Experimental study of the impact of CO2 injection on the pore structure of coal: A case study from the Bowen Basin, Australia

• DOI: 10.1016/j.coal.2023.104314
• Publication Date: 2023-07-22T23:18:23Z
• Authors: Alireza Salmachi; Abbas Zeinijahromi; Mohammed Said Alg...; Nawaf Abdullah Ab...; Saad Abdullah Alq...; Alexander Badalyan; Mohammad Rezaee; Mojtaba Rajabi
• Keywords: Siltstone

This study investigates the impact of carbon dioxide (CO2) on pore structure coal during CO2 injection to understand technical challenges associated with sequestration in depleted seam gas reservoirs. In an integrated approach, Micro-Computed Tomography (micro-CT) scanning, helium porosity and air permeability tests are performed a sample prior after flooding experiments identify both reversible irreversible changes cleat fracture networks. The results indicate that contribute 43% reduction effective porosity, which can be readily observed 3D model networks constructed flooding. At lower stresses, compressibility offsets matrix swelling effect, resulting improved permeability, is beneficial for injection. Additionally, analysis borehole image logs well reveals most fractures cleats terminate within intervals, very few extending into adjacent strata siltstone fine sandstone low permeability.