Using Multipath Shear Wave Arrivals for Enhanced Microseismic Location in Strongly Anisotropic Shale
A. Reshetnikov and S.A. Shapiro
Event name: 77th EAGE Conference and Exhibition 2015
Session: Microseismic Event Detection and Localization
Publication date: 01 June 2015
Info: Extended abstract, PDF ( 1.54Mb )
Price: € 20
In this work we consider a microseismic dataset acquired during a hydraulic stimulation of a shale gas reservoir in the Horn River Basin. We apply our common-receiver gather technique to analyze microseismic waveforms and to detect multiple arrivals of the slow shear wave. This information is extremely useful for velocity model inversion because it helps to constrain the anisotropy parameters in the target layer. We also show that even advanced microseismic monitoring system that includes two non vertical borehole receiver arrays may introduce ambiguity into a grid search based microseismic event location algorithm. To overcome this problem we present a location workflow that in addition to arrival times takes into account polarizations of the P-wave as well as crosscorelations between microseismic recordings. We show how this updated workflow improves quality of event localization.