An NMR apparatus includes a depressurizing device for depressurizing an NMR probe, a gas supply device for supplying gas into the NMR probe to thereby pressurize the NMR probe, and a control device. The control device alternately repeats depressurization of the NMR probe, using the depressurizing device, and pressurization of the NMR probe, using the gas supply device. This replaces the gas in the NMR probe.

The present invention provides a device and a method for measuring fluid saturation in nuclear magnetic resonance (NMR) on-line displacement, the method comprising: measuring a nuclear magnetic resonance (NMR) T2 spectrum under the dead volume filling of the on-line displacement system as displacing phase fluid and the core to be measured as saturated nuclear magnetic detection phase fluid to generate a calibrated T2 spectrum; measuring a nuclear magnetic resonance (NMR) T2 spectrum of a process in which the core to be measured is converted from a saturated displaced phase fluid into a displacing phase fluid to generate a displacement process T2 spectrum; generating the fluid saturation of the on-line displacement system in real time according to the generated calibrated T2 spectrum and the displacement process T2 spectrum. The present invention achieves the purpose of improving measurement precision of fluid saturation in the on-line displacement process.

A method of enhancing the nuclear spin polarization of target molecules (10) uses a hyperpolarized source material (12) that is co-confined with the target molecules (10) in a porous molecular matrix (20). The matrix (20) may be a D4R-polysiloxane copolymer such as polyoligosiloxysilicone number two (PSS-2) that has recesses of an appropriate diameter. A source material (12), such as parahydrogen, is transferred to the matrix (20) together with the target molecules (10), and an external pressure is applied to force them into the recesses of the matrix (20). The nano-confinement of the source material (12) and target molecules (10) together enables or enhances a transfer of spin polarization from the source material (12) to the target molecules (10). When the target molecules (10) are removed from the matrix (20), the enhanced spin polarization greatly enhances the signal strength of the target molecules (10) in any subsequent magnetic resonance measurement.

Methods for determining a volume of stored gas within a rock sample includes loading a rock sample into an overburden cell. A hydrocarbon gas at a gas pressure is applied to the rock sample and a confining fluid at a confining pressure is applied to the overburden cell. The confining pressure and the gas pressure are increased until a first pressure and temperature condition is met. With the rock sample maintained at the first temperature and pressure condition, a nuclear magnetic resonance spectrometer is used to scan the rock sample and measure a hydrocarbon gas volume within the rock sample. This measured hydrocarbon gas volume is then corrected using a Real Gas Index to determine the volume of stored gas within the rock sample.

A sample chamber holder for MAS-NMR capable of operating at both low and high pressures. In one example the sample chamber holder is made up of a sample holder body defining a sample chamber therein, a connector configured to operatively statically hold an in situ rotor within the sample chamber; a coupler configured to operatively connect the sampler holder body to a magnetically coupled rotation member. The magnetically coupled rotation member is configured to engage and rotate a sealing cap from an NMR rotor in such a way so as to allow an NMR cap to be alternatively opened or sealed in-situ while the NMR rotor remains statically positioned in an NMR device.

Methods for determining a volume of stored gas within a rock sample includes loading a rock sample into an overburden cell. A hydrocarbon gas at a gas pressure is applied to the rock sample and a confining fluid at a confining pressure is applied to the overburden cell. The confining pressure and the gas pressure are increased until a first pressure and temperature condition is met. With the rock sample maintained at the first temperature and pressure condition, a nuclear magnetic resonance spectrometer is used to scan the rock sample and measure a hydrocarbon gas volume within the rock sample. This measured hydrocarbon gas volume is then corrected using a Real Gas Index to determine the volume of stored gas within the rock sample.

A high-pressure magic angle spinning (MAS) rotor is detailed that includes a high-pressure sample cell that maintains high pressures exceeding 150 bar. The sample cell design minimizes pressure losses due to penetration over an extended period of time.

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.

Pressure coring where the core apparatus drills the core sample and seals the core sample at its native downhole pressure (e.g., several thousand psi) may be expanded to include nuclear magnetic resonance (NMR) imaging components to produce a pressurized NMR core holder that allows for NMR imaging of the core samples having been maintained in a downhole fluid saturation state. NMR imaging performed may include 1H and also 19F imaging depending on the chamber fluid used in the pressurized NMR core holder.

Preparations of a highly coherent diamond nitrogen vacancy (NV.sup.−) and a diamond anvil are provided. A graphite is used as a carbon source, a diamond is used as a crystal seed, aluminum/titanium is used as a nitrogen remover, and a single crystal diamond is synthesized under a high temperature and a high pressure, and high-pressure-high-temperature (HPHT) annealing is performed on the synthesized diamond; after the annealing, multiple NV.sup.−s are generated in <100> and <311> crystal orientation growth regions from scratch, while native NV.sup.−s in a <111> crystal orientation growth region are disappeared; and the <100> and <311> crystal orientation growth regions do not contain defects related to ferromagnetic elements. The high-density and highly coherent NV.sup.−s are produced under nondestructive conditions, and the diamond anvil with controlled NV.sup.− depths are prepared to achieve a precise detection of the NV.sup.− at a pressure above 60 GPa.