GSA Connects 2021 in Portland, Oregon

Paper No. 171-2
Presentation Time: 1:50 PM

EFFECTS OF RESERVOIR HYDROGEOLOGICAL HETEROGENEITY ON CO2 MIGRATION AND MINERAL TRAPPING: A CASE STUDY IN ILLINOIS BASIN, INDIANA


SHABANI, Babak, Indiana University, Indiana Geological and Water Survey, 1001 E. 10th Street, Bloomington, IN 47405 and ZHU, Chen, Department of Geological Sciences, Indiana University, 1001 E. 10th Street, Bloomington, IN 47405

The Cambrian Mount Simon sandstone of the Illinois Basin has been considered a site for potential geological CO2 storage (GCS) by the Midwest Geological Sequestration Consortium. The Mount Simon is overlain by the nearly impermeable shale of the Cambrian Eau-Clair Formation. In this study, three-dimensional (3D), high-resolution simulations facilitated by parallel computations assess the effect of hydrogeological heterogeneity on 1) CO2 plume evolution and storage and 2) geochemical reactions in a section of the Illinois Basin in southwestern Indiana.

Two scenarios were selected to investigate the effect of the reservoir porosity and permeability heterogeneity in 3D reactive transport simulations: 1) heterogenous case considering the porosity and permeability heterogeneity, named Base Case, and 2) homogenous case considering porosity and permeability homogeneity in the reservoir. The initial pressure, temperature, and mineralogical distributions are similar in both cases.

Results of the two cases indicate that hydrogeological heterogeneity significantly impacts carbon storage in 3D CO2 reservoir simulations of CO2 plume migration patterns, CO2-water-mineral interaction, reservoir quality, and storage safety and security.

  • CO2 plume developed a pillar-shaped profile reaching the top of the Mount Simon in the homogeneous case. However, it became mushroom-shaped and was restrained in the lower one-third of the formation when hydrogeologic heterogeneity was considered.
  • In the homogenous case, more porosity reduction near the injection well was observed, and porosity generation away from the injection well was negligible.
  • The dominant trapping mechanism in the heterogeneous case is mineral trapping (43%), while it is solubility trapping (47%) in the homogeneous case at the end of the simulation (10,000 yr). The study site is considered to be safer and securer for CO2 storage when the reservoir heterogeneity is considered.