Patent ID: 11898976
Assignee: EXXONMOBIL TECHNOLOGY AND ENGINEERING COMPANY
Field: Measurement (Instruments)
Classification: CPC G  Y | IPC G

Claim 15:
16. 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.