Nuclear magnetic resonance (NMR) gas isotherm techniques to evaluate wettability of porous media, such as hydrocarbon reservoir rock, can include constructing a NMR gas isotherm curve for a porous media sample gas adsorption under various pressures. A hydrophobic or hydrophilic nature of the porous media sample can be determined using the NMR gas isotherm curves. A wettability of the porous media sample can be determined based on the NMR gas isotherm curve. The wettability can be determined for porous media samples with different pore sizes. In the case of reservoir rock samples, the determined wettability can be used, among other things, to model the hydrocarbon reservoir that includes such rock samples, to simulate fluid flow through such reservoirs, or to model enhanced hydrocarbon recovery from such reservoirs.

Nuclear magnetic resonance (NMR) gas isotherm techniques to evaluate wettability of porous media, such as hydrocarbon reservoir rock, can include constructing a NMR gas isotherm curve for a porous media sample gas adsorption under various pressures. A hydrophobic or hydrophilic nature of the porous media sample can be determined using the NMR gas isotherm curves. A wettability of the porous media sample can be determined based on the NMR gas isotherm curve. The wettability can be determined for porous media samples with different pore sizes. In the case of reservoir rock samples, the determined wettability can be used, among other things, to model the hydrocarbon reservoir that includes such rock samples, to simulate fluid flow through such reservoirs, or to model enhanced hydrocarbon recovery from such reservoirs.

A method for monitoring the oleophilic fluid to aqueous fluid ratio of a drilling fluid includes selecting a sample of the drilling fluid that has been recirculated, measuring the NMR response of the sample of the drilling fluid and determining the oleophilic fluid to aqueous fluid ratio of the drilling fluid based at least in part on the NMR response.

A subterranean characterization and fluid sampling device for analyzing a fluid from a subterranean formation includes a controller, a tool body, and a probing module. The tool body includes a fluid testing module configured to receive a sample of the fluid from the subterranean formation and a permanent magnet configured to induce a static magnetic field (B0). The probing module is coupled to the tool body and separate from the permanent magnet, and configured to withdraw the fluid from the formation and deliver the fluid to the testing module. The probing module comprises an antenna that generates a radio frequency magnetic field (B1) in response to a signal from the controller.

A method for determining the degree of cure in forages using a nuclear magnetic resonance (NMR) technique. An NMR instrument is used to determine the amount of bound moisture (typically called stem moisture) and free moisture (typically called dew moisture) the degree of which can be used to determine how cured the forage is. This method represents an improvement on the traditional ways of determining how cured a forage is. The traditional ways have been by twisting a bunch of forage in ones hands or using a mechanical method (Hammer of fingernail) to determine if there is too much stem moisture in the stem nodes. The method can be applied using a portable instrument or building the instrument into a forage harvesting machine such as a hay baler.

A method for partitioning NMR T.sub.1-T.sub.2 data may comprise: identifying modes in NMR T.sub.1-T.sub.2 data from a plurality of samples with a multimodal deconvolution or decomposition with regularized nonlinear inversion; deriving a modal properties vector comprising modal properties for each of the modes; performing a cluster analysis of the modes to identify clusters; assigning a poro-fluid class to the clusters based on one or more of the modal properties of the modes in each of the clusters; and deriving partitioned representations for the clusters based on the cluster analysis.

A method for deriving at least one pore or fluid relaxation parameter and endpoint selected from the group consisting of a longitudinal T.sub.1 pore surface relaxivity constant (ρ.sub.1), a transverse T.sub.2 pore surface relaxivity constant (ρ.sub.2), a pore surface-to-volume ratio (A/V), an equivalent pore-throat radius (r.sub.eq), and a bulk fluid relaxation time (T.sub.B) comprising: identifying modes in NMR T.sub.1-T.sub.2 data; assigning the modes to a poro-fluid class; clustering the modes based on poro-fluid class; estimating T.sub.B based on an asymptote fit of the clusters using T.sub.1 and T.sub.2 relaxation mechanisms in a bulk fluid relaxation-dominated limit; estimating ρ.sub.2/ρ.sub.1 based on an asymptote fit of the clusters using T.sub.1 and T.sub.2 relaxation mechanisms in a surface relaxation-dominated limit; fitting the T.sub.1 and T.sub.2 relaxation mechanisms to the clusters using the estimated T.sub.B; and deriving the pore or fluid relaxation parameter and endpoint for the poro-fluid classes from the fit.

A method for partitioning NMR T.sub.1-T.sub.2 data may comprise: identifying modes in NMR T.sub.1-T.sub.2 data from a plurality of samples with a multimodal deconvolution or decomposition with regularized nonlinear inversion; deriving a modal properties vector comprising modal properties for each of the modes; performing a cluster analysis of the modes to identify clusters; assigning a poro-fluid class to the clusters based on one or more of the modal properties of the modes in each of the clusters; and deriving partitioned representations for the clusters based on the cluster analysis.

A method of using the transverse relaxation rate (R.sub.2) of solvent NMR signal to detect filling errors of an alum-containing product in real-time in-line during manufacturing, for example during a fill-finish unit operation. This technique can be used for quality control in vaccine manufacturing to ensure the delivery of the correct concentration of alum-containing product to the product container such as a vial or pre-filled syringe.

A method and an apparatus for measuring oil content of a tight reservoir based on nuclear magnetic resonance includes applying a pulse sequence to a tight reservoir rock, and after applying a first pulse and a last pulse in the pulse sequence, applying a gradient magnetic field to the tight reservoir rock, respectively, directions of the two applied gradient magnetic fields being opposite to each other, wherein the pulse sequence is composed of three 90 pulses; acquiring a nuclear magnetic resonance signal of the tight reservoir rock; and determining oil content of the tight reservoir rock according to an intensity of the nuclear magnetic resonance signal. The method can accurately distinguish an oil phase nuclear magnetic resonance signal and a water phase nuclear magnetic resonance signal in nanopores of tight reservoir rock, thereby effectively improving the accuracy of the detection result of the oil content of the tight reservoir rock.