FRACTAL EVIDENCE OF REACTIVE TRANSPORT IN POROUS MEDIA UNDER ACID GAS INJECTION

Abstract

In the geologic and soil science literature, the fractal model of porous systems abound. Consequently, any process, be it physicochemical or geomechanical that impacts pore structure will equally impact the fractal nature of the system. Several studies have reported the effect of physicochemical processes such as water–rock interations, on the fractal dimension of the porous system using different approaches involving sophisticated instrumentation. Others have also reported the effect of geomechanical processes such as compaction on fractal dimension using similar approaches. To the best of our knowledge, none or little has been reported regarding the use of multiphase flow hydraulic models for revealing the effect of water–rock interactions on the fractal dimension and pore size distribution of porous systems under acid gas injection. Consequently, to fill the knowledeg gap, data on two-phase flow of acid gas and brine in porous media have been used to show that the fractal dimension and pore size distribution of the porous system change in response to water–rock interactions. The bases of the study are hydraulic models integrating the pore size distribution index parameter that have intimate associations with fractal dimension. Most importantly, the results of this study show that data on two-phase flow in porous media involoving acid gas and brine can be used to show changes in the fractal nature of the porous system, consistent with measurements made using sophisticated methods for core analysis.