Abstract: A coreflood experiment may be modeled by generating a three dimensional computer simulation model of a core plug and modeling within the three dimensional computer simulation model one or both of a fluid introduction element or a fluid extraction element of a core holder used in the coreflood experiment. Once generated, the model may be loaded and used when running a simulation to model a heterogeneous distribution of fluid flow proximate one or more faces of the core plug.

Abstract: Methods for improved interpretation of NMR data acquired from industrial samples by simultaneously detecting more than one resonant nucleus without removing the sample from the sensitive volume of the NMR magnet or radio frequency probe are disclosed. In other aspects, the present disclosure provides methods for robust imaging/analysis of spatial distribution of different fluids (e.g., 1H, 23Na, 19F) within a core or reservoir rock. NMR data may be interpreted in real-time during dynamic processes to enable rapid screening, e.g. of enhanced oil recovery techniques and products and/or to provide improved interpretation of well-logs. Measurements of resonant nuclei other than 1H may be performed in the laboratory or downhole with a NMR logging tool. In other aspects, the present disclosure describes a novel kernel function to extract values for underlying parameters that define relaxation time behavior of a quadrupolar nucleus.

Abstract: A coreflood experiment may be modeled by generating a three dimensional computer simulation model of a core plug and modeling within the three dimensional computer simulation model one or both of a fluid introduction element or a fluid extraction element of a core holder used in the coreflood experiment. Once generated, the model may be loaded and used when running a simulation to model a heterogeneous distribution of fluid flow proximate one or more faces of the core plug.

Abstract: A pressurizable holder for a sample to be examined by NMR, comprises a pressure retaining nonmagnetic tube surrounding a radio-frequency coil which in turn surrounds a space for the sample. The pressure retaining tube is formed of (i) nonmetallic electrically insulating material such as a ceramic or (ii) nonmetallic electrically insulating matrix material reinforced with electrically insulating filaments such as glass fiber, or (iii) non-metallic electrically insulating matrix material reinforced with electrically conductive filaments configured so that conductivity is anisotropic. There is good coil filling factor without constraint on wall thickness of the pressure retaining tube. Avoidance of isotropically conductive material inhibits eddy currents when an NMR spectrometer's magnetic field gradient coils are switched on and off. The tube resists hoop stress from internal pressure. Longitudinal stress is resisted by structure connecting end pieces at the ends of the pressure retaining tube.

Abstract: Methods for improved interpretation of NMR data acquired from industrial samples by simultaneously detecting more than one resonant nucleus without removing the sample from the sensitive volume of the NMR magnet or radio frequency probe are disclosed. In other aspects, the present disclosure provides methods for robust imaging/analysis of spatial distribution of different fluids (e.g., 1H, 23Na, 19F) within a core or reservoir rock. NMR data may be interpreted in real-time during dynamic processes to enable rapid screening, e.g. of enhanced oil recovery techniques and products and/or to provide improved interpretation of well-logs. Measurements of resonant nuclei other than 1H may be performed in the laboratory or downhole with a NMR logging tool. In other aspects, the present disclosure describes a novel kernel function to extract values for underlying parameters that define relaxation time behavior of a quadrupolar nucleus.

Abstract: A coreflood experiment may be modeled by generating a three dimensional computer simulation model of a core plug and modeling within the three dimensional computer simulation model one or both of a fluid introduction element or a fluid extraction element of a core holder used in the coreflood experiment. Once generated, the model may be loaded and used when running a simulation to model a heterogeneous distribution of fluid flow proximate one or more faces of the core plug.

Abstract: A method, apparatus, and program product may generate and/or utilize a three-dimensional computer simulation model of a core plug suitable for use in a computer-implemented general purpose reservoir simulator. Simulation studies may be performed on the simulation model to establish a water base case for the simulation model, and to establish one or more Enhanced Oil Recovery (EOR) chemical properties and further validate the simulation model.

Abstract: An apparent viscosity of an aqueous polymer composition used in a polymer flood may be determined by generating a relative permeability interpolation computer simulation model that is associated with a capillary desaturation function and that interpolates relative permeability curves for a coreflood experiment, validating the relative permeability interpolation computer simulation model using experimental data generated from the coreflood experiment using a water flood performed at a plurality of incremental flow rates on a core plug, determining an interpolated relative permeability to water for the aqueous polymer composition using experimental data generated from the coreflood experiment using a multi-phase flood with the aqueous polymer composition, and determining an apparent viscosity of the aqueous polymer composition from the interpolated relative permeability to water. The determined apparent viscosity may then be used to run a simulation to model the flow of the aqueous polymer composition.

Abstract: An apparatus and method for NMR analysis of a plurality of core samples includes a core holder (11) that holds a core sample under pressurized conditions. A radio frequency coil (51) disposed about the core holder (11) generates a pulsed-mode magnetic field component over a sample volume occupied by the core sample. A support structure is removably secured to the respective core holder. A permanent magnet (65A, 65B) has an open configuration such that it is removably disposed into a position within the support structure about the radio frequency coil and the core holder. The open configuration allows the same permanent magnet to be used for NMR analysis of a plurality of core samples without the need for depressurizing the respective core holder and disassembling the core holder and corresponding load frame for each core sample. It also allows multiple core samples to be prepared for NMR analysis while separated from the NMR measurement apparatus.

Abstract: Nuclear magnetic resonance apparatus for measuring properties of a fluid stream flowing within a pipeline has one or more magnet systems for applying magnetic field to the fluid stream and also has means for inducing and observing magnetic resonance within the fluid stream as it passes through a said magnetic field. The apparatus may also include a polarizing magnetic field upstream of the magnetic field in which resonance is observed. The fluid stream may be hydrocarbon from an underground reservoir. In order to guard against accumulation of magnetisable iron debris particles entrained in the fluid flow, the apparatus comprises one or more upstream traps having a magnetic field to attract and hold solid magnetizable material and an exit path for the removal of the solid magnetizable material so that it does not continue towards any polarizing field and the field where resonance is observed.

Abstract: A method of analyzing properties of a porous sample, typically a cylinder of porous rock, comprises centrifuging the sample while it contains at least one liquid, determining the distribution of at least one liquid in the sample by magnetic resonance imaging of the sample, and also determining the distribution of at least one magnetic resonance parameter, where the parameter is one of longitudinal relaxation time T1, transverse relaxation time T2 and diffusion coefficient D. Pore throat sizes can be determined from the distribution of at least one liquid in the sample and pore body sizes can be determined from the distribution of the magnetic resonance parameter enabling determination of a relationship between pore throat sizes and pore body sizes in the sample. This can be a relationship between individual values of pore throat size and an average of body sizes of pores having that individual pore throat size.

Abstract: An apparatus and method for NMR analysis of a plurality of core samples includes a core holder (11) that holds a core sample under pressurized conditions. A radio frequency coil (51) disposed about the core holder (11) generates a pulsed-mode magnetic field component over a sample volume occupied by the core sample. A support structure is removably secured to the respective core holder. A permanent magnet (65A, 65B) has an open configuration such that it is removably disposed into a position within the support structure about the radio frequency coil and the core holder. The open configuration allows the same permanent magnet to be used for NMR analysis of a plurality of core samples without the need for depressurizing the respective core holder and disassembling the core holder and corresponding load frame for each core sample. It also allows multiple core samples to be prepared for NMR analysis while separated from the NMR measurement apparatus.

Abstract: Nuclear magnetic resonance apparatus for measuring properties of a fluid stream flowing within a pipeline has one or more magnet systems for applying magnetic field to the fluid stream and also has means for inducing and observing magnetic resonance within the fluid stream as it passes through a said magnetic field. The apparatus may also include a polarizing magnetic field upstream of the magnetic field in which resonance is observed. The fluid stream may be hydrocarbon from an underground reservoir. In order to guard against accumulation of magnetisable iron debris particles entrained in the fluid flow, the apparatus comprises one or more upstream traps having a magnetic field to attract and hold solid magnetizable material and an exit path for the removal of the solid magnetizable material so that it does not continue towards any polarizing field and the field where resonance is observed.

Abstract: Nuclear magnetic resonance spectrometer for examination of a sample under pressure has a coolant vessel containing a radio-frequency coil cooled by coolant in the vessel while located within the magnetic field of the spectrometer. A pressurizable sample holder comprises a nonmagnetic pressure retaining tube formed of electrically insulating matrix material containing electrically insulating reinforcing filaments. The spectrometer is configured to accommodate this sample holder with the axis of the pressure retaining tube transverse to the magnetic field, and the radiofrequency coil at the exterior of the pressure retaining tube. Cooling of the coil improves the signal to noise ratio and offsets the low coil filling factor which is a consequence of placing the coil outside a non-metallic pressure retaining tube. End pieces at each end of the tube are connected together and contain longitudinal pressure stress.

Abstract: A laboratory NMR methodology (and corresponding laboratory apparatus) defines a sample volume. The method stores downhole tool data corresponding to a hydrocarbon-bearing sample collected from a given subsurface formation. The downhole tool data includes parameters pertaining to magnetic fields used by a downhole tool during a suite of NMR measurements of the given subsurface formation. The sample is positioned in the sample volume of the laboratory apparatus, which applies a static magnetic field in the sample volume. Furthermore, the laboratory apparatus applies a suite of NMR measurements to the sample volume to thereby determine a property of the sample. The NMR measurements of the suite each include a pulse sequence of oscillating magnetic field in conjunction with a pulsed-mode gradient field. The pulsed-mode gradient field is based on the stored downhole tool data corresponding to the sample. A laboratory NMR methodology for optimizing downhole NMR measurements is also described.

Abstract: A method of analysing properties of a porous sample, typically a cylinder of porous rock, comprises centrifuging the sample while it contains at least one liquid, determining the distribution of at least one liquid in the sample by magnetic resonance imaging of the sample, and also determining the distribution of at least one magnetic resonance parameter, where the parameter is one of longitudinal relaxation time T1, transverse relaxation time T2 and diffusion coefficient D. Pore throat sizes can be determined from the distribution of at least one liquid in the sample and pore body sizes can be determined from the distribution of the magnetic resonance parameter enabling determination of a relationship between pore throat sizes and pore body sizes in the sample. This can be a relationship between individual values of pore throat size and an average of body sizes of pores having that individual pore throat size.

Abstract: A pressurizable holder for a sample to be examined by NMR, comprises a pressure retaining nonmagnetic tube surrounding a radio-frequency coil which in turn surrounds a space for the sample. The pressure retaining tube is formed of (i) nonmetallic electrically insulating material such as a ceramic or (ii) nonmetallic electrically insulating matrix material reinforced with electrically insulating filaments such as glass fiber, or (iii) non-metallic electrically insulating matrix material reinforced with electrically conductive filaments configured so that conductivity is anisotropic. There is good coil filling factor without constraint on wall thickness of the pressure retaining tube. Avoidance of isotropically conductive material inhibits eddy currents when an NMR spectrometer's magnetic field gradient coils are switched on and off. The tube resists hoop stress from internal pressure. Longitudinal stress is resisted by structure connecting end pieces at the ends of the pressure retaining tube.

Abstract: A laboratory NMR methodology (and corresponding laboratory apparatus) defines a sample volume. The method stores downhole tool data corresponding to a hydrocarbon-bearing sample collected from a given subsurface formation. The downhole tool data includes parameters pertaining to magnetic fields used by a downhole tool during a suite of NMR measurements of the given subsurface formation. The sample is positioned in the sample volume of the laboratory apparatus, which applies a static magnetic field in the sample volume. Furthermore, the laboratory apparatus applies a suite of NMR measurements to the sample volume to thereby determine a property of the sample. The NMR measurements of the suite each include a pulse sequence of oscillating magnetic field in conjunction with a pulsed-mode gradient field. The pulsed-mode gradient field is based on the stored downhole tool data corresponding to the sample. A laboratory NMR methodology for optimizing downhole NMR measurements is also described.

Abstract: A laboratory NMR methodology (and corresponding laboratory apparatus) defines a sample volume. The method stores downhole tool data corresponding to a hydrocarbon-bearing sample collected from a given subsurface formation. The downhole tool data includes parameters pertaining to magnetic fields used by a downhole tool during a suite of NMR measurements of the given subsurface formation. The sample is positioned in the sample volume of the laboratory apparatus, which applies a static magnetic field in the sample volume. Furthermore, the laboratory apparatus applies a suite of NMR measurements to the sample volume to thereby determine a property of the sample. The NMR measurements of the suite each include a pulse sequence of oscillating magnetic field in conjunction with a pulsed-mode gradient field. The pulsed-mode gradient field is based on the stored downhole tool data corresponding to the sample. A laboratory NMR methodology for optimizing downhole NMR measurements is also described.

Abstract: Carbonate formations yield unreliable, down hole NMR results. Inter alia, these results must be corrected for temperature. The invention features several methods for obtaining more reliable NMR results for rock petrophysical parameters in carbonate rock formations based upon adjusting T.sub.2 data with respect to temperature.