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US 11,898,976 B2Granted
Advanced NMR analysis of pore type and pore connectivity in core samples including diffusional fluid exchange methods
AssigneeExxonMobil Technology and Engineering Company
InventorsPavel Kortunov, Hubert E. King, Harry W. Deckman
Life of this patent
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Abstract
A method for determining the pore types of a core sample can include: determining a porosity of a core sample, wherein the core sample has a permeability of 10 mD or less; saturating the core sample with a NMR saturation fluid to achieve a saturated core sample; taking a NMR measurement of fluids in the saturated core sample; and deriving a volume for a pore type based on the porosity based on a correlation between the NMR measurement and a NMR signal to fluid volume calibration, wherein the pore type is selected from the group consisting of a nanopore, a micropore, a macropore, and any combination thereof.
Claims21
A method comprising:
- determining a porosity of a core sample, wherein the core sample has a permeability of 10 milliDarcy (mD) or less;
- saturating the core sample with a nuclear magnetic resonance (NMR) saturation fluid to achieve a saturated core sample;
- taking a first NMR measurement of fluids in the saturated core sample;
- hydraulically exchanging a fluid in the saturated core sample with a NMR exchange fluid;
- taking a second NMR measurement of the saturated core sample after hydraulic exchange;
- and
- deriving a volume for pore types based on a correlation between the first NMR measurement, the second NMR measurement and a NMR signal to fluid volume calibration, wherein the volume for pore types identifies an amount of water disposed in nanopores of the saturated core sample relative to macropores of the saturated core sample;
- and
- developing a production plan based on the amount of water disposed in nanopores of the saturated core sample relative to macropores of the saturated core sample.
6 more elements
A method comprising:
- determining a porosity of a core sample, wherein the core sample has a permeability of 10 milliDarcy (mD) or less;
- taking a first nuclear magnetic resonance (NMR) measurement of fluid in the core sample that is saturated;
- diffusionally exchanging a first fluid in the saturated core sample in a NMR exchange fluid, wherein the first fluid is a hydrophobic fluid and the NMR exchange fluid is a hydrophobic NMR exchange fluid;
- taking a first plurality of NMR measurements overtime of the fluid in the saturated core sample during diffusional exchange with the first NMR exchange fluid;
- analyzing a pore connectivity based on the porosity, a NMR signal to fluid volume calibration, and a comparison between the first NMR measurement and the first plurality of NMR measurements, wherein when using the hydrophobic NMR exchange fluid the pore connectivity analysis includes pore types selected from the group consisting of a nanopore oil volume, a micropore oil volume, a macropore oil volume, and any combination thereof;
- diffusionally exchanging a hydrophilic fluid in the saturated core sample in a hydrophilic NMR exchange fluid;
- taking a second plurality of NMR measurements of the fluid in the saturated core sample during diffusional exchange with the hydrophilic NMR exchange fluid;
- and
- deriving the pore connectivity analysis that further includes pore types selected from the group consisting of a nanopore water volume, a micropore water volume, a macropore water volume, and any combination thereof based on the porosity and a comparison between at least one of the first plurality of NMR measurements and the second plurality of NMR measurements.
6 more elements
A method comprising:
- determining a porosity of a core sample, wherein the core sample has a permeability of 100 milliDarcy (mD) or less;
- saturating the core sample with a NMR saturation fluid to achieve a saturated core sample;
- taking a first NMR measurement of the fluid in the saturated core sample;
- diffusionally exchanging a first fluid in the saturated core sample in a NMR exchange fluid, wherein the first fluid is a hydrophobic fluid and the NMR exchange fluid is a hydrophobic NMR exchange fluid;
- taking a second NMR measurement of the fluid in the saturated core sample after diffusional exchange;
- deriving a property of the saturated core sample based on the porosity, a NMR signal to fluid volume calibration, and a comparison between the first NMR measurement and the second NMR measurement, wherein when using the hydrophobic NMR exchange fluid the property is selected from the group consisting of a mobile nanopore oil volume, an immobile nanopore oil volume, a mobile micropore oil volume, an immobile micropore oil volume, a mobile macropore oil volume, an immobile macropore oil volume, and any combination thereof;
- diffusionally exchanging a hydrophilic fluid in the saturated core sample in a hydrophilic NMR exchange fluid;
- taking a third NMR measurement of the fluid in the saturated core sample during diffusional exchange with the hydrophilic NMR exchange fluid;
- and
- deriving a further property selected from the group consisting of the mobile nanopore water volume, the immobile nanopore water volume, the mobile micropore water volume, the immobile micropore water volume, the mobile macropore water volume, the immobile macropore water volume, and any combination thereof based on the porosity, the NMR signal to fluid volume calibration, and a comparison between the second NMR measurements and the third NMR measurement.
7 more elements
Dependencies are inferred from the claim text.