Correlation-based seismic velocity inversion

Leeuwen, Tristan van

doi:10.1190/1.3525284

Cited by 2 publications

(2 citation statements)

References 80 publications

(179 reference statements)

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“…However, I need to further test the approximations made in the modified gradient. Leeuwen (2010) showed that it is possible to further improve the objective function by multiplying with the proper weights and minimizing the correlation function instead of the lags, which will eliminate any picking. Finally, using correlation functions over extended images (Yang and Sava, 2009) could help provide better results.…”

Section: Discussionmentioning

confidence: 99%

Correlation‐based wave‐equation migration velocity analysis

Almomin

2011

SEG Technical Program Expanded Abstracts 2011

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Wave-equation migration velocity analysis (WEMVA) is a family of techniques that aim to improve the subsurface velocity model by minimizing the residual in the image space. Since the true image is unknown, measuring the residual in the image space is a challenge for WEMVA techniques. In this paper, I present a new method of measuring the image perturbation that is based on the cross-correlation of the observed image with a reference image in reflection angle gathers. I derive the gradient of this technique and show some synthetic examples that compare it to the optimum WEMVA gradient. I then modify the gradient in order to handle multiple events and show that it becomes immune to the problem of cycle skipping. I finally show a synthetic example of the modified gradient and compare it to the optimum gradient.

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Section: Discussionmentioning

confidence: 99%

Correlation‐based wave‐equation migration velocity analysis

Almomin

2011

SEG Technical Program Expanded Abstracts 2011

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“…Functionals that give more weight to the kinematic than to the amplitude error between the seismic arrivals. They often involve the cross-correlation between the observed and modelled arrivals (Luo & Schuster 1991;van Leeuwen & Mulder 2010;van Leeuwen 2010). After cross-correlation, the arrival-time error can be picked by hand, which is tedious and to be avoided if possible.…”

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confidence: 99%

Full waveform inversion with an auxiliary bump functional

Bharadwaj¹,

Mulder

Drijkoningen³

2016

Geophys. J. Int.

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S U M M A R YLeast-squares inversion of seismic arrivals can provide remarkably detailed models of the Earth's subsurface. However, cycle skipping associated with these oscillatory arrivals is the main cause for local minima in the least-squares objective function. Therefore, it is often difficult for descent methods to converge to the solution without an accurate initial large-scale velocity estimate. The low frequencies in the arrivals, needed to update the large-scale components in the velocity model, are usually unreliable or absent. To overcome this difficulty, we propose a multi-objective inversion scheme that uses the conventional least-squares functional along with an auxiliary data-domain objective. As the auxiliary objective effectively replaces the seismic arrivals by bumps, we call it the bump functional. The bump functional minimization can be made far less sensitive to cycle skipping and can deal with multiple arrivals in the data. However, it can only be used as an auxiliary objective since it usually does not provide a unique model after minimization even when the regularized-least-squares functional has a unique global minimum and hence a unique solution. The role of the bump functional during the multi-objective inversion is to guide the optimization towards the global minimum by pulling the trapped solution out of the local minima associated with the least-squares functional whenever necessary. The computational complexity of the bump functional is equivalent to that of the least-squares functional. In this paper, we describe various characteristics of the bump functional using simple and illustrative numerical examples. We also demonstrate the effectiveness of the proposed multi-objective inversion scheme by considering more realistic examples. These include synthetic and field data from a cross-well experiment, surface-seismic synthetic data with reflections and synthetic data with refracted arrivals at long offsets.

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Correlation-based seismic velocity inversion

Cited by 2 publications

References 80 publications

Correlation‐based wave‐equation migration velocity analysis

Correlation‐based wave‐equation migration velocity analysis

Full waveform inversion with an auxiliary bump functional

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