Abstract: Systems and techniques are provided for integrating laboratory generated nuclear magnetic resonance (NMR) data and NMR logging data. An example method can include obtaining NMR logging data describing one or more downhole NMR measurements captured during a drilling operation in a borehole; modifying the NMR logging data to be compatible with a temperature correction algorithm, yielding modified NMR logging data, the temperature correction algorithm having been determined based on laboratory generated NMR data; and applying the temperature correction algorithm to the modified NMR logging data, yielding temperature corrected NMR logging data.

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 for simulation of hydrocarbon systems having a sharply varying viscosity gradient include receiving, by a computer system, Neutron Magnetic Resonance (NMR) logs for hydrocarbon wells in an oilfield. The computer system identifies viscosity regions of hydrocarbons present within the hydrocarbon wells based on the NMR logs. The computer system determines equation of state (EOS) parameters based on compositional analysis of pressure-volume-temperature (PVT) samples obtained from the hydrocarbon wells. The computer system generates a three-dimensional (3D) model of the oilfield, using as inputs, the viscosity regions, the EOS parameters, and a fluid composition gradient with respect to a depth within each viscosity region. The computer system determines a landing depth from the surface of the Earth for operation of peripheral water injectors based on simulating the 3D viscosity model.

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 for simulation of hydrocarbon systems having a sharply varying viscosity gradient include receiving, by a computer system, Neutron Magnetic Resonance (NMR) logs for hydrocarbon wells in an oilfield. The computer system identifies viscosity regions of hydrocarbons present within the hydrocarbon wells based on the NMR logs. The computer system determines equation of state (EOS) parameters based on compositional analysis of pressure-volume-temperature (PVT) samples obtained from the hydrocarbon wells. The computer system generates a three-dimensional (3D) model of the oilfield, using as inputs, the viscosity regions, the EOS parameters, and a fluid composition gradient with respect to a depth within each viscosity region. The computer system determines a landing depth from the surface of the Earth for operation of peripheral water injectors based on simulating the 3D viscosity model.

Abstract: Provided in some embodiments are systems and methods for determining characteristics of a hydrocarbon reservoir. Embodiments include conducting a nuclear magnetic resonance (NMR) logging operation of a targeted reservoir section of a wellbore extending into a hydrocarbon reservoir to generate a NMR log of the targeted reservoir section, conducting a resistivity logging of the targeted reservoir section to generate an uninvaded water saturation (Sw) log of the targeted reservoir section, determining for each of a plurality of depths in the section, a T2 cutoff point based on values of the NMR and Sw logs, identifying a subset of the T2 cutoff points that exhibit a hyperbolic trend, determining a theoretical cutoff curve corresponding to the subset of the T2 cutoff points, determining a free water level (FWL) of the reservoir based on the theoretical cutoff curve, and determining a rock type of the reservoir based on the theoretical cutoff curve.

Abstract: Provided in some embodiments are systems and methods for determining characteristics of a hydrocarbon reservoir. Embodiments include conducting a nuclear magnetic resonance (NMR) logging operation of a targeted reservoir section of a wellbore extending into a hydrocarbon reservoir to generate a NMR log of the targeted reservoir section, conducting a resistivity logging of the targeted reservoir section to generate an uninvaded water saturation (Sw) log of the targeted reservoir section, determining for each of a plurality of depths in the section, a T2 cutoff point based on values of the NMR and Sw logs, identifying a subset of the T2 cutoff points that exhibit a hyperbolic trend, determining a theoretical cutoff curve corresponding to the subset of the T2 cutoff points, determining a free water level (FWL) of the reservoir based on the theoretical cutoff curve, and determining a rock type of the reservoir based on the theoretical cutoff curve.

Abstract: Methods are described for wettability characterization based on NMR measurements, which are sensitive to the surface wetting conditions of oil and water at the pore scale. The described methods make use of surface relaxation effects on the NMR relaxation (T2). Workflows are described to obtain wettability profiles of a porous media such as a rock either in the native state or prepared to a certain state in the laboratory. An underlying forward model is also described for the mixed wet and fractionally saturated pore spectrum. Outputs of the described inversion include continuous saturation and wettability profiles as a function of the pore sizes in the porous media, as well as an averaged value for saturation and wettability over the entire pore spectrum.

Abstract: Method and apparatus for estimating a kerogen (organic) porosity of an earth formation. The method may include using at least one processor to estimate a kerogen porosity using NMR signals indicative to an inorganic porosity and NMR signals indicative of a total porosity for a volume of interest in an earth formation. The apparatus may include an NMR tool configured to acquire NMR signals indicative to an inorganic porosity and NMR signals indicative of a total porosity for a volume of interest in an earth formation.

Abstract: A method for evaluating an earth formation from a well bore, that includes: collecting at least one of geochemical data, petrophysical data and geomechanical data from a wellbore; and identifying depositional facies of the earth surrounding the wellbore. A computer program product and a system are provided.

Abstract: Methods are described for wettability characterization based on NMR measurements, which are sensitive to the surface wetting conditions of oil and water at the pore scale. The described methods make use of surface relaxation effects on the NMR relaxation (T2). Workflows are described to obtain wettability profiles of a porous media such as a rock either in the native state or prepared to a certain state in the laboratory. An underlying forward model is also described for the mixed wet and fractionally saturated pore spectrum. Outputs of the described inversion include continuous saturation and wettability profiles as a function of the pore sizes in the porous media, as well as an averaged value for saturation and wettability over the entire pore spectrum.

Abstract: Method and apparatus for estimating a kerogen (organic) porosity of an earth formation. The method may include using at least one processor to estimate a kerogen porosity using NMR signals indicative to an inorganic porosity and NMR signals indicative of a total porosity for a volume of interest in an earth formation. The apparatus may include an NMR tool configured to acquire NMR signals indicative to an inorganic porosity and NMR signals indicative of a total porosity for a volume of interest in an earth formation.

Abstract: A method for estimating a property of a material, the method including: acquiring data using nuclear magnetic resonance (NMR) measurements, the measurements performed by varying at least one of a magnetic field gradient (G) and an inter-echo time (TE); organizing the data according to at least one of magnetic field gradients (G) and inter-echo times (TE) used in the NMR measurements; calculating a shift of apparent transverse relaxation time (T2,app) and (longitudinal relaxation time T1)/(apparent transverse relaxation time T2,app) due to a variation of the product of G and TE; constructing a mathematical model of the NMR measurements from the shifts; and inverting the mathematical model to estimate the property.

Abstract: A method for evaluating an earth formation from a well bore, that includes: collecting at least one of geochemical data, petrophysical data and geomechanical data from a wellbore; and identifying depositional facies of the earth surrounding the wellbore. A computer program product and a system are provided.

Abstract: A method for estimating a property of a material, the method including: acquiring data using nuclear magnetic resonance (NMR) measurements, the measurements performed by varying at least one of a magnetic field gradient (G) and an inter-echo time (TE); organizing the data according to at least one of magnetic field gradients (G) and inter-echo times (TE) used in the NMR measurements; calculating a shift of apparent transverse relaxation time (T2,app) and (longitudinal relaxation time T1)/(apparent transverse relaxation time T2,app) due to a variation of the product of G and TE; constructing a mathematical model of the NMR measurements from the shifts; and inverting the mathematical model to estimate the property.

Abstract: A method for determining viscosity, ?, of a fluid downhole, calls for performing a nuclear magnetic resonance (NMR) survey of the fluid; determining a longitudinal relaxation time, T1, and an apparent transverse relaxation time, T2app, for the fluid; forming a ratio R of T1/T2app for the fluid; and determining the viscosity, ?, according to the ratio, R. A computer program product for implementing the method is provided.

Abstract: A method for determining viscosity, ?, of a fluid downhole, calls for performing a nuclear magnetic resonance (NMR) survey of the fluid; determining a longitudinal relaxation time, T1, and an apparent transverse relaxation time, T2app, for the fluid; forming a ratio R of T1/T2app for the fluid; and determining the viscosity, ?, according to the ratio, R. A computer program product for implementing the method is provided.

Abstract: A method and apparatus for obtaining a parameter of interest relating to a region proximate a nuclear magnetic resonance (NMR) logging tool suitable for subterranean well logging is disclosed. The nuclei of the region are subjected to a pulsed NMR technique and are productive of NMR logging data, the nuclei of the region characteristically having a longitudinal relaxation time T1 distribution and an apparent transverse relaxation time T2app distribution. In response to the NMR logging data, an R distribution is defined as R=T1/T2app, the T2app and R distributions are processed as separate bins, along with the NMR logging data, according to a two-dimensional inversion model, and a signal intensity map of R versus T2app is provided that is representative of the parameter of interest relating to the region. In response to a high-intensity signal on the map being within a first range of T2app values and a first range of R values, the presence of a light hydrocarbon within the region is identified.