Method and system for determining heterogeneous carbonate reservoir saturation exponent

A method for determining a saturation exponent of a heterogeneous carbonate rock reservoir, comprising:

• dividing a target reservoir into at least two reservoir types in accordance with a predetermined rule, which includes
• selecting a plurality of core samples of the target rock reservoir;
• and
• dividing the plurality of core samples into at least two core types to represent the at least two reservoir types in accordance with the predetermined rule;
• obtaining a correspondence relationship between a saturation exponent and a bound water saturation in each of the reservoir types, which includes
• obtaining the bound water saturation of each of the core samples;
• obtaining the saturation exponent of each of the core samples, which includes performing a rock electrical experiment to a number of the rock core samples in each of the reservoir types to acquire the saturation exponent;
• and
• linearly fitting the saturation exponent with the bound water saturation of the core samples that have gone through the rock electrical experiment in each of the reservoir types, so as to acquire the correspondence relationship between the saturation exponent and the bound water saturation in each of the reservoir types;
• the correspondence relationship being as follows
• n=aSwir+b,
• in which n is the saturation exponent, and Swir is the bound water saturation;
• determining the reservoir type to which a to-be-measured core belongs in accordance with the predetermined rule, wherein the to-be-measured core is the core sample that has not gone through the rock electrical experiment;
• obtaining a bound water saturation of the to-be-measured core;
• and
• calculating the saturation exponent of the to-be-measured core according to the bound water saturation of the to-be-measured core on the basis of the correspondence relationship of the reservoir type to which the to-be-measured core belongs.