Date of download: 10/15/2017 Copyright © ASME. All rights reserved. Microfluidics Underground: A Micro-Core Method for Pore Scale Analysis of Supercritical CO2 Reactive Transport in Saline Aquifers J. Fluids Eng. 2013;135(2):021203-021203-7. doi:10.1115/1.4023644 Figure Legend: Schematic of the experimental setup for the micro-core flooding experiments with pure CO2 and CO2 saturated brine. The system uses a microfluidic chip style holder and connections which simplify the apparatus as compared to conventional core-study methods. The parts inside the dotted line were kept at constant temperature of 40 °C in a water bath. An image of the micro-core is shown inset.

Date of download: 10/15/2017 Copyright © ASME. All rights reserved. Microfluidics Underground: A Micro-Core Method for Pore Scale Analysis of Supercritical CO2 Reactive Transport in Saline Aquifers J. Fluids Eng. 2013;135(2):021203-021203-7. doi:10.1115/1.4023644 Figure Legend: SEM images of Indiana limestone core samples used in this study (a) intergranular pores; (b) intragranular pores of the dotted red line region in part (a). For both cases, the black areas are pores and gray areas are grains. Scale bars indicate 500 μm in (a) and 10 μm in (b).

Date of download: 10/15/2017 Copyright © ASME. All rights reserved. Microfluidics Underground: A Micro-Core Method for Pore Scale Analysis of Supercritical CO2 Reactive Transport in Saline Aquifers J. Fluids Eng. 2013;135(2):021203-021203-7. doi:10.1115/1.4023644 Figure Legend: Pore structure changes due to CO2-saturated brine injection for 3 h (a) before CO2 injection; (b) after CO2 injection; (c) binary image conversion from gray image and histogram. Coronal plane is the horizontal plane, sagittal plane is the vertical plane, and transaxial plane is the axial plane. The image resolution is 4.9 μm per pixel. Black areas are pores and gray areas are grains. The degree of dissolution is significant, with a porosity increase from 18.1% to 26.8% and an observable increase in pore connectivity.

Date of download: 10/15/2017 Copyright © ASME. All rights reserved. Microfluidics Underground: A Micro-Core Method for Pore Scale Analysis of Supercritical CO2 Reactive Transport in Saline Aquifers J. Fluids Eng. 2013;135(2):021203-021203-7. doi:10.1115/1.4023644 Figure Legend: Pore structure changes due to pure CO2 injection through the core for 3 h (a) before CO2 injection; (b) after CO2 injection. Coronal plane is the horizontal plane, sagittal plane is the vertical plane, and transaxial plane is the axial plane. The image resolution is 4.9 μm per pixel. Black areas are pores and gray areas are grain. In comparison with CO2-saturated brine flooding (Fig. 3), very little dissolution occurs in this case. Porosity increase is minor, from 17.5% to 19.5%.

Date of download: 10/15/2017 Copyright © ASME. All rights reserved. Microfluidics Underground: A Micro-Core Method for Pore Scale Analysis of Supercritical CO2 Reactive Transport in Saline Aquifers J. Fluids Eng. 2013;135(2):021203-021203-7. doi:10.1115/1.4023644 Figure Legend: Pressure drop across the core at each flow rate for permeability calculations before and after core flooding for 3 h at reservoir conditions of 8.4 MPa and 40 °C. (a) CO2-saturated brine core flooding. The linear fit of the flow rate versus pressure drop correlation R2 value is 0.999 for before and 0.996 for after core flooding. (b) ScCO2 core flooding. The linear fit of the flow rate versus pressure drop correlation R2 value is 0.993 for before and 0.966 for after core flooding.

Date of download: 10/15/2017 Copyright © ASME. All rights reserved. Microfluidics Underground: A Micro-Core Method for Pore Scale Analysis of Supercritical CO2 Reactive Transport in Saline Aquifers J. Fluids Eng. 2013;135(2):021203-021203-7. doi:10.1115/1.4023644 Figure Legend: Chemical analysis of the produced liquid showing both the Ca2+ and Mg2+ ion concentrations over time. (a) Ca2+ ion concentrations in the produced liquid measured with ICP-AES over the 3 h core flooding experiments with CO2-saturated brine and pure scCO2. (b) Mg2+ ion concentrations in the produced liquid measured with ICP-AES over the 3 h core flooding experiments with CO2-saturated brine and pure scCO2.