Wave equation processing using finite-difference propagators, Part 2: Deghosting of marine hydrophone seismic data

Geophysics ◽  
2014 ◽  
Vol 79 (6) ◽  
pp. T301-T312 ◽  
Author(s):  
Johan O. A. Robertsson ◽  
Lasse Amundsen

We have developed a new and simple method for deghosting of conventional hydrophone streamer data towed at arbitrary variable depths. The method uses a time-space domain finite-difference (FD) solution to the wave equation with pressure field boundary conditions to predict and remove ghosts. Because it operates in the time domain, our method is unaffected by any number of notches in the frequency spectrum of the data and therefore will deghost “through notches.” Apart from the acquired hydrophone data, the method relies on the depth profile of the streamer recording the data beneath a sea surface with a known reflection coefficient as well as the propagation velocity in the water above the streamer. The method was applied to simple and more complex synthetic data, which illustrated its ability to deal with complex data and any acquisition geometry.

Geophysics ◽  
1997 ◽  
Vol 62 (6) ◽  
pp. 1817-1824 ◽  
Author(s):  
Hongbo Zhou ◽  
George A. McMechan

One‐pass 3-D modeling and migration for poststack seismic data may be implemented by replacing the traditional 45° one‐way wave equation (a third‐order partial differential equation) with a pair of second‐ and first‐order partial differential equations. Except for an extra correction term, the resulting second‐order equation has a form similar to the Claerbout 15° one‐way wave equation, which is known to have a nearly circular impulse response. In this approach, there is no need to compensate for splitting errors. Numerical tests on synthetic data show that this algorithm has the desirable attributes of being second order in accuracy and economical to solve. A modification of the Crank‐Nicholson implementation maintains stability.


2013 ◽  
Vol 56 (6) ◽  
pp. 840-850 ◽  
Author(s):  
LIANG Wen-Quan ◽  
YANG Chang-Chun ◽  
WANG Yan-Fei ◽  
LIU Hong-Wei

2017 ◽  
Vol 5 (1) ◽  
pp. T1-T9 ◽  
Author(s):  
Rui Zhang ◽  
Kui Zhang ◽  
Jude E. Alekhue

More and more seismic surveys produce 3D seismic images in the depth domain by using prestack depth migration methods, which can present a direct subsurface structure in the depth domain rather than in the time domain. This leads to the increasing need for applications of seismic inversion on the depth-imaged seismic data for reservoir characterization. To address this issue, we have developed a depth-domain seismic inversion method by using the compressed sensing technique with output of reflectivity and band-limited impedance without conversion to the time domain. The formulations of the seismic inversion in the depth domain are similar to time-domain methods, but they implement all the elements in depth domain, for example, a depth-domain seismic well tie. The developed method was first tested on synthetic data, showing great improvement of the resolution on inverted reflectivity. We later applied the method on a depth-migrated field data with well-log data validated, showing a great fit between them and also improved resolution on the inversion results, which demonstrates the feasibility and reliability of the proposed method on depth-domain seismic data.


Geophysics ◽  
2006 ◽  
Vol 71 (5) ◽  
pp. K103-K109 ◽  
Author(s):  
Qingyun Di ◽  
Meigen Zhang ◽  
Maioyue Wang

Many seismic data processing and inversion techniques have been applied to ground-penetrating radar (GPR) data without including the wave field attenuation caused by conductive ground. Neglecting this attenuation often reduces inversion resolution. This paper introduces a GPR inversion technique that accounts for the effects of attenuation. The inversion is formulated in the time domain with the synthetic GPR waveforms calculated by a finite-element method (FEM). The Jacobian matrix can be computed efficiently with the same FEM forward modeling procedure. Synthetic data tests show that the inversion can generate high-resolution subsurface velocity profiles even with data containing strong random noise. The inversion can resolve small objects not readily visible in the waveforms. Further, the inversion yields a dielectric constant that can help to determine the types of material filling underground cavities.


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