Abstract: Methods and systems are provided for characterizing interfacial tension (IFT) of reservoir fluids, which involves obtaining fluid property data that represents fluid properties of a reservoir fluid sample measured downhole at reservoir conditions, and inputting the fluid property data to a computational model that determines a value of oil-water IFT of the reservoir fluid sample based on the fluid property data. In embodiments, the fluid property data represents single-phase fluid properties of the reservoir fluid sample, such as fluid density and viscosity of an oil phase of the reservoir fluid sample and fluid density of a water phase of the reservoir fluid sample. In embodiments, the computation model can be based on machine learning or analytics combined with a thermodynamics-based physics model.

Abstract: To separate porosity from surface roughness, length scales for pore size and surface roughness are identified. These length scales are determined from surface roughness measurements and confirmed via NMR pore body calculations and pore size capillary pressure measurements. A filter removes pore contribution to surface roughness measurements and delivers intrinsic surface roughness. Additional filters and methods determine the minimum magnification on which to base surface roughness calculation, based on size of the field of view and where measured surface roughness approaches intrinsic surface roughness as magnification increases but larger magnification increase sampling time and difficulty. Sample irregularities, such as saw marks, are also filtered out or determined to be too large to remove via filter and another area of measurement is located. With the pore corrected quantification of surface roughness, surface relaxivity and pore distribution can be calculated with greater accuracy.

Abstract: Methods and systems are provided for clay detection, clay typing, and clay volume quantification using electromagnetic measurements on a porous media sample at a low frequency less than 5000 Hz. The electromagnetic measurements are used to determine and store permittivity data that characterizes permittivity of the porous media sample at the low frequency less than 5000 Hz. The low frequency electromagnetic measurements can be performed in a laboratory, at a wellsite or other surface location. The low frequency electromagnetic measurements are nondestructive, and the results indicate that the methods and systems are highly sensitive to the existence of clays.

Abstract: A method of estimating a wettability characteristic of a rock and fluid system includes acquiring a sample of the rock material, performing a first nuclear magnetic resonance (NMR) measurement of the sample when the sample is in a full water saturation condition, and measuring a first T2 distribution, performing a second NMR measurement of the sample when the sample is in a second partial saturation condition, and measuring a second T2 distribution. The method also includes separating a hydrocarbon component of the second T2 distribution from a water component of the second T2 distribution, applying a fluid substitution model to the water component of the second T2 distribution to generate a computed T2 distribution, and calculating a wettability index (WI) based on a difference between the first T2 distribution and the computed T2 distribution.

Abstract: Methods and systems are provided that employ a combination of dielectric dispersion measurement(s) and Nuclear Magnetic Resonance (NMR) measurement(s) to determine data that characterizes tortuosity of rock and data that characterizes tortuosity of fluid phases in the rock independently from one another.

Abstract: A method of estimating a material mechanical property of a porous material, for an application or objective with a specific application frequency and application strain amplitude, includes estimating an application frequency and an application strain amplitude for use in a targeted application or objective, and constructing a frequency transfer function relating the material mechanical property to measurement frequencies, the measurement frequency range including a measurement frequency different from the application frequency.

Abstract: Methods and systems are provided for clay detection, clay typing, and clay volume quantification using downhole electromagnetic measurements conducted by a downhole logging tool on a formation at a low frequency less than 5000 Hz. The downhole electromagnetic measurements are used to determine permittivity data that characterizes permittivity of the formation at the low frequency less than 5000 Hz. The downhole low frequency electromagnetic measurements are nondestructive, and the results indicate it is with high sensitivity to the existence of clays.

Abstract: Methods and systems are provided for characterizing interfacial tension (IFT) of reservoir fluids, which involves obtaining fluid property data that represents fluid properties of a reservoir fluid sample measured downhole at reservoir conditions, and inputting the fluid property data to a computational model that determines a value of oil-water IFT of the reservoir fluid sample based on the fluid property data. In embodiments, the fluid property data represents single-phase fluid properties of the reservoir fluid sample, such as fluid density and viscosity of an oil phase of the reservoir fluid sample and fluid density of a water phase of the reservoir fluid sample. In embodiments, the computation model can be based on machine learning or analytics combined with a thermodynamics-based physics model.

Abstract: Methods and systems are provided for characterizing formation water salinity of subsurface formation using multifrequency permittivity data over a range of frequencies below 1 MHz. The multifrequency permittivity data is processed to determine salinity of formation water contained in the subsurface formation. Other useful formation properties (such as formation water saturation) can be determined based on the formation water salinity.

Abstract: Methods and systems are provided for clay detection, clay typing, and clay volume quantification using downhole electromagnetic measurements conducted by a downhole logging tool on a formation at a low frequency less than 5000 Hz. The downhole electromagnetic measurements are used to determine permittivity data that characterizes permittivity of the formation at the low frequency less than 5000 Hz. The downhole low frequency electromagnetic measurements are nondestructive, and the results indicate it is with high sensitivity to the existence of clays.

Abstract: A method of estimating a material mechanical property of a porous material, for an application or objective with a specific application frequency and application strain amplitude, includes estimating an application frequency and an application strain amplitude for use in a targeted application or objective, and constructing a frequency transfer function relating the material mechanical property to measurement frequencies, the measurement frequency range including a measurement frequency different from the application frequency.

Abstract: To separate porosity from surface roughness, length scales for pore size and surface roughness are identified. These length scales are determined from surface roughness measurements and confirmed via NMR pore body calculations and pore size capillary pressure measurements. A filter removes pore contribution to surface roughness measurements and delivers intrinsic surface roughness. Additional filters and methods determine the minimum magnification on which to base surface roughness calculation, based on size of the field of view and where measured surface roughness approaches intrinsic surface roughness as magnification increases but larger magnification increase sampling time and difficulty. Sample irregularities, such as saw marks, are also filtered out or determined to be too large to remove via filter and another area of measurement is located. With the pore corrected quantification of surface roughness, surface relaxivity and pore distribution can be calculated with greater accuracy.

Abstract: Methods and systems are provided for clay detection, clay typing, and clay volume quantification using electromagnetic measurements on a porous media sample at a low frequency less than 5000 Hz. The electromagnetic measurements are used to determine and store permittivity data that characterizes permittivity of the porous media sample at the low frequency less than 5000 Hz. The low frequency electromagnetic measurements can be performed in a laboratory, at a wellsite or other surface location. The low frequency electromagnetic measurements are nondestructive, and the results indicate that the methods and systems are highly sensitive to the existence of clays.

Abstract: Methods and systems are provided that determine or estimate total clay volume fraction in a formation for well log data of the formation using machine learning are described. Methods and systems are also provided that employ computation models to determine amounts or concentrations of at least one clay mineral in the formation from total clay volume fraction of the formation.

Abstract: Methods and systems are provided for clay detection, clay typing, and clay volume quantification using downhole electromagnetic measurements conducted by a downhole logging tool on a formation at a low frequency less than 5000 Hz. The downhole electromagnetic measurements are used to determine permittivity data that characterizes permittivity of the formation at the low frequency less than 5000 Hz. The downhole low frequency electromagnetic measurements are nondestructive, and the results indicate it is with high sensitivity to the existence of clays.

Abstract: An array electromagnetic tool is run in a borehole, and resulting signals are processed to provide at least one of real and imaginary conductivity components, ?R* and ?I*. The at least one of real and imaginary conductivity components is compared to a corresponding representative conductivity component of a plurality of different clay groups and a determination of clay type in the formation is made therefrom.

Abstract: An array electromagnetic tool is run in a borehole, and resulting signals are processed to provide at least one of real and imaginary conductivity components, ?R* and ?I*. The at least one of real and imaginary conductivity components is compared to a corresponding representative conductivity component of a plurality of different clay groups and a determination of clay type in the formation is made therefrom.

Abstract: Methods and systems are described for using pulsed neutron ?-ray spectroscopy to measure formation water salinity from within a borehole. Through generating a cross-plot of database values of ratios of spectroscopically determined yields of hydrogen (H) and chlorine (Cl) from two detectors, deriving apparent salinities therefrom, formation and borehole water salinities can be determined.

Abstract: In-phase and quadrature components have different relationships with some important petrophyscial parameters, such as water saturation and mineral cation exchange capacity (CEC). In clay-containing subterranean rock formation such as shaly sand formations, these parameters can be estimated using different components of array induction tool data combined with other knowledge about the clay-containing formation. Some parameters, such as mobility and fraction of counterions are valid in cases where the pore water solution is an electrolyte of NaCl.

Abstract: The present disclosure describes various embodiments related to methods for determining salinity of water in a borehole of a formation and the water in the formation. Various methods may use inelastic and capture gamma-ray spectra obtained from a pulsed neutron logging tool. Various embodiments may use a ratio of chlorine from a capture spectrum to oxygen from an inelastic spectrum for a near and a far detector to calculate apparent salinity ratios for water in a borehole and a formation. From the apparent salinity ratios, a borehole salinity and a formation salinity may be calculated using a tool characterization database and without using formation water saturation for the calculation. Other embodiments may be disclosed or claimed.