Patent ID: 11940437
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Measurement (Instruments)
Classification: CPC G  E | IPC E  G

Claim 9:
10. A computer-implemented method of analyzing a reservoir core sample tested under a laboratory multispeed centrifuge test of water displacing oil, the computer-implemented method comprising:
obtaining a set of average water saturation (Sw,avg) and imbibition capillary pressure (Pci) data points from a laboratory multispeed centrifuge test of a reservoir core sample;
applying, with a controller, a best-fit smoothing function to the data points to obtain a best-fit average saturation curve, wherein the best-fit average saturation curve represents imbibition capillary pressure (Pci) over average water saturation (Sw,avg);
converting, with the controller, the best-fit average saturation curve to an outlet-face saturation curve, wherein the outlet-face saturation curve represents imbibition capillary pressure (Pci) over outlet water saturation (Sw,outlet);
applying, with the controller, a best-fit straight line to the outlet-face saturation curve associated with a substantially constant outlet water saturation and changing imbibition capillary pressure;
determining, with the controller, a waterflood residual oil saturation (Sorw) of the core sample, the waterflood residual oil saturation associated with a point on the outlet-face saturation curve where the best-fit straight line deviates from the outlet-face saturation curve, wherein the waterflood residual oil saturation (Sorw) represents the ratio of the volume of the oil trapped in pores of the reservoir core sample under waterflooding to the total volume of the pores of the reservoir core sample; and
providing the waterflood residual oil saturation (Sorw).