LONG-PERIOD SURFACE-RELATED MULTIPLE SUPPRESSION IN 2D MARINE SEISMIC DATA USING PREDICTIVE DECONVOLUTION AND COMBINATION OF SURFACE-RELATED MULTIPLE ELIMINATION AND PARABOLIC RADON FILTERING

Author(s):  
Pimpawee Sittipan ◽  
Pisanu Wongpornchai

Some of the important petroleum reservoirs accumulate beneath the seas and oceans. Marine seismic reflection method is the most efficient method and is widely used in the petroleum industry to map and interpret the potential of petroleum reservoirs. Multiple reflections are a particular problem in marine seismic reflection investigation, as they often obscure the target reflectors in seismic profiles. Multiple reflections can be categorized by considering the shallowest interface on which the bounces take place into two types: internal multiples and surface-related multiples. Besides, the multiples can be categorized on the interfaces where the bounces take place, a difference between long-period and short-period multiples can be considered. The long-period surface-related multiples on 2D marine seismic data of the East Coast of the United States-Southern Atlantic Margin were focused on this research. The seismic profile demonstrates the effectiveness of the results from predictive deconvolution and the combination of surface-related multiple eliminations (SRME) and parabolic Radon filtering. First, predictive deconvolution applied on conventional processing is the method of multiple suppression. The other, SRME is a model-based and data-driven surface-related multiple elimination method which does not need any assumptions. And the last, parabolic Radon filtering is a moveout-based method for residual multiple reflections based on velocity discrimination between primary and multiple reflections, thus velocity model and normal-moveout correction are required for this method. The predictive deconvolution is ineffective for long-period surface-related multiple removals. However, the combination of SRME and parabolic Radon filtering can attenuate almost long-period surface-related multiple reflections and provide a high-quality seismic images of marine seismic data.

2021 ◽  
Vol 944 (1) ◽  
pp. 012005
Author(s):  
G L Situmeang ◽  
H M Manik ◽  
T B Nainggolan ◽  
Susilohadi

Abstract Wide range frequency bandwidth on seismic data is a necessity due to its close relation to resolution and depth of target. High-frequency seismic waves provide high-resolution imaging that defines thin bed layers in shallow sediment, while low-frequency seismic waves can penetrate into deeper target depth. As a result of broadband seismic technology, its wide range of frequency bandwidth is a suitable geophysical exploration method in the oil and gas industry. A major obstacle that is frequently found in marine seismic data acquisition is the existence of multiples. Short period multiple and reverberation are commonly attenuated by the predictive deconvolution method on prestack data. Advanced methods are needed to suppress long period multiple in marine seismic data. The 2D broadband marine seismic data from deep Morowali Waters, Sulawesi, contains both short and long period multiples. The predictive deconvolution, which is applied to the processing sequences, successfully eliminates short period multiple on prestack data. The combination of F-k filter and Surface Related Multiple Elimination (SRME) methods are successful in attenuating long period multiple of the 2D broadband marine seismic data. The Prestack Time Migration section shows fine resolution of seismic images.


2019 ◽  
Vol 34 (1) ◽  
Author(s):  
Tumpal Bernhard Nainggolan ◽  
Said Muhammad Rasidin ◽  
Imam Setiadi

Multiple often and always appear in marine seismic data due to very high acoustic impedance contrasts. These events have undergone more than one reflection. This causes the signal to arrive back at the receiver at an erroneous time, which, in turn, causes false results and can result in data misinterpretation. Several types of multiple suppression have been studied in literature. Methods that attenuate multiples can be classified into three broad categories: deconvolution methods; filtering methods and wavefield prediction subtraction methods. The study area is situated on Seram Sea in between 131°15’E – 132°45’E and 3°0’S – 4°0’S, Seram Trough which is located beneath Seram Sea at northern part of the Banda-Arc – Australian collision zone and currently the site of contraction between Bird’s Head and Seram. This research uses predictive deconvolution and FK-filter to attenuate short period multiple from their move out, then continued by SRME method to predict multiple that cannot be attenuated from previous method, then followed by Radon transform to attenuate multiple that still left and cannot be attenuated by SRME method. The result of each method then compared to each other to see how well multiple attenuated. Predictive deconvolution and F-K filter could not give satisfactory result especially complex area where multiple in dipping event is not periodic, SRME method successfully attenuate multiple especially in near offset multiple without need subsurface information, while SRME method fails to attenuate long offset multiple, combination of SRME method and Radon transform can give satisfactory result with careful selection of the Radon transform parameters because it can obscure some primary reflectors. Based on geological interpretation, Seram Trough is built by dominant structural style of deposited fold and thrust belt. The deposited fold and thrust belt has a complexly fault geometry from western zone until eastern of seismic line.


Geophysics ◽  
1989 ◽  
Vol 54 (1) ◽  
pp. 122-126 ◽  
Author(s):  
R. J. J. Hardy ◽  
M. R. Warner ◽  
R. W. Hobbs

The many techniques that have been developed to remove multiple reflections from seismic data all leave remnant energy which can cause ambiguity in interpretation. The removal methods are mostly based on periodicity (e.g., Sinton et al., 1978) or the moveout difference between primary and multiple events (e.g., Schneider et al., 1965). They work on synthetic and selected field data sets but are rather unsatisfactory when applied to high‐amplitude, long‐period multiples in marine seismic reflection data acquired in moderately deep (700 m to 3 km) water. Differential moveout is often better than periodicity at discriminating between types of events because, while a multiple series may look periodic to the eye, it is only exactly so on zero‐offset reflections from horizontal layers. The technique of seismic event labeling described below works by returning offset information from CDP gathers to a stacked section by color coding, thereby discriminating between seismic reflection events by differential normal moveout. Events appear as a superposition of colors; the direction of color fringes indicates whether an event has been overcorrected or undercorrected for its hyperbolic normal moveout.


2014 ◽  
Vol 32 (3) ◽  
pp. 395 ◽  
Author(s):  
Silmara L.R. Oliveira ◽  
Rosângela Corrêa Maciel ◽  
Michelângelo G. da Silva ◽  
Milton José Porsani

ABSTRACT. Short-period multiples attenuation is a difficult problem for shallow water marine seismic data processing. In the past few decades many filteringmethods have been developed to solve this problem and to improve the quality of seismic imaging. The Wiener-Levinson predictive deconvolution method is one of themost useful and well known filter methods used in the seismic data processing flow. It is a statistical approach to reduce redundancy along the time variable seismictrace, allowing us to both improve the time resolution and also attenuate multiple reflections of the seismic traces. One of the assumptions of the Wiener-Levinsonmethod is that the seismic wavelet is stationary along the entire seismic trace. However, this is not true for real seismic data and to bypass this limitation the methodis normally applied using fixed time windows, distributed along the seismic trace. The present study tested a new adaptive predictive deconvolution approach for theattenuation of short-period multiples. The new approach is based on a sliding window of fixed length that is shifted sample by sample along the entire seismic trace.At each position, a new filter is computed and applied. The implied systems of equations are solved by using a recursive Levinson-type algorithm. The main differencewith respect to the conventional Wiener-Levinson approach is that the filter is updated for each data sample along the trace and no assumption is imposed on the dataoutside the considered window. The new adaptive predictive deconvolution approach was tested using a seismic line of the Jequitinhonha Basin acquired by Petrobras.The results demonstrated that the new approach is very precise for the attenuation of short-period multiples, producing better results than the ones obtained fromthe conventional Wiener-Levinson predictive deconvolution approach. The results were obtained with filters of 25 coefficients, predictive distance of 5 samples andwindow length equal to 55 samples.Keywords: seismic processing, Jequitinhonha Basin, adaptive predictive deconvolution, multiple of attenuation, Wiener-Levinson deconvolution.RESUMO. A atenuação de reflexões múltiplas de curto período, presentes nos dados sísmicos adquiridos sobre lâmina d’água rasa, representa um grande problemado processamento de dados sísmicos marítimos. Nas últimas décadas, vários métodos de filtragem de dados sísmicos têm sido desenvolvidos com o propósito deatenuar reflexões múltiplas e melhorar a qualidade das seções sísmicas. O método de filtragem conhecido como deconvolução preditiva de Wiener-Levinson é bastante utilizado na indústria do petróleo. Ele permite melhorar a resolução temporal dos dados sísmicos e atenuar reflexões múltiplas, podendo ser visto como um método estatístico que remove a coerência temporal dos traços sísmicos. O método de Wiener-Levinson pressupõe que o pulso sísmico é estacionário, fato este que não ocorrenos dados sísmicos reais. Para contornar este problema, o método de Wiener-Levinson é normalmente aplicado utilizando-se janelas de tempo fixas, distribuídas ao longo do tempo de registro. No presente trabalho, empregamos um método de deconvolução preditiva adaptativa no qual as janelas de tempo deslizantes são deslocadas amostra a amostra ao longo de todo o traço sísmico. Os sistemas de equações são resolvidos com o algoritmo recursivo tipo-Levinson. Na deconvolução de Wiener-Levinson, com janelas de tempo fixa, os filtros são gerados e aplicados dentro de cada janela. Já na deconvolução preditiva adaptativa o algoritmo calcula um novo filtro a cada posição da janela deslizante. Para teste da nova abordagem utilizamos os dados sísmicos da Bacia de Jequitinhonha, cedidos pela Petrobras. Os melhores resultados foram obtidos com filtros de 25 coeficientes, distância de predição igual a 5 amostras e janela móvel de 55 amostras. Os resultados obtidos com a nova abordagem demonstram que a deconvolução preditiva adaptativa atua com eficácia na atenuação de múltiplas de curto período, apresentando resultados melhores queos gerados pelo método de deconvolução preditiva de Wiener-Levinson.Palavras-chave: processamento sísmico, Bacia do Jequitinhonha, deconvolução adaptativa, atenuação de múltiplas, deconvolução de Wiener-Levinson.


Geophysics ◽  
1997 ◽  
Vol 62 (5) ◽  
pp. 1628-1635 ◽  
Author(s):  
Andrew Burton ◽  
Larry Lines

One of the most difficult problems in the exploration of Devonian reefs is the separation of primaries and short period interbed multiples. This is especially true in cases where weak primary reflections from porous reefal carbonates can be easily masked by interbed multiples generated from stronger shale/carbonate reflections above the reef. This problem of primary‐multiple separation is difficult since there are small normal moveout differences between the primary and short‐period multiple reflections, thus stacking might not be as effective at suppressing multiples as one would hope. Also, predictive deconvolution may be ineffective if it is difficult to design an accurate prediction distance for the deconvolution filter. The ineffectiveness of stacking and deconvolution in some cases has caused us to look for other alternatives. A recent paper by Lines (1996) advocates the use of shaping deconvolution and inversion methods that use well log information. Since reliable well log data are not always available, we examine a vertical seismic profiling (VSP) corridor stacking method for multiple identification proposed in Hardage (1983, 154–155) which obviates some of the conventional problems and which does not require well log data. A variation of this concept was applied to long‐period multiple attenuation by Hampson and Mewhort (1983).


Geophysics ◽  
1983 ◽  
Vol 48 (7) ◽  
pp. 854-886 ◽  
Author(s):  
Ken Larner ◽  
Ron Chambers ◽  
Mai Yang ◽  
Walt Lynn ◽  
Willon Wai

Despite significant advances in marine streamer design, seismic data are often plagued by coherent noise having approximately linear moveout across stacked sections. With an understanding of the characteristics that distinguish such noise from signal, we can decide which noise‐suppression techniques to use and at what stages to apply them in acquisition and processing. Three general mechanisms that might produce such noise patterns on stacked sections are examined: direct and trapped waves that propagate outward from the seismic source, cable motion caused by the tugging action of the boat and tail buoy, and scattered energy from irregularities in the water bottom and sub‐bottom. Depending upon the mechanism, entirely different noise patterns can be observed on shot profiles and common‐midpoint (CMP) gathers; these patterns can be diagnostic of the dominant mechanism in a given set of data. Field data from Canada and Alaska suggest that the dominant noise is from waves scattered within the shallow sub‐buttom. This type of noise, while not obvious on the shot records, is actually enhanced by CMP stacking. Moreover, this noise is not confined to marine data; it can be as strong as surface wave noise on stacked land seismic data as well. Of the many processing tools available, moveout filtering is best for suppressing the noise while preserving signal. Since the scattered noise does not exhibit a linear moveout pattern on CMP‐sorted gathers, moveout filtering must be applied either to traces within shot records and common‐receiver gathers or to stacked traces. Our data example demonstrates that although it is more costly, moveout filtering of the unstacked data is particularly effective because it conditions the data for the critical data‐dependent processing steps of predictive deconvolution and velocity analysis.


Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. A25-A29
Author(s):  
Lele Zhang

Migration of seismic reflection data leads to artifacts due to the presence of internal multiple reflections. Recent developments have shown that these artifacts can be avoided using Marchenko redatuming or Marchenko multiple elimination. These are powerful concepts, but their implementation comes at a considerable computational cost. We have derived a scheme to image the subsurface of the medium with significantly reduced computational cost and artifacts. This scheme is based on the projected Marchenko equations. The measured reflection response is required as input, and a data set with primary reflections and nonphysical primary reflections is created. Original and retrieved data sets are migrated, and the migration images are multiplied with each other, after which the square root is taken to give the artifact-reduced image. We showed the underlying theory and introduced the effectiveness of this scheme with a 2D numerical example.


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