Executive Summary : | The research aims to understand the impact of individual lithotype properties on seam-scale sorption, permeability, fracture toughness, and geomechanical attributes. The study reveals that gas content, transmissivity, and production ability are influenced by pore size distribution, textural and thermal maturity, organic and inorganic content, and fracture attributes of constituent lithotypes. These properties are also influenced by deposition, diagenesis, and post-diagenetic processes, resulting in strong heterogeneity in seam-scale behavior. A multi-pronged approach is proposed, including pore characterization, sorption behavior analysis, permeability analysis, X-ray micro-CT visualization, and fracture toughness assessment. Pore size and morphology characterization will be performed using Mercury Intrusion Porosimetry, low-pressure N₂ and CO₂ adsorption, and X-ray micro-CT imaging. X-ray Diffraction spectroscopy will be used to identify and quantify mineral matter associated with the lithotypes. Coal composition will be determined through proximate and ultimate analysis, scanning electron microscopy and reflected-light microscopy will be used to identify organic and inorganic constituents, and high-pressure CH₄/CO₂ adsorption and permeability analysis will quantify the sorption potential and gas flow behavior of individual lithotypes. The study will also examine strength and fracture behavior using uniaxial and triaxial loading and fracture toughness analysis of individual lithotypes. The correlation of sorption and flow behavior with organic and inorganic composition, pore structure, and fracture characteristics will provide a deeper understanding of lithotype control on gas sorption and permeability. |