permittivity, a conductivity anisotropy, and/or a permittivity anisotropy of a formation sample; and/or identifying formation mineralization including discriminating between pyrite and graphite inclusions and/or computing weight percent graphite and/or pyrite in the formation sample.

Abstract: A method comprises obtaining temporal measurements associated with a heterogeneous material; building a numerical model of a material by assigning initial approximations to the temporal measurements; modifying the numerical model to create a modified numerical model; generating simulated temporal measurements associated with the temporal measurements using the modified numerical model; determining a reward, a penalty, or a modification based on a quality of a fit between the temporal measurements and the simulated temporal measurements; and updating the numerical model based on the reward, the penalty, or the modification.

Abstract: In one non-limiting embodiment, the present disclosure is directed to a controller having a memory; and a processor coupled to the memory and configured to: cause a neural network to receive current measurements of a current material; instruct the neural network to determine dominant features of the current measurements; instruct the neural network to provide the dominant features to a decoder; and instruct the decoder to generate a generated spectral response of the current material based on the dominant features. In another non-limiting embodiment, the present disclosure is directed to a method including the steps of receiving current measurements of a current material; determining dominant features of the current measurements; providing the dominant features; and generating a generated spectral response of the current material based on the dominant features.

Abstract: Aspects of the present disclosure relate to a method for determining a contact angle, a wettability, or both, of one or more types of solid particles within a geological formation. The method may include identifying a relative conductive of the type of solid particles and identifying a frequency range for one or more EM measurements. The method may also include determining a contact angle associated with at least one type of solid particles within the geological formation using the electromagnetic measurements corresponding to the frequency range.

Abstract: Aspects of the present disclosure relate to a method for determining a wettability of one or more types of solid particles within a geological formation. The method may include receiving a plurality of electromagnetic measurements within a frequency range from an electromagnetic well-logging tool. The method may also include determining a contact angle associated with at least one type of solid particles within the geological formation using the electromagnetic measurements.

Abstract: A method comprises obtaining temporal measurements associated with a heterogeneous material; building a numerical model of a material by assigning initial approximations to the temporal measurements; modifying the numerical model to create a modified numerical model; generating simulated temporal measurements associated with the temporal measurements using the modified numerical model; determining a reward, a penalty, or a modification based on a quality of a fit between the temporal measurements and the simulated temporal measurements; and updating the numerical model based on the reward, the penalty, or the modification.

Abstract: A method comprises performing data pre-processing of initial signals to obtain pre-processed initial signals; building a first machine learning model based on the pre-processed initial signals; generating output signals using the first machine learning model; computing ranks of the output signals; computing classifications of the output signals; and building a set of stacked machine learning models based on the ranks and the classifications. The set of stacked machine learning models may be used to generate subsurface well log data, NMR data, or other data.

Abstract: A method for determining a level of organic maturity of a shale gas formation includes inverting multifrequency complex conductivity data to estimate a volume fraction of graphite, turbostatic carbon nanostructures, and pyrite. The inversion is validated using estimates of the volume fraction of graphite, turbostatic carbon nanostructures, and pyrite. The volume fraction of graphite and turbostatic carbon nanostructures is correlated to a level of organic maturity log of the shale gas formation. The level of organic maturity log is validated using sulfur content obtained from pyrolysis or vitrinite reflectance. A variation of an electromagnetic response due to the volume fraction of graphite, turbostatic carbon nanostructures, and pyrite is quantified. The electromagnetic response is modified by removing the quantified variation to obtain resistivity and permittivity values.

Abstract: A method to estimate water saturation in electromagnetic measurements includes making an electromagnetic measurement and performing at least one of (a) creating an analytical forward model of the EM measurement, (b) creating a numerical finite difference forward model of the EM measurement, and (c) performing an inversion. The method also includes removing at least one petrophysically-adverse alteration of EM measurements in the frequency range from 1 Hz to 100 MHz. A petrophysically-adverse alteration is due to the presence of at least one of the following: pyrite, graphitic-precursors, magnetite, and other conductive minerals.

Abstract: In one non-limiting embodiment, the present disclosure is directed to a controller having a memory; and a processor coupled to the memory and configured to: cause a neural network to receive current measurements of a current material; instruct the neural network to determine dominant features of the current measurements; instruct the neural network to provide the dominant features to a decoder; and instruct the decoder to generate a generated spectral response of the current material based on the dominant features. In another non-limiting embodiment, the present disclosure is directed to a method including the steps of receiving current measurements of a current material; determining dominant features of the current measurements; providing the dominant features; and generating a generated spectral response of the current material based on the dominant features.

Abstract: An electromagnetic measurement tool for making multi-frequency, full tensor, complex, electromagnetic measurements includes a triaxial transmitter and a triaxial receiver deployed on a tubular member. An electronic module is configured to obtain electromagnetic measurements at four or more distinct frequencies. The measurement tool may be used for various applications including obtaining a resistivity of sand layers in an alternating shale-sand formation; computing a dielectric permittivity, a conductivity anisotropy, and/or a permittivity anisotropy of a formation sample; and/or identifying formation mineralization including discriminating between pyrite and graphite inclusions and/or computing weight percent graphite and/or pyrite in the formation sample.

Abstract: An electromagnetic measurement tool for making multi-frequency, full tensor, complex, electromagnetic measurements includes a triaxial transmitter and a triaxial receiver deployed on a tubular member. An electronic module is configured to obtain electromagnetic measurements at four or more distinct frequencies. The measurement tool may be used for various applications including obtaining a resistivity of sand layers in an alternating shale-sand formation; computing a dielectric permittivity, a conductivity anisotropy, and/or a permittivity anisotropy of a formation sample; and/or identifying formation mineralization including discriminating between pyrite and graphite inclusions and/or computing weight percent graphite and/or pyrite in the formation sample.

Abstract: A method for calibrating an electromagnetic core analysis tool is disclosed. The method includes disposing a tilted test loop inside of or outside of a tool having more than one antenna. A uniform test pack, a layered test pack, and an effective media test pack are each disposed in the tool. A signal is induced in a receiver antenna in the tool when a second antenna is energized with a known current of a known frequency. The induced signal is measured and a calibration gain and offset is determined. A corrected signal is produced and compared with the determined signal based on a forward model.

Abstract: A method to estimate water saturation in electromagnetic measurements includes making an electromagnetic measurement and performing at least one of (a) creating an analytical forward model of the EM measurement, (b) creating a numerical finite difference forward model of the EM measurement, and (c) performing an inversion. The method also includes removing at least one petrophysically-adverse alteration of EM measurements in the frequency range from 1 Hz to 100 MHz. A petrophysically-adverse alteration is due to the presence of at least one of the following: pyrite, graphitic-precursors, magnetite, and other conductive minerals.

Abstract: An electromagnetic measurement tool for making multi-frequency, full tensor, complex, electromagnetic measurements includes a triaxial transmitter and a triaxial receiver deployed on a tubular member. An electronic module is configured to obtain electromagnetic measurements at four or more distinct frequencies. The measurement tool may be used for various applications including obtaining a resistivity of sand layers in an alternating shale-sand formation; computing a dielectric permittivity, a conductivity anisotropy, and/or a permittivity anisotropy of a formation sample; and/or identifying formation mineralization including discriminating between pyrite and graphite inclusions and/or computing weight percent graphite and/or pyrite in the formation sample.

Abstract: A method for calibrating an electromagnetic core analysis tool is disclosed. The method includes disposing a tilted test loop inside of or outside of a tool having more than one antenna. A uniform test pack, a layered test pack, and an effective media test pack are each disposed in the tool. A signal is induced in a receiver antenna in the tool when a second antenna is energized with a known current of a known frequency. The induced signal is measured and a calibration gain and offset is determined. A corrected signal is produced and compared with the determined signal based on a forward model.

Abstract: A method for determining a level of organic maturity of a shale gas formation includes inverting multifrequency complex conductivity data to estimate a volume fraction of graphite, turbostatic carbon nanostructures, and pyrite. The inversion is validated using estimates of the volume fraction of graphite, turbostatic carbon nanostructures, and pyrite. The volume fraction of graphite and turbostatic carbon nanostructures is correlated to a level of organic maturity log of the shale gas formation. The level of organic maturity log is validated using sulfur content obtained from pyrolysis or vitrinite reflectance. A variation of an electromagnetic response due to the volume fraction of graphite, turbostatic carbon nanostructures, and pyrite is quantified. The electromagnetic response is modified by removing the quantified variation to obtain resistivity and permittivity values.