M.K. Rahmareza, Fatkhan, M.R. Setiawan
Understanding rock mineral composition is crucial for assessing mechanical behavior under stress. Traditional segmentation methods typically distinguish only between matrix and pore spaces. This study employs k-means clustering to identify pore spaces and three mineral components, which are then used for brittleness index analysis through a digital rock physics approach. Segmentation results show that the sedimentary sample consists of 11% porosity, 11% quartz, 31% calcite, and 47% ankerite, while the metamorphic sample contains 3% porosity, 8% calcite, 18% magnetite, 34% pyrrhotite, and 37% quartz. Brittleness index calculations, based on an elasticity-based approach, range from 228.2-332.5 for the sedimentary sample and 333.4-626.3 for the metamorphic sample. Brittleness is linked to stress response, where lower porosity increases resistance to deformation, making the rock more brittle. Additionally, quartz, a strong mineral, enhances brittleness at higher concentrations. Based on brittleness index values and mineral composition, the metamorphic sample, with lower porosity and higher quartz content, exhibits greater brittleness than the sedimentary sample. © Published under licence by IOP Publishing Ltd.
Department of Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, 40132, Indonesia; Physics Departement, Institut Teknologi Sumatera, Lampung, South Lampung, 35365, Indonesia