Imaging seismic anisotropy in a shale gas reservoir by combining microseismic and 3D surface reflection seismic data
W. Gajek, J. Verdon, M. Malinowski and J. Trojanowski
Event name: 79th EAGE Conference and Exhibition 2017 - Workshops
Session: WS05 Linking Active and Passive Seismics
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 623.67Kb )
Price: € 20
A strong VTI fabric can dominate the influence of weaker azimuthal anisotropy on seismic wave propagation, causing ambiguities, making it challenging to invert geophysical observations for fracture orientations and densities. We employ SWS technique for a microseismic dataset collected in a vertical borehole during a hydraulic stimulation of a shale gas target in northern Poland to image the fracture strike and density masked by a strong VTI signature. In order to overcome VTI fabric influence and enhance the inversion stability we integrate SWS data with parameters obtained from the surface 3D seismic survey. We succesfully image a pre-existing vertical fracture set not aligned with the maximum horizontal stress. The obtained results are consistent with fracture strike and crack density interpreted from well logs data.