EXPERIMENTAL DETERMINATION OF ABSOLUTE AND RELATIVE PERMEABILITY IN COMPOSITE CORES: EFFECT OF ORDERING

Experimental studies and in particular core flood tests are key elements in understanding the fluid flow in porous media. To minimize capillary end effect and obtain adequate data, it is strongly suggest that core flood experiments be performed using longer core samples or composite cores. Although a number of researchers have studied different fluid flow characteristics in composite cores, more studies are still necessary to fill the knowledge gaps, particularly in areas such as the effects of individual core ordering on absolute and relative permeability values of composite cores. The aim of this study was to find the best arrangement in the composite core system, and therefore a generalized criterion, by comparing absolute and relative permeability data to the average of individual core samples. Unsteady-state, two-phase core flood tests were conducted using three different individual core samples and different arrangements of individuals in composite core, i.e., ascending, descending, and the Huppler's arrangement. Analysis of the results revealed that for both absolute and relative permeability, descending arrangement leads to the most accurate values when compared with the average absolute and relative permeability values of individual core samples. In addition, it is realized that descending arrangement gives a higher recovery factor than the other two arrangements. According to the results of this study, it is greatly recommended to stack the individual core samples in descending order to minimize the errors in experimental determination of absolute and relative permeability.