Utica Shale Reactivity: CO2 Induced Pore Scale Changes in the Fracture Network and Matrix
Angela Goodman, Sean Sanguinito, Sittichai Natesakhawat, Patricia Cvetic, Barbara Kutchko, Andrew J. Allen
The Utica Shale is expected to be a substantial fossil fuel resource in the future. Currently, 663.5 billion cubic feet of natural gas and oil are being produced from the Utica in Eastern Ohio. In this work, we examined the Utica Shale and its reactivity with CO2 and water from the perspective of understanding the Utica Shale play as a storage reservoir for CO2, adapting CO2 as an enhanced hydrocarbon recovery agent, and investigating the sealing properties in the presence of CO2. Reactivity of Utica Shale was studied for outcrop and production samples at 40°C and CO2 pressures up to 10.3 MPa for 14 days. Pore characteristics and alterations were determined using N2 and CO2 sorption isotherms, mercury intrusion porosimetry, scanning electron microscopy, and X-ray scattering methods. This research shows that fluid is vital to chemical reaction between CO2 and shale as it can be present in the interstitial spaces in the clay layers or in the variable pore space of the matrix itself. During CO2 exposure, the presence of water can inhibit CO2 migration into the shale matrix, promote carbonate dissolution, and dramatically change the pore scale variability by opening and closing pore networks over the macro- to nano-scale range. The work discusses the importance of determining how and if pore alterations affect flow pathways, as ultimately flow property changes will affect hydrocarbon production, CO2 storage, and sealing units at the reservoir scale.
, Sanguinito, S.
, Natesakhawat, S.
, Cvetic, P.
, Kutchko, B.
and Allen, A.
Utica Shale Reactivity: CO2 Induced Pore Scale Changes in the Fracture Network and Matrix, Environmental Science & Technology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928666
(Accessed November 29, 2023)