Mendrii I. Prediction of fracture zones in coal-bearing formations from seismic data

The thesis is devoted actual problem of delineation of fracture zones in coal-bearing formations from seismic data. The genesis fractured zones of tectonic origin, which play a major role in the formation of coal bed methane (CBM) production sweet spots is considered. The main fracture characteristics important for the formation of CBM production sweet spots such as density, degree of disclosure, the geometry of the fracture network and their relationship are identified. Based on the analysis of existing techniques for detecting fracture zones from seismic data the use of such seismic attributes as coherence and curvature are justified. A new method for estimating coherence is developed. It is based on a more realistic model of seismic data that permits arbitrary variations of signal amplitudes and noise variances across the traces involved in coherence computation. Completed testing of the algorithms and their comparison with conventional counterparts on synthetic materials. A generalized approach to enhance the horizontal resolving power of any coherence measure has been suggested. The developed method for detecting fracture zones has been tested within the area of North-field Rodinsky mine "Krasnolimanska". The analysis of the field of seismic attributes in combination with tectonophysical studies revealed shear genesis of fracture zones.