Calculation of Klinkenberg Correction Coefficient and the Effect of Rock typing on its Results, Kangan and Dalan Formations in the Central Part of the Persian Gulf

Common methods for measuring permeability include well test data and core samples. In the laboratory, due to the low cost and high operating speed, the absolute gas permeability of plug samples is often measured. The permeability of the gas in the porous media depends on the average injection pressure and the type of used gas. It is obvious that by changing these parameters, different results are obtained. Therefore, it is necessary to measure the liquid permeability or determine the equivalent permeability of the liquid (Klinkenberg permeability). In this study, a total of 1245 porosity and permeability data were obtained from core analysis of Kangan and Dalan carbonate formations. The permeabilities of 111 samples were measured at 4 different pressures. The pressures were plotted versus permeabilities and the fluid equivalent permeability was calculated. Then, in this diagram, the slope of the fitted line was calculated for each sample, and the coefficient of variations was calculated for the slope of the samples in each rock type to find out the scatter of the samples. Results showed that determination of rock types by the used methods (Winland, flow zone indicator and Lorenz) has little effect on improving the results of this experiment (determination of the Klinkenberg coefficient). Among the methods used to determine the rock types, flow zone indicator parameters (porosity, permeability and matrix) have direct effects on the slope of the line (permeability-pressure regression line). This method also yields the highest coefficient of determination. It can also be concluded that it is not possible to obtain the equivalent liquid permeability of all samples using a constant correction factor. Comparison of the liquid permeability results with laboratory measured values shows that the method could be used for increasing the accuracy of the predicted permeabilities.