Modeling Wave Propagation of Microseismic Events in Anisotropic Media
A. Oelke, O.S. Krueger and S.A. Shapiro
Event name: 76th EAGE Conference and Exhibition 2014
Session: Seismic Modelling III
Publication date: 16 June 2014
Info: Extended abstract, PDF ( 7.18Mb )
Price: € 20
Multiple wave front arrivals make it difficult, to identify reflections from hydraulic fractures within data recording microseismic events. The influence of anisotropy on the wave propagation can be huge and the shear wave splitting causes additional strong signals in the recorded wavefield. Interfaces within a heterogeneous velocity distribution can cause the occurrence of multiple wavefronts from reflections and conversions. However, in order to extract information from the recorded wavefield, it is crucial to understand it entirely. We numerically investigate the multiple wavefront arrivals of microseismic events in anisotropic heterogeneous media to support the interpretation of recorded wavefields. We investigate the influence of anisotropy and velocity inhomogeneities using numerical modeling based on a finite difference algorithm. Besides a huge shear wave splitting due to anisotropy, we indeed see significant features within the recorded wavefield caused by the velocity distribution. Different exemplary settings are given and discussed, such as a two-layer homogeneous anisotropic model and a complex model with properties extracted from the borehole log of a hydraulic fracturing treatment at Horn River Basin. Data of induced microseismic events within this anisotropic and heterogeneous environment are compared to the numerical results.