Cleat properties of the Tanjung Agung coalfield, South Sumatra Basin: implications to fluid flow

Abstract

Observation of the coal cleats of the Muara Enim Formation in Tanjung Agung coalfield aims to characterize the cleat properties and interpret their implications for fluid flow. This study used the scanline method to measure cleat attributes in the form of orientation, aperture, spacing, filler, and cleat connectivity. The face cleat was dominated by NE-SW direction as an indication of the effect of paleostress, while butt cleat with NW-SE direction indicated the effect of stress release. The presence of one major fault and three minor faults trending NW-SE in the mine pit is interpreted as the main controlling factor for cleat development in the study area. These cleats have an aperture ranging from 0.4 - 2.3 mm, good connectivity, and are not filled, so they are considered to be analogous to fluid flow paths with transition and turbulent flow types with relatively NE-SW direction.