Stack velocity estimation trough a VFSA/Gauss-Newton hibrid algorithm

Oliveira, Danian Steinkirch de; Cunha, Paulo Eduardo Miranda; Porsani, Milton J.

doi:10.1190/sbgf2013-321

Cited by 2 publications

(1 citation statement)

References 6 publications

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“…In particular, global optimization strategies featuring very fast simulated annealing (VFSA; e.g. Garabito, 2018; Garabito & Cruz, 2019; Mesquita et al., 2019; Oliveira et al., 2013; Velis, 2021) have been successfully applied to real 2D and 3D data sets.…”

Section: Introductionmentioning

confidence: 99%

Efficient prestack time migration velocity analysis: A correlation‐based global optimization approach

Zhang

2023

Geophysical Prospecting

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An accurate migration velocity model is vital to seismic imaging. Conventional time‐domain migration velocity analysis techniques commonly obtain the velocity model by iteratively picking the velocity spectra of common reflection point gathers or scanning selection, which is usually laborious and computationally expensive. To solve these issues, we propose a more effective migration velocity analysis method for prestack time migration. This method is based on cross‐correlation stacked time shift functions of local migrated gathers and uses the very fast simulated annealing algorithm to semi‐automatically invert the migration velocity parameters. This new correlation‐based objective function can catch subtle bending features of the reflector in the local migrated gather. The proposed approach applies an efficient global optimization algorithm that does not depend on the initial parameter value and is easy to extend to the multiparameter complex case. Moreover, the strategy of using local migrated gathers can incorporate prior information in the inversion to avoid the effects of misidentifying reflection events and the interference of multiples. Furthermore, applying a dynamic parameter constraint strategy for the very fast simulated annealing algorithm improves the convergence speed. Both synthetic and real data examples demonstrate that the proposed migration velocity analysis method can efficiently build an accurate time migration velocity model, which can also provide a good initial velocity model for depth migration.

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Section: Introductionmentioning

confidence: 99%

Efficient prestack time migration velocity analysis: A correlation‐based global optimization approach

Zhang

2023

Geophysical Prospecting

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Improving prestack time migration by introducing a new velocity-related parameter: Parameter picking and 3D real data application

Xu,

Zhang

2023

GEOPHYSICS

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Prestack time migration (PSTM), a commonly used tool for seismic imaging, has been widely applied in 3D seismic data processing. However, the conventional PSTM algorithms use only one effective velocity parameter (i.e., rms velocity) for each imaging point, which may not be accurate when stronger lateral variations occur in seismic velocities. In this paper, we introduce a new parameter called the velocity variation factor that considers velocity variations in inhomogeneous media to improve PSTM. This new parameter, together with the rms velocity, describes the propagation Green function at an imaging point with two effective parameters rather than one effective parameter as in conventional PSTMs. This provides a more accurate traveltime calculation for the wave propagating through media with moderate lateral velocity variation. Unlike the conventional bending-ray PSTM, the additional effective parameter is fully independent of the rms velocities. We estimate the two effective parameters at each imaging point by flattening the neighboring image gathers with a global optimization algorithm. The objective function is built at each imaging point using a selective cross-correlation based time shift, which can quantitatively describe the slight bending of events in the local migrated gathers regardless of the quality of the gathers. We estimate the two effective parameters using the very fast simulated annealing (VFSA) algorithm and multiscale approach, thus avoiding the local minimum caused by the noises in the migrated gathers. We apply the proposed two-parameter PSTM to a real 3D land dataset to demonstrate its industrial applicability. A comparison of the new imaging result with the conventional prestack depth migration (PSDM) is also presented.

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Stack velocity estimation trough a VFSA/Gauss-Newton hibrid algorithm

Cited by 2 publications

References 6 publications

Efficient prestack time migration velocity analysis: A correlation‐based global optimization approach

Efficient prestack time migration velocity analysis: A correlation‐based global optimization approach

Improving prestack time migration by introducing a new velocity-related parameter: Parameter picking and 3D real data application

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