Calcite-functionalized microfluidic chip for pore scale investigation of biogeochemical interactions in porous media

Micromodels are widely used to simulate subsurface reservoir environments for investigating multiphase flow and interactions within porous media. However, existing models often fail to accurately replicate the geochemical characteristics of reservoir minerals due to material limitations. This study presents a method for fabricating calcite-functionalized micromodels, wherein calcite crystals are grown <i>in situ</i> through microbial-induced carbonate precipitation (MICP). The technique enables precise, site-selective calcite growth, offering control over the morphology of CaCO₃ precipitates, as well as the geometry and porosity of the micromodels. The resulting calcite-functionalized micromodels more accurately mimic the mineralogical and physical properties of natural carbonate reservoirs. Utilizing these micromodels, we achieved real-time visualization of geochemical and biogeochemical processes within porous media, facilitating detailed examination of pore-scale microbial-fluid-rock interactions pertinent to gas storage applications.