Patent ID: 11965848
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method comprising:
preparing a brine having a resistivity Rw,
flushing, using an apparatus comprising a core holder and a conductivity meter, a core sample with the brine, wherein the core sample is disposed in the core holder;
determining, using the conductivity meter comprising a first electrode and a second electrode, a first true resistivity Rt1 at a first saturation Sw1 of the core sample, once a resistivity Rw of the brine going into the core sample is the same as a resistivity Rw of the brine going out of the core sample;
determining, using the conductivity meter, a function Rt=f(Sw) describing a dependency of a true resistivity Rt of the core sample and a saturation Sw in the core sample, based on an initial saturation Sw0, initial true resistivity Rt0, the first true resistivity Rt1, and the first saturation Sw1, a second true resistivity Rt2, and a first saturation Sw2;
determining, using the apparatus, a resistivity Ro of a fully saturated core sample by estimating a function Rt=f(Sw) to full saturation of the core sample at Sw=100%;
determining, using the apparatus, a resistivity index, I
    R
   
   =
   
    
     
      R
      t
     
     
      R
      o
     
    
    ⁢
       
    at
    ⁢
       
    the
    ⁢
       
    
     S
     
      w
      ⁢
      0
     
    
   
  
  ,
  
   S
   
    w
    ⁢
    1
   
  
  ,
  
   
    S
    
     w
     ⁢
     2
    
   
   ;
  
 

determining, using the apparatus, a saturation exponent n using linear regression of log-log plot of IR vs. Sw; and
determining, using the apparatus, one or more electrical properties of the core sample based on the saturation exponent.