Thickness Prediction of Tectonically Deformed Coal Using Calibrated Seismic Attributes: A Case Study

Abstract

Tectonically deformed coal is a key factor affecting the phenomena of gas outbursts in coal mines. Seismic attributes associated with coal-bed reflections can represent this kind of coal, but the representation is indirect and ambiguous since both coal-bed thickness and lithology can affect the attributes. We propose a model-based function to calibrate seismic attributes from thin coal-bed reflections, and use the calibrated attributes to estimate the distribution of tectonically deformed coal. To eliminate the influence of coal-bed thickness on seismic attributes, we first build a synthetic model to simulate true geological condition of the coal bed. Then, we extract seismic attributes from the synthetic section and cross plotted the correlations between attributes and thickness. After the fitting of cross-plotted correlations with a Fourier series, we estimate the calibration functions of the attributes. Finally, true attributes of a mining zone are calibrated with those functions. The results presented here show much more observable correlation with the thickness of tectonically deformed coal than uncalibrated attributes.