• Geophysics and Geophysical Exploration
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• v.12 no.4
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• pp.289-298
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• 2009

Optimal data processing parameters were designed to attenuate multiples in seismic data acquired in the south-eastern area of the East Sea, in 2008. Bunch of multiples caused by shallow sea water depth were perceived periodically up to two way travel time of 1,750 ms at every 250 ms over seismic traces. We abbreviated sea bottom multiple as SBM, Peg-leg multiple as PLM, and free-surface multiple as FSM. To attenuate these multiples, seismic data processing flow was constructed including NMO, stack, minimum phase predictive deconvolution filter and wave equation multiple rejections (WEMR). Prevalent multiples were suppressed by predictive deconvolution and remaining multiples were attenuated by WEMR. We concluded that combining deconvolution with WEMR was effective to a seismic data of study area. Derived parameter can be applied to the seismic data processing on adjacent survey area.

• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.279-285
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• 2008

Korea Institute of Geoscience & Mineral Resources (KIGAM) carried out 2 dimensional multi-channel seismic surveys for Domi-Basin of east-southern part of Jeju Island, South Sea, Korea in 2007. The purpose of this survey is to investigate the structure of acoustic basement and the potential of energy resources in the Korean shelf. It is essential to produce fine stack and migration section to understand the structure of basement. However a basement can not be clearly defined where multiples exist between sea surface and seafloor. This study aimed at designing the optimal data processing parameter, especially to eliminate the peg-leg multiples. Main data processing procedure is composed of minimum phase predictive deconvolution, velocity analysis and Radon filter. We tested the efficiency of processing parameter from stack sections of each step. Our results confirmed that processing parameters are suitable for the seismic data of Domi-Basin.

• Economic and Environmental Geology
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• v.29 no.5
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• pp.629-637
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• 1996

In this paper a numerical experiment is conducted to determine the low acoustic impedance of a thin oil or gas reservoir from a seismogram by using the generalized linear inversion method. The seismograms used are normal incident synthetic seismograms containing p-wave primary reflections, multiples, and peg-leg multiples on the layers consisting of oil-, gas-, water-filled sandstone incased in shales. In this experiment the acoustic impedance, the location of reservoir boundary, thickness, and source wavelet are assumed initially and revised iteratively by the least-squares-error technique until the difference between the seismogram and calculated one is very small. This experiment shows that the acoustic impedance and thickness, about 10 m thick, can be determined by the inversion.

• The Korean Journal of Petroleum Geology
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• v.11 no.1 s.12
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• pp.9-17
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• 2005

In the main target area of the block II, Targe-scale faults occur below the unconformity developed around 1 km in depth. The contrast of seismic velocity around the unconformity is generally so large that the strong multiples and the radical velocity variation would deteriorate the quality of migrated section due to serious distortion. More than 15 kinds of data processing techniques have been applied to improve the image resolution for the structures farmed from this active crustal activity. The bad and noisy traces were edited on the common shot gathers in the first step to get rid of acquisition problems which could take place from unfavorable conditions such as climatic change during data acquisition. Correction of amplitude attenuation caused from spherical divergence and inelastic attenuation has been also applied. Mild F/K filter was used to attenuate coherent noise such as guided waves and side scatters. Predictive deconvolution has been applied before stacking to remove peg-leg multiples and water reverberations. The velocity analysis process was conducted at every 2 km interval to analyze migration velocity, and it was iterated to get the high fidelity image. The strum noise caused from streamer was completely removed by applying predictive deconvolution in time space and ${\tau}-P$ domain. Residual multiples caused from thin layer or water bottom were eliminated through parabolic radon transform demultiple process. The migration using curved ray Kirchhoff-style algorithm has been applied to stack data. The velocity obtained after several iteration approach for MVA (migration velocity analysis) was used instead or DMO for the migration velocity. Using various testing methods, optimum seismic processing parameter can be obtained for structural and stratigraphic interpretation in the Block II, Yellow Sea Basin.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.603-613
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• 2010

The Domi Basin in the South Sea of Korea is located between the Jeju Basin and Ulleung Basins, and is characterized by several sediment sags that are interested to have formed by crustal extension. This paper aims to derive an optimized seismic data processing procedure which helps stratigraphic interpretation of the Domi Basin. In particular, our data processing flow incorporated horizon velocity analysis (HVA) and surface-relative wave equation multiple rejection (SRWEMR) to improve the quality of stack section by enhancing the continuity of reflection events and suppressing peg-leg multiples respectively. As a result of processing procedures in this study, unconformities were recognized in the stack section that defines the early and middle Miocene, Eocene-Oligocene sequences. In addition, the overall quality of the stack section was increased as essential data to investigate the evolution of the basin. The suppression of multiple resulted in the identification of the Cretaceous basement. The data processing scheme evaluated through this study is expected to improve the standardization of processing sequences for seismic data from the Domi and adjacent Sora and north-Sora Basins.