Shot- and angle-domain wave-equation traveltime inversion of reflection data: Theory
Type
ArticleKAUST Department
Center for Subsurface Imaging and Fluid ModelingEarth Science and Engineering Program
Physical Science and Engineering (PSE) Division
Date
2015-05-26Online Publication Date
2015-05-26Print Publication Date
2015-07Permanent link to this record
http://hdl.handle.net/10754/556185
Metadata
Show full item recordAbstract
The main difficulty with iterative waveform inversion is that it tends to get stuck in local minima associated with the waveform misfit function. To mitigate this problem and avoid the need to fit amplitudes in the data, we have developed a wave-equation method that inverts the traveltimes of reflection events, and so it is less prone to the local minima problem. Instead of a waveform misfit function, the penalty function was a crosscorrelation of the downgoing direct wave and the upgoing reflection wave at the trial image point. The time lag, which maximized the crosscorrelation amplitude, represented the reflection-traveltime residual (RTR) that was back projected along the reflection wavepath to update the velocity. Shot- and angle-domain crosscorrelation functions were introduced to estimate the RTR by semblance analysis and scanning. In theory, only the traveltime information was inverted and there was no need to precisely fit the amplitudes or assume a high-frequency approximation. Results with synthetic data and field records revealed the benefits and limitations of wave-equation reflection traveltime inversion.Citation
Shot- and angle-domain wave-equation traveltime inversion of reflection data: Theory 2015, 80 (4):U47 GEOPHYSICSPublisher
Society of Exploration GeophysicistsJournal
GEOPHYSICSAdditional Links
http://library.seg.org/doi/abs/10.1190/geo2014-0178.1ae974a485f413a2113503eed53cd6c53
10.1190/geo2014-0178.1