Abstract: A device including a plurality of motors is disclosed. The device includes a body comprising a plurality of magnet arrays. Each magnet array comprises a plurality of magnets which define a polygon and the plurality of magnets are arranged in a semi-Halbach configuration. The polygons of the plurality of magnet arrays form a tessellating pattern in which the magnet arrays each share at least one magnet with another one of the magnet arrays. Each magnet is configured to be rotatable relative to the body, or in the case of coils as magnets, the input of each coil can be manipulated to replicate the same or similar effect. The device further comprises a plurality of rotors, wherein each magnet array is configured to receive a rotor rotatable relative to the body.

Abstract: Exemplary implementations may: obtain subsurface relaxation time data specifying subsurface relaxation time values corresponding to a well in the subsurface volume of interest; generating a subsurface relaxation time distribution using the subsurface relaxation time data; generating a subsurface porosity distribution using the subsurface relaxation time distribution; generating a representation of the subsurface porosity distribution in the subsurface volume of interest using visual effects to depict at least one of the one or more subsurface relaxation time values; and display the representation.

Abstract: A device including a plurality of motors is disclosed. The device includes a body comprising a plurality of magnet arrays. Each magnet array comprises a plurality of magnets which define a polygon and the plurality of magnets are arranged in a semi-Halbach configuration. The polygons of the plurality of magnet arrays form a tessellating pattern in which the magnet arrays each share at least one magnet with another one of the magnet arrays. Each magnet is configured to be rotatable relative to the body, or in the case of coils as magnets, the input of each coil can be manipulated to replicate the same or similar effect. The device further comprises a plurality of rotors, wherein each magnet array is configured to receive a rotor rotatable relative to the body.

Abstract: Exemplary implementations may: obtain subsurface relaxation time data specifying subsurface relaxation time values corresponding to a well in the subsurface volume of interest; generating a subsurface relaxation time distribution using the subsurface relaxation time data; generating a subsurface porosity distribution using the subsurface relaxation time distribution; generating a representation of the subsurface porosity distribution in the subsurface volume of interest using visual effects to depict at least one of the one or more subsurface relaxation time values; and display the representation.

Abstract: To measure the phase behavior of a fluid in a porous medium such as a tight gas shale, one illustrative method involves: (a) loading the fluid into a sample cell containing the porous medium; (b) setting a pressure and a temperature for the fluid in the sample cell; (c) applying an RF pulse sequence to the fluid in the sample cell to acquire an NMR signal; (d) deriving from the NMR signal an NMR parameter distribution that depends on the pressure and the temperature; (e) determining whether a fluid phase is present based on the NMR parameter distribution; (f) repeating operations (c) through (f) to determine the presence or absence of the fluid phase at multiple points along a pressure-temperature path that crosses a phase boundary; and (g) providing an estimated location of the phase boundary based on the presence or absence of the fluid phase at said points.

Abstract: A sensor and a method are disclosed for analyzing fluid and/or rock samples from a subsurface formation. Embodiments of the sensor and method utilize an array of magnets arranged in a specific way. The array and its arrangement may allow for NMR analysis of multiple samples or analysis of fluid samples which were not possible with existing technology. Further details and advantages of various embodiments of the method are described in more detail herein.

Abstract: An NMR sensor and method is disclosed for analyzing a core sample from a subsurface formation. Embodiments of the method utilize two or more magnets disposed proximate to each other. The configuration of the magnets allows for increased detection frequency, and creates a strong field with much finer resolution than existing designs. In addition, embodiments of the sensor may be used at the well site due to its small size and simple hardware. Further details and advantages of various embodiments of the method are described in more detail herein.

Abstract: A disclosed method for characterizing gas adsorption on a rock sample includes: measuring a nuclear magnetic resonance (NMR) response of the rock as a function of surrounding gas pressure along an isotherm; transforming the NMR response to obtain a Langmuir pressure distribution of gas adsorption on the rock sample; and displaying the Langmuir pressure distribution. The Langmuir pressure distribution may be shown in one dimension (e.g., contribution to signal response versus Langmuir pressure), or may be combined with additional pressure-dependencies such as spin-lattice relaxation time (T1), spin-spin relaxation time (T2), and chemical shift (?) to form a multi-dimensional distribution. The method can further include: identifying peaks in the Langmuir pressure distribution; and associating a gas storage mechanism and capacity with each peak.

Abstract: A method for determining the concentration of asphaltenes in a solution is described. A model is first established for estimating the concentration of asphaltenes in a solution based on multiple samples of solutions of asphaltenes in the solvent in which the concentrations are known. The multiple samples have varying concentrations of asphaltenes. The diffusivity and relaxation time are measured for each sample using two-dimensional NMR. The ratio of diffusivity to relaxation time for each sample is then calculated. A linear equation is determined to fit the relationship between the ratio of diffusivity to relaxation time and the asphaltene concentration by weight for the multiple samples, thus creating the model. For a given solution sample for which the concentration of asphaltenes is desired to be determined, diffusivity and relaxation time are determined using two-dimensional NMR, and the ratio of diffusivity to relaxation time is calculated.

Abstract: To measure the phase behavior of a fluid in a porous medium such as a tight gas shale, one illustrative method involves: (a) loading the fluid into a sample cell containing the porous medium; (b) setting a pressure and a temperature for the fluid in the sample cell; (c) applying an RF pulse sequence to the fluid in the sample cell to acquire an NMR signal; (d) deriving from the NMR signal an NMR parameter distribution that depends on the pressure and the temperature; (e) determining whether a fluid phase is present based on the NMR parameter distribution; (f) repeating operations (c) through (f) to determine the presence or absence of the fluid phase at multiple points along a pressure-temperature path that crosses a phase boundary; and (g) providing an estimated location of the phase boundary based on the presence or absence of the fluid phase at said points.

Abstract: An NMR sensor and method is disclosed for analyzing a core sample from a subsurface formation. Embodiments of the method utilize two or more magnets disposed proximate to each other. The configuration of the magnets allows for increased detection frequency, and creates a strong field with much finer resolution than existing designs. In addition, embodiments of the sensor may be used at the well site due to its small size and simple hardware. Further details and advantages of various embodiments of the method are described in more detail herein.

Abstract: A sensor and a method are disclosed for analyzing fluid and/or rock samples from a subsurface formation. Embodiments of the sensor and method utilize an array of magnets arranged in a specific way. The array and its arrangement may allow for NMR analysis of multiple samples or analysis of fluid samples which were not possible with existing technology. Further details and advantages of various embodiments of the method are described in more detail herein.

Abstract: A core sample holder assembly for performing a laboratory magnetic resonance measurement of a core sample taken from a hydrocarbon containing formation is provided. The assembly comprises a pressure chamber provided by a hull and one or more flanges are sealingly coupled with the hull. A flexible core sample holder sleeve is arranged within the pressure chamber and is sealingly coupled with at least one of the flanges. An overburden fluid injection port is in fluid communication with an annular space between the hull and the flexible sleeve and is configured to inject overburden fluid into an annular space between the hull and the flexible sleeve. A pressure regulator is configured to maintain the overburden fluid in the annular space at an elevated pressure. A radio-frequency antenna, within the pressure chamber and wrapped around the sample holder sleeve, is configured to receive an electromagnetic-signal from the core sample. In use, the core sample is arranged substantially within the sleeve.

Abstract: A disclosed method for characterizing gas adsorption on a rock sample includes: measuring a nuclear magnetic resonance (NMR) response of the rock as a function of surrounding gas pressure along an isotherm; transforming the NMR response to obtain a Langmuir pressure distribution of gas adsorption on the rock sample; and displaying the Langmuir pressure distribution. The Langmuir pressure distribution may be shown in one dimension (e.g., contribution to signal response versus Langmuir pressure), or may be combined with additional pressure-dependencies such as spin-lattice relaxation time (T1), spin-spin relaxation time (T2), and chemical shift (?) to form a multi-dimensional distribution. The method can further include: identifying peaks in the Langmuir pressure distribution; and associating a gas storage mechanism and capacity with each peak.

Abstract: A method for determining the concentration of asphaltenes in a solution is described. A model is first established for estimating the concentration of asphaltenes in a solution based on multiple samples of solutions of asphaltenes in the solvent in which the concentrations are known. The multiple samples have varying concentrations of asphaltenes. The diffusivity and relaxation time are measured for each sample using two-dimensional NMR. The ratio of diffusivity to relaxation time for each sample is then calculated. A linear equation is determined to fit the relationship between the ratio of diffusivity to relaxation time and the asphaltene concentration by weight for the multiple samples, thus creating the model. For a given solution sample for which the concentration of asphaltenes is desired to be determined, diffusivity and relaxation time are determined using two-dimensional NMR, and the ratio of diffusivity to relaxation time is calculated.

Abstract: Molecular structures of organic molecules in a geological formation are determined. The organic molecules may include kerogen, coal, and/or other organic molecules. In particular, the technique implemented may operate to convert nuclear magnetic resonance data into a multi-dimensional space that permits identification of molecular structures through comparisons of intensity information across the multi-dimensional space with a cutoff map of the space. This may not only simplify the identification of molecular structures of the organic molecules, but also use exact mathematical model for mixture samples to derive both structural and dynamic parameters plus their variation.

Abstract: A nuclear magnetic resonance relaxation time cutoff between results for a bound-water index of rock and a free-fluid index of the rock is determined. The determination is made based on measured and predicted values for permeability and/or wettability over a set of core plugs. The determination does not require a nuclear magnetic resonance operation performed on the core plugs under irreducible water saturation.

Abstract: A core sample holder assembly for performing a laboratory magnetic resonance measurement of a core sample taken from a hydrocarbon containing formation is provided. The assembly comprises a pressure chamber provided by a hull and one or more flanges are sealingly coupled with the hull. A flexible core sample holder sleeve is arranged within the pressure chamber and is sealingly coupled with at least one of the flanges. An overburden fluid injection port is in fluid communication with an annular space between the hull and the flexible sleeve and is configured to inject overburden fluid into an annular space between the hull and the flexible sleeve. A pressure regulator is configured to maintain the overburden fluid in the annular space at an elevated pressure. A radio-frequency antenna, within the pressure chamber and wrapped around the sample holder sleeve, is configured to receive an electromagnetic-signal from the core sample. In use, the core sample is arranged substantially within the sleeve.

Abstract: The present invention enables the use of a global optimization method for performing joint-inversion of multiple petrophysical data sets, using forward models based on first principle of physics, to generate a 3D rock representation of a subsurface rock structure. The resulting 3D rock representation captures the internal structure, and honors the measured petrophysical properties, of the subsurface rock structure. The 3D rock representation can then be used to predict additional properties not considered in the inversion, to further characterize the subsurface rock structure.

Abstract: A nuclear magnetic resonance relaxation time cutoff between results for a bound-water index of rock and a free-fluid index of the rock is determined. The determination is made based on measured and predicted values for permeability and/or wettability over a set of core plugs. The determination does not require a nuclear magnetic resonance operation performed on the core plugs under irreducible water saturation.