Abstract: Method and system for determining a confinement size in a porous media, including subjecting the media to a substantially uniform static magnetic field, applying a magnetic resonance pulse sequence to the media, detecting magnetic resonance signals from the media, determining non-ground eigenvalues from the magnetic resonance relaxation spectrum, and determining a confinement size of the media from the eigenvalues.

Abstract: A core holder for a reservoir rock core sample for MR or MRI measurement including a casing and a chamber internal to the core holder, an inlet and an outlet in the core holder for circulating a confining fluid in the chamber, a sample housing in the chamber for containing the core sample, the sample housing including an inlet and an outlet in the sample holder for circulating fluid to and from the sample, and a membrane for isolating the sample from fluid contact with the confining fluid but permitting fluid pressure to be exerted on the sample when the confining fluid is pressurized, the space in the chamber not occupied by the sample housing defining a void space, an RF probe in the void space and at least partially surrounding the sample housing, whereby confining fluid introduced into the chamber circulates in the void space around the RF probe.

Abstract: A method and system for generating a magnetic resonance pulse sequence for the investigation of a sample by magnetic resonance, including generating a selective scan comprising an adiabatic inversion magnetic resonance pulse sequence wherein the magnetization is inverted from z to ?z inside a frequency band, following the selective scan with a non-selective scan comprising a CPMG magnetic resonance pulse sequence wherein the magnetization is maintained along z, obtaining a first signal from the selective scan, obtaining a second signal from the non-selective scan, and subtracting the first and second signals to obtain a resulting signal with only selected frequency components for slice selective investigation of the sample.

Abstract: A magnet array is disclosed which is suitable for inter alia producing a remote field for use in unilateral magnetic resonance. In the “Magnet Array”, two separated magnets, which are magnetized along a substantially same collinear magnetization direction, produce a field with a local maximum centered above and between them. The field produced by the two separated magnets is substantially parallel to the collinear magnetization direction of the two separated magnets. A third magnet is centered between the two separated magnets. The third magnet has a magnetization direction which is substantially parallel to the collinear magnetization direction of the two separated magnets. The third magnet produces a field which is substantially parallel to the collinear magnetization direction of the two separated magnets, and adds to the increasing field below the local maximum point produced by the two separated magnets.

Abstract: A unilateral NMR sensor comprising a ferromagnetic yoke; a permanent magnet arranged on the yoke; a pole piece on the magnet; the pole piece including an air-pole piece interface surface whose shape corresponds to an equipotential contour of magnetic scalar potential. An approach for designing single-sided magnets suitable for unilateral magnetic resonance (UMR) measurements is presented. The method uses metal pole pieces to shape the field from permanent magnets in a target region. The pole pieces are shaped according to solutions to Laplace's equation, and can be designed using a combination of analytical methods and numerical optimization. The design leads to analytical expressions for the pole piece shape and magnetic field. The method is developed in Cartesian, polar, and spherical coordinates, and the merits of each system are discussed. The effects of finite magnet size on the field quality are explored through simulation, and are found to have a substantial effect in many cases.

Abstract: A unilateral NMR sensor comprising a ferromagnetic yoke; a permanent magnet arranged on the yoke; a pole piece on the magnet; the pole piece including an air-pole piece interface surface whose shape corresponds to an equipotential contour of magnetic scalar potential. An approach for designing single-sided magnets suitable for unilateral magnetic resonance (UMR) measurements is presented. The method uses metal pole pieces to shape the field from permanent magnets in a target region. The pole pieces are shaped according to solutions to Laplace's equation, and can be designed using a combination of analytical methods and numerical optimization. The design leads to analytical expressions for the pole piece shape and magnetic field. The method is developed in Cartesian, polar, and spherical coordinates, and the merits of each system are discussed. The effects of finite magnet size on the field quality are explored through simulation, and are found to have a substantial effect in many cases.

Abstract: A magnet array is disclosed which is suitable for inter alia producing a remote field for use in unilateral magnetic resonance. In the “Magnet Array”, two separated magnets, which are magnetized along a substantially same collinear magnetization direction, produce a field with a local maximum centered above and between them. The field produced by the two separated magnets is substantially parallel to the collinear magnetization direction of the two separated magnets. A third magnet is centered between the two separated magnets. The third magnet has a magnetization direction which is substantially parallel to the collinear magnetization direction of the two separated magnets. The third magnet produces a field which is substantially parallel to the collinear magnetization direction of the two separated magnets, and adds to the increasing field below the local maximum point produced by the two separated magnets.

Abstract: A probe suitable for use in unilateral nuclear magnetic resonance imaging and adapted to be embedded in a sample to be analysed, the probe comprising; a static magnetic field generator; a radiofrequency magnetic field generator adjacent to the static magnetic field generator; a circuit controlling the frequency response of the radiofrequency magnetic field generator, adjacent to the static magnetic field generator; an input cable coupled to the frequency control circuit and the frequency control circuit coupled to the radiofrequency magnetic field generator.

Abstract: Single-shot methods suitable for determining capillary pressure and relative permeability curves in petroleum reservoir core plugs are proposed. Three classes of measurement are outlined. (i) Measurements undertaken with steady state gas flow and stationary water or oil phases in the rock. SPRITE (Single-Point Ramped Imaging with T1 Enhancement) MRI (Magnetic Resonance Imaging) spin density images map spatially varying fluid content. (ii) Similar measurements are proposed with a stationary gas phase and flowing water or oil phases. (iii) Measurements are also possible with either water or oil as the stationary phase, with the other phase undergoing steady state flow. In all cases the outflow boundary condition is maintained, capillary pressure zero, by washing the outlet face of the sample with the stationary fluid phase.

Abstract: A probe suitable for use in unilateral nuclear magnetic resonance imaging and adapted to be embedded in a sample to be analysed, the probe comprising; a static magnetic field generator; a radiofrequency magnetic field generator adjacent to the static magnetic field generator; a circuit controlling the frequency response of the radiofrequency magnetic field generator, adjacent to the static magnetic field generator; an input cable coupled to the frequency control circuit and the frequency control circuit coupled to the radiofrequency magnetic field generator.

Abstract: Single-shot methods suitable for determining capillary pressure and relative permeability curves are proposed. For steady-state gas flow, with stationary water or oil remaining in a porous rock core and the outflow boundary condition (capillary pressure is zero) is maintained by washing the outlet face of the core with the stationary phase, the gas pressure distribution, P(x), is determined by SPRITE (Single-Point Ramped Imaging with T1 Enhancement) MRI (Magnetic Resonance Imaging) spin density imaging of flowing gas, since the spin density of gas is directly proportional to the pressure of the gas phase. Water or oil saturation distribution, S(x), at the present of steady-state flowing gas, is measured with MRI. The combination of P(x) and S(x) yields a capillary pressure curve, Pc(S) and relative permeability curve of flowing gas phase, Krg(S) can be determined with differential form of Darcy's law and ideal gas equations for gas flowing at steady-state.

Abstract: A unilateral NMR sensor comprising a ferromagnetic yoke; a permanent magnet arranged on the yoke; a pole piece on the magnet; the pole piece including an air-pole piece interface surface whose shape corresponds to an equipotential contour of magnetic scalar potential.