ABSTRACT
Many of the problems experienced during extraction of coal are directly related to geological disruptions in the continuity of the seam. These disruptions may be both sedimentological and structural. Previous models of the Witbank coalfield were developed some 15 to 20 years ago and the wealth of information that has accumulated since then has not been utilized. In addition, these models were unable to examine the three dimensional aspect of sediment distribution, due to limited computing power and have ignored the geotechnical aspects, such as roof and floor stability. The newly established model is developed through the integration of borehole information as part of the COALTECH 2020 research program. Borehole data, digital elevation models from satellite imagery and regional scale aeromagnetic data has been integrated. The coal seams and their sediments are split into a series of on-lapping geological domains based on the facies association of the different rock types. These facies are based on the mine-scale models of previous workers but have been extended and refined to the entire basin. Within the 3D model it is possible to visualize the complex inter-relationship of these facies and hence predict their distribution in unmined areas and areas of limited mining.
