Micro-seismic imaging using a source function independent full waveform inversion method
Type
ArticleAuthors
Wang, Hanchen
Alkhalifah, Tariq Ali

KAUST Department
Earth Science and Engineering ProgramPhysical Science and Engineering (PSE) Division
Seismic Wave Analysis Group
Date
2018-03-26Online Publication Date
2018-03-26Print Publication Date
2018-07-01Permanent link to this record
http://hdl.handle.net/10754/627425
Metadata
Show full item recordAbstract
At the heart of micro-seismic event measurements is the task to estimate the location of the source micro-seismic events, as well as their ignition times. The accuracy of locating the sources is highly dependent on the velocity model. On the other hand, the conventional micro-seismic source locating methods require, in many cases manual picking of traveltime arrivals, which do not only lead to manual effort and human interaction, but also prone to errors. Using full waveform inversion (FWI) to locate and image micro-seismic events allows for an automatic process (free of picking) that utilizes the full wavefield. However, full waveform inversion of micro-seismic events faces incredible nonlinearity due to the unknown source locations (space) and functions (time). We developed a source function independent full waveform inversion of micro-seismic events to invert for the source image, source function and the velocity model. It is based on convolving reference traces with these observed and modeled to mitigate the effect of an unknown source ignition time. The adjoint-state method is used to derive the gradient for the source image, source function and velocity updates. The extended image for the source wavelet in Z axis is extracted to check the accuracy of the inverted source image and velocity model. Also, angle gathers is calculated to assess the quality of the long wavelength component of the velocity model. By inverting for the source image, source wavelet and the velocity model simultaneously, the proposed method produces good estimates of the source location, ignition time and the background velocity for synthetic examples used here, like those corresponding to the Marmousi model and the SEG/EAGE overthrust model.Citation
Wang H, Alkhalifah T (2018) Micro-seismic imaging using a source function independent full waveform inversion method. Geophysical Journal International. Available: http://dx.doi.org/10.1093/gji/ggy121.Sponsors
We thank KAUST for sponsoring this research. We also thank to the team of SWAG for their help during the research.Publisher
Oxford University Press (OUP)ae974a485f413a2113503eed53cd6c53
10.1093/gji/ggy121