Changes in Pore Geometry and Connectivity in the Basalt Pore Network Adjacent to Fractures in Response to CO2-Saturated Fluid

Abstract

Pores connected to fractures provide an increased surface area for fluid-rock interactions when reactive fluids, such as CO2-saturated water, flow within fractures. Diffusion-controlled transport of ions including dissolved CO2, Ca2+, Mg2+, Fe2+, and Si within the connected pore network can lead to local mineral undersaturation or supersaturation and respective local dissolution or precipitation of secondary minerals. In this study, a diffusion-controlled experiment was conducted on a fractured basalt under subsurface conditions (60°C and 80 bars) to investigate the changes in the pore volume, the connectivity within the pore network, the pore and throat size distribution and to quantify the..