Abstract
We apply Laplace-Fourier 2D and 2.5D waveform tomography to a challenging wide-angle land data set from a geologically complex region in Japan. The survey line is crooked (up to 500 m deviation from the 2D line over the 16 km line length), and the area contains significant topographic relief (up to 400 m) and near-surface weathering layers. The lack of reflections previously prevented conventional reflection processing. We demonstrate that 2D acoustic waveform tomography is capable of extracting a reliable velocity model from refractions and wide-angle reflections with carefully designed data-preconditioning and inversion strategies. Sources and receivers are projected onto a 2D plane without preserving offsets: we eliminate traces where errors in offsets are large. We restrict the inversion to phase information at lowest frequencies, and discretize the model with a fine grid, in order to minimize the effects of the crooked line and the topography. We use balanced data amplitudes (using surface-consistent static deconvolution) to conduct the source estimation. We extensively validate the obtained velocity model by comparisons with a well log and observed waveforms, through scrutiny of the resulting reverse-timemigration image. An additional test with 2.5D waveform tomography demonstrates that 2D waveform inversion is adequate for these data.
Original language | English |
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Title of host publication | 76th European Association of Geoscientists and Engineers Conference and Exhibition 2014: Experience the Energy |
Place of Publication | Amsterdam, Netherlands |
Publisher | EAGE Publishing BV |
Pages | 4110-4114 |
Volume | 1 |
ISBN (Print) | 9781632666949 |
DOIs | |
Publication status | Published - 2014 |
Event | 76th European Association of Geoscientists and Engineers Conference and Exhibition 2014 - Amsterdam, Netherlands Duration: 16 Jun 2014 → 19 Jun 2014 |
Conference
Conference | 76th European Association of Geoscientists and Engineers Conference and Exhibition 2014 |
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Country/Territory | Netherlands |
City | Amsterdam |
Period | 16/06/14 → 19/06/14 |