--> --> Cleats Analysis and CBM potential of The Barito Basin, South Kalimantan, Indonesia

International Conference & Exhibition

Datapages, Inc.Print this page

Cleats Analysis and CBM potential of The Barito Basin, South Kalimantan, Indonesia

Abstract

The study area is located at the Barito Basin, South Kalimantan Province known as major coal producer basin in Indonesia. Cleats are described as a natural fractures developed in coal seams and acted as the main parameters in controlling permeability performance in the coal bed methane development. Therefore, the knowledge of origin and character cleats is very important because of their influence on recovery of methane, and the local and regional fluid flows. This paper is presented results of integrated surface to subsurface data supported by regional cleats mapping, characterization and analysis in relation to Coal Bed Methane (CBM) exploration and development in the basin. There are two main coal seams in the study area, Late Eocene and Lower to Middle Miocene of Warukin Fm. with thickness ranging from 2 m up to 60 m. Subsurface data show three different coal zone observed from six well data. The occurence of coal seams in each wells are based on value of RHOB with 1.75 as cut off value. Coal rank are classified as Lignite - Sub Bituminous C with calorific values ranging 5000 – 8000 Cal/gr containing Ash content of 8%-17%. There are two methods of cleat and/or fracture measurements used in this study: scan-line and windows sampling (100 cm × 100 cm dimension). More than 20,000 cleats and/or fractures were measured from 60 scan-lines and 39 windows measurement locations. Cleats distribution and orientation indicates three major orientations WNW-ESE, NNW-SSE, and NE-SW trending. They are: an inverse linear is the best fit data for the bed thickness-density relationship, an exponential relationship between average density and cleats height, a power-law relationship between average density and average spacing, and cleats density increases related to regional structural position where they increases towards main deformation zone (Meratus Mountain). Cleats spacing varies with coal type and ash contents. Relationship between cleats spacing and coal rank, spacing indicates decreasing from low to high rank coal. Relationship between cleats density with calorific value and ash contents showing general relationship where high calorific value with low ash content tends to have large density. This cleats origin might be subjected from several processes, where the cleats, which formed during coalification, can be superimposed by later processes such as hydrostatic pressure and tectonic stresses and also can be affected by the coal composition.