Joint microseismic location and anisotropic tomography using differential arrival times and differential backazimuths

TitleJoint microseismic location and anisotropic tomography using differential arrival times and differential backazimuths
Publication TypeJournal Article
Year of Publication2013
AuthorsLi, J, Zhang, H, Rodi, W, Toksoz, MN
JournalGeophysical Journal International
Volume195
Issue3
Pagination1917 - 1931
Date PublishedJan-12-2013
ISSN0956-540X
Abstract

We develop a new method to locate microseismic events induced by hydraulic fracturing with simultaneous anisotropic tomography, using differential arrival times and differential backazimuths. Compared to the existing double-difference method, our method incorporates backazimuth information to better constrain microseismic locations in the case of downhole linear seismic arrays used for monitoring induced seismicity. The tomography is constrained to a 1-D layered VTI (transversely isotropic structure with a vertical symmetry axis) structure to improve inversion stability given the limited passive seismic data. We derive analytical sensitivities for the elastic moduli (Cij) and layer thickness L, and verify the analytical results with numerical calculations. The forward modelled traveltimes and sensitivities are all calculated analytically without weak anisotropy assumption. By incorporating the relative information among events, the extended double-difference method can provide better relative locations for events and, therefore, can characterize the fractures with higher accuracy. In the two tests with synthetic data, our method provides more accurate relative locations than the traditional methods, which only use absolute information. With fast speed and high accuracy, our inversion scheme is suitable for real-time microseismic monitoring of hydraulic fracturing.

URLhttps://academic.oup.com/gji/article/195/3/1917/626577/Joint-microseismic-location-and-anisotropic
DOI10.1093/gji/ggt358
Short TitleGeophysical Journal International