USE OF MULTIFRACTAL SEISMIC WAVEFORM PARAMETERS TO CHARACTERIZE THE HYDRAULIC PROPERTIES OF FRACTURED MEDIA: NUMERICAL EXPERIMENTS

Abstract

The multifractal characteristics of seismic waveforms that have propagated through fractured media were studied using numerical experiments. The study suggests that multifractal waveform parameters (i.e. information dimension, correlation dimension, curvature and range indices) bear correlations with the hydraulic properties of the fractured media. The characteristic waveform parameters were estimated from a multifractal analysis of 1-D synthetic seismograms generated using a variation of the reflectivity method. Waveforms from fractured zones were obtained by a superposition of reflections from horizontal fractures with a varying distribution of fracture length, aperture and spacing. The constructive and destructive interferences of the composite reflections from the fractures in the fractured layer result in waveforms that possess multifractal attributes. The characteristic parameters extracted from the waveforms are shown here to correlate with the hydraulic properties of the fractured rockmass, which include the fracture permeability, the discontinuity index and the fracture density parameter.