Publications

This study on the Balikpapan Formation, Miocene age coals in the Sangatta II CBM PSC determined cleat orientation and relationships between cleat spacing, aperture, and cleat height, in order to build a 3D model of cleat density, volume and permeability. Methods used in this study include fieldwork, quantitative analysis, and laboratory analysis including proximate and maceral, and 3D fracture modelling by the use of a Hybrid Model Face cleat orientation measured at outcrops is E-W in the Bengalon area, NNW-SSE in the North Pinang area, and NE-SW in the South Pinang area. Face cleats with a NNW-SSE orientation were interpreted as the result of superimposed endogenic processes associated with coalification. Face cleats with N-E and NE-SW orientations are mainly associated with local tectonic stresses. Quantitative cleat and fracture data from this study indicate that a power-law distribution exists between density with spacing, and between cumulative fractures and spacing and aperture, with a r-squared fit of 0.90. Coal rank affected cleat density and cleat attributes. Cleat density for individual seams varies from 0.17 cm/cm2 to 0.51 cm/cm2. Density increases toward the Pinang Dome, related to structural position. Micro-cleat apertures range from 0.8μm – 15 μm and increase towards local stress areas to 15 μm - 30 μm. Permeability from outcrop samples was high at 50 md to 5000 md. Permeability of core samples at 260 m was much lower at 0.1 to 19 md.