Measurement and Analysis of CO2 Adsorption and Permeability in Shales in Application to Geological Carbon Storage

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides new experimental data and a modeling workflow for CO2 adsorption/permeability in shales, useful for reservoir simulation and storage capacity estimation.

🏢実務担当者:Offers a method to evaluate shale reservoirs for CO2 storage, aiding feasibility studies and site selection for CCUS projects.

🏛政策担当者:Supports evidence-based assessment of CCUS potential in shale formations, informing national decarbonization strategies and regulatory frameworks.

The rising carbon dioxide (CO2) emissions have intensified the urgency to develop effective strategies for decarbonization. One of the most promising solutions is carbon capture, usage, and storage (CCUS), especially underground storage in geological formations. This pathway allows the continued use of existing infrastructure/technologies while mitigating the impact of fossil fuel usage on global warming. Several options, such as the use of aquifers and depleted reservoirs, are possible; storing CO2 in depleted gas reservoirs, especially shale-gas reservoirs, offers a cost-effective and promising option for CCUS. Development of storage strategies requires a proper quantification of adsorption and transport characteristics of CO2 in these reservoirs, which are the main focus areas of this study. The proposed workflow incorporates both experimental and modeling approaches. The experimental component involves transient measurements of CO2 adsorption behavior in shale samples using a magnetic suspension balance (MSB). These measurements were conducted under reservoir conditions with temperatures ranging from 160°F (71°C) to 194°F (90°C) and pressures from 3,500 to 5,075 psi. The modeling approach uses the volume-averaging technique that Ratnakar and Dindoruk (2018, 2019) used to invert the transient data and evaluate CO2 permeability in the samples, while an accelerated experimental process was developed first without the existence of porous media (Ratnakar and Dindoruk 2015) and with further verification via experimentation by Ratnakar et al. (2019). More information and a general review of the role of diffusivity in oil and gas industries, including fundamentals, measurement, and correlative techniques, can be found in the study by Ratnakar and Dindoruk (2022). The results reveal that the pretreatment method plays a significant role in influencing adsorption behavior. In particular, shale samples subjected to high-temperature pretreatments, which were designed to remove residual volatile hydrocarbons, exhibited greater CO2 adsorption capacity. In addition, a notable finding was the plateau in adsorption observed at higher pressures, particularly as CO2 transitioned into its supercritical phase. This shift in adsorption dynamics highlights the changing interactions between CO2 and the shale matrix, which have critical implications for optimizing CO2 storage in deep geological formations. Furthermore, the CO2 permeability vs. pressure at a fixed temperature is aligned with the Klinkenberg effect at relatively lower pressures, as expected. The novelty of this work lies in the new data on CO2 adsorption and permeability in shale samples under reservoir conditions. Characterization of shales in this context has additional use cases even for sandstone reservoirs, as the shales will constitute the caprocks. These findings offer valuable insights for assessing and designing CO2 storage in subsurface environments, with significant implications for advancing CCUS implementation strategies.

• semanticscholar https://doi.org/10.2118/236585-pafirst seen 2026-08-09 05:42:19