Measurement and correction of electrical parameters of incompletely saturated rock samples

Abstract The measurement of rock resistivity currently mainly adopts the method of reducing saturation, which requires the rock sample to reach complete saturation during measurement. In response to the accuracy issue of measuring rock electrical parameters using desaturation methods for unsaturated or incompletely saturated rock samples, the influence of saturation degree on the measurement results of rock electrical parameters and the root causes of the influence were analyzed, and a feasible correction method was established. The results indicate that the saturation degree of rock samples first affects the measurement of porosity, calculation of water saturation, and initial resistivity measurement of saturated saline rock samples, and further transmits to geological factors, cementation index, and lithology coefficient, while the saturation index is not affected by them. After correcting the porosity, water saturation, initial water saturation, and initial resistivity of the rock sample using saturation degree values, a one-to-one correspondence between water saturation and resistivity data was achieved. The base value for calculating the resistivity increase rate is more in line with reality, and the final rock electrical parameters obtained are more reasonable.