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Microseismic Elastic Full Waveform Inversion for Hydraulic Fracture Monitoring
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 74th EAGE Conference and Exhibition incorporating EUROPEC 2012, Jun 2012, cp-293-00094
- ISBN: 978-90-73834-27-9
Abstract
Simultaneous microseismic inversion for event locations and full source moment tensors enables a greater understanding of reservoir behaviour and can help optimize hydraulic fracture effectiveness. We develop an elastic full waveform inversion algorithm that is applied to 3C multi-well microseismic data. This is a single-stage downhole hydraulic fracture monitoring experiment from an unconventional play in North America. The algorithm minimizes least squares differences between complete observed and synthetic elastic P+S vector waveforms (after Q compensation) in order to determine event coordinates and the full moment tensor. Finite-difference Green’s functions for the VTI medium are used to compute the radiated seismic waves for the arbitrary force system. We utilize the Hudson’s source plot to analyze both the best fit double-couple (DC) solutions and departures from the DC model due to tensile failures. The final inversion workflow addresses uncertainties due to an inaccurate velocity model, a mislocated source and noisy waveforms. We demonstrate both the robustness of the full waveform inversion and the reduced bias of our results when compared with conventional inversion methods based on traveltimes and amplitudes. This leads to increased knowledge and reduced uncertainties of microseismic fracture monitoring that help maximize production and reservoir drainage in unconventional plays.