CHARACTERIZATION OF THE MT. SIMON FORMATION TO DETERMINE SUITABILITY FOR CO2 SEQUESTRATION

CO₂ sequestration in deep subsurface environments has been proposed as an innovative strategy to lessen the impact of burning fossil fuels on Earth’s atmosphere. In order for CO₂ sequestration to be effective, the target formation must have sufficient porosity, permeability, depth and thickness to store CO₂. The Mt. Simon formation, a Cambrian arenite to subarkosic sandstone in western Ohio may provide appropriate physical and mineralogical properties for effective CO₂ sequestration. The goal of this research is to measure the Mt. Simon’s porosity and permeability, as well as to determine mineralogy of detrital grains and cementation to assess the formation’s suitability for CO₂ sequestration.

Porosity measurements are determined using mercury porosimetry, gas sorption, and scanning electron microscopy (SEM) to determine pore space and pore size distribution. Preliminary results show a range of 5-15% pore space present. Permeability was measured with a probe permeameter. Initial results range from ~ 0.1 -50.0 mD. Variations in porosity and permeability show that the formation is very heterogeneous, changing substantially on a centimeter scale.

Mineralogical characterization of the Mt. Simon using powder X-ray diffraction, SEM, and polarized light microscopy shows lithologic variation from arenite to feldspathic sandstone, with cementation that includes quartz, illite, iron and titanium oxides, and iron sulfides. Some samples in the formation contain severely deformed and fractured grains with quartz overgrowths. Comparisons of mineralogy and porosity measurements show porosity increases with increasing extent of hematite cement. Further results will be interpreted in conjunction with mineralogy, porosity, and permeability data from additional Mt. Simon samples from wells across western Ohio, to create a stratigraphic analysis of the Mt. Simon formation in this region.

This research is being carried out at the new Subsurface Energy Materials Characterization and Analysis Lab (SEMCAL) in the school of Earth Sciences at The Ohio State University.