Data-driven multichannel seismic impedance inversion with anisotropic total variation regularization

2018 ◽  
Vol 26 (2) ◽  
pp. 229-241 ◽  
Author(s):  
Dehua Wang ◽  
Jinghuai Gao ◽  
Hongan Zhou
Keyword(s):  
Total Variation ◽  
Seismic Data ◽  
Reservoir Characterization ◽  
Data Driven ◽  
Total Variation Regularization ◽  
Split Bregman ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Impedance Inversion ◽  
Anisotropic Total Variation

AbstractAcoustic impedance (AI) inversion is a desirable tool to extract rock-physical properties from recorded seismic data. It plays an important role in seismic interpretation and reservoir characterization. When one of recursive inversion schemes is employed to obtain the AI, the spatial coherency of the estimated reflectivity section may be damaged through the trace-by-trace processing. Meanwhile, the results are sensitive to noise in the data or inaccuracies in the generated reflectivity function. To overcome the above disadvantages, in this paper, we propose a data-driven inversion scheme to directly invert the AI from seismic reflection data. We first explain in principle that the anisotropic total variation (ATV) regularization is more suitable for inverting the impedance with sharp interfaces than the total variation (TV) regularization, and then establish the nonlinear objective function of the AI model by using anisotropic total variation (ATV) regularization. Next, we solve the nonlinear impedance inversion problem via the alternating split Bregman iterative algorithm. Finally, we illustrate the performance of the proposed method and its robustness to noise with synthetic and real seismic data examples by comparing with the conventional methods.

Band-limited scattered wavefield reconstruction beneath complex overburdens using the Marchenko method

2021 ◽  
Author(s):  
David Vargas ◽  
Ivan Vasconcelos ◽  
Matteo Ravasi
Keyword(s):  
Seismic Data ◽  
Reservoir Characterization ◽  
Accurate Estimation ◽  
Target Area ◽  
Complex Media ◽  
Depth Level ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Band Limited ◽  
Internal Multiples

<p>Structural imaging beneath complex overburdens, such as sub-salt or sub-basalt, typically characterized by high-impedance contrasts represents a major challenge for state-of-the-art seismic methods. Reconstructing complex geological structures in the vicinity of and below salt bodies is challenging not only due to uneven, single-sided illumination of the target area but also because of the imperfect removal of surface and internal multiples from the recorded data, as required by traditional migration algorithms. In such tectonic setups, most of the downgoing seismic wavefield is reflected toward the surface when interacting with the overburden's top layer. Similarly, the sub-salt upcoming energy is backscattered at the salt's base. Consequently, the actual energy illuminating the sub-salt reflectors, recorded at the surface, is around the noise level. In diapiric trap systems, conventional seismic extrapolation techniques do not guarantee sufficient quality to reduce exploration and production risks; likewise, seismic-based reservoir characterization and monitoring are also compromised. In this regard, accurate wavefield extrapolation techniques based on the Marchenko method may open up new ways to exploit seismic data.</p><p>The Marchenko redatuming technique retrieves reliable full-wavefield information in the presence of geologic intrusions, which can be subsequently used to produce artefact-free images by naturally including all orders of multiples present in seismic reflection data. To achieve such a goal, the method relies on the estimation of focusing operators allowing the synthesis of virtual surveys at a given depth level. Still, current Marchenko implementations do not fully incorporate available subsurface models with sharp contrasts, due to the requirements regarding the initialization of the focusing functions. Most importantly, in complex media, even a fairly accurate estimation of a direct wave as a proxy for the required initial focusing functions may not be enough to guarantee sufficiently accurate wavefield reconstruction.</p><p>In this talk, we will discuss a scattering-based Marchenko redatuming framework which improves the redatuming of seismic surface data in highly complex media when compared to other Marchenko-based schemes. This extended version is designed to accommodate for band-limited, multi-component, and possibly unevenly sampled seismic data, which contain both free-surface and internal multiples, whilst requiring minimum pre-processing steps. The performance of our scattering Marchenko method will be evaluated using a comprehensive set of numerical tests on a complex 2D subsalt model.</p>

Broadband seismic data — The importance of low frequencies

Geophysics ◽  
2013 ◽  
Vol 78 (2) ◽  
pp. WA3-WA14 ◽  
Author(s):  
Fons ten Kroode ◽  
Steffen Bergler ◽  
Cees Corsten ◽  
Jan Willem de Maag ◽  
Floris Strijbos ◽  
...  
Keyword(s):  
Research And Development ◽  
Experimental Evidence ◽  
Case Studies ◽  
Seismic Data ◽  
Seismic Reflection ◽  
Low Frequencies ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Enhanced Resolution ◽  
Impedance Inversion

We considered the importance of low frequencies in seismic reflection data for enhanced resolution, better penetration, and waveform and impedance inversion. We reviewed various theoretical arguments underlining why adding low frequencies may be beneficial and provided experimental evidence for the improvements by several case studies with recently acquired broadband data. We discussed where research and development efforts in the industry with respect to low frequencies should be focusing.

Potentially Large Subsurface Gas Hydrate Bodies in the Mexican Ridges, Southwestern Gulf of Mexico

2021 ◽  
pp. 1-29
Author(s):  
Papia Nandi ◽  
Patrick Fulton ◽  
James Dale
Keyword(s):  
Gulf Of Mexico ◽  
Gas Hydrate ◽  
Seismic Data ◽  
Poor Quality ◽  
Reflection Point ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
High Impedance ◽  
Acoustic Velocities ◽  
Seismic Images

As rising ocean temperatures can destabilize gas hydrate, identifying and characterizing large shallow hydrate bodies is increasingly important in order to understand their hazard potential. In the southwestern Gulf of Mexico, reanalysis of 3D seismic reflection data reveals evidence for the presence of six potentially large gas hydrate bodies located at shallow depths below the seafloor. We originally interpreted these bodies as salt, as they share common visual characteristics on seismic data with shallow allochthonous salt bodies, including high-impedance boundaries and homogenous interiors with very little acoustic reflectivity. However, when seismic images are constructed using acoustic velocities associated with salt, the resulting images were of poor quality containing excessive moveout in common reflection point (CRP) offset image gathers. Further investigation reveals that using lower-valued acoustic velocities results in higher quality images with little or no moveout. We believe that these lower acoustic values are representative of gas hydrate and not of salt. Directly underneath these bodies lies a zone of poor reflectivity, which is both typical and expected under hydrate. Observations of gas in a nearby well, other indicators of hydrate in the vicinity, and regional geologic context, all support the interpretation that these large bodies are composed of hydrate. The total equivalent volume of gas within these bodies is estimated to potentially be as large as 1.5 gigatons or 10.5 TCF, considering uncertainty for estimates of porosity and saturation, comparable to the entire proven natural gas reserves of Trinidad and Tobago in 2019.

scholarly journals Improved Interpretation of Deep Seismic Reflection Data in Areas of Complex Geology Through Integration With Passive Seismic Data Sets

2018 ◽  
Vol 123 (12) ◽  
pp. 10,810-10,830
Author(s):  
Michael Dentith ◽  
Huaiyu Yuan ◽  
Ruth Elaine Murdie ◽  
Perla Pina-Varas ◽  
Simon P. Johnson ◽  
...  
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Data Sets ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data ◽  
Passive Seismic ◽  
Complex Geology

Late Cretaceous – Cenozoic history of the transition zone between the East European Craton and the Paleozoic Platform, Polish sector of the Baltic Sea, revealed by new offshore regional seismic reflection data (BALTEC project)

2021 ◽  
Author(s):  
Piotr Krzywiec ◽  
Łukasz Słonka ◽  
Quang Nguyen ◽  
Michał Malinowski ◽  
Mateusz Kufrasa ◽  
...  
Keyword(s):  
High Resolution ◽  
Late Cretaceous ◽  
Seismic Data ◽  
Seismic Reflection ◽  
Upper Cretaceous ◽  
Seismic Reflection Data ◽  
East European ◽  
Reflection Data ◽  
Multichannel Seismic Reflection ◽  
Multichannel Seismic Reflection Data

<p>In 2016, approximately 850 km of high-resolution multichannel seismic reflection data of the BALTEC survey have been acquired offshore Poland within the transition zone between the East European Craton and the Paleozoic Platform. Data processing, focused on removal of multiples, strongly overprinting geological information at shallower intervals, included SRME, TAU-P domain deconvolution, high resolution parabolic Radon demultiple and SWDM (Shallow Water De-Multiple). Entire dataset was Kirchhoff pre-stack time migrated. Additionally, legacy shallow high-resolution multichannel seismic reflection data acquired in this zone in 1997 was also used. All this data provided new information on various aspects of the Phanerozoic evolution of this area, including Late Cretaceous to Cenozoic tectonics and sedimentation. This phase of geological evolution could be until now hardly resolved by analysis of industry seismic data as, due to limited shallow seismic imaging and very strong overprint of multiples, essentially no information could have been retrieved from this data for first 200-300 m. Western part of the BALTEC dataset is located above the offshore segment of the Mid-Polish Swell (MPS) – large anticlinorium formed due to inversion of the axial part of the Polish Basin. BALTEC seismic data proved that Late Cretaceous inversion of the Koszalin – Chojnice fault zone located along the NE border of the MPS was thick-skinned in nature and was associated with substantial syn-inversion sedimentation. Subtle thickness variations and progressive unconformities imaged by BALTEC seismic data within the Upper Cretaceous succession in vicinity of the Kamień-Adler and the Trzebiatów fault zones located within the MPS documented complex interplay of Late Cretaceous basin inversion, erosion and re-deposition. Precambrian basement of the Eastern, cratonic part of the study area is overlain by Cambro-Silurian sedimentary cover. It is dissected by a system of steep, mostly reverse faults rooted in most cases in the deep basement. This fault system has been regarded so far as having been formed mostly in Paleozoic times, due to the Caledonian orogeny. As a consequence, Upper Cretaceous succession, locally present in this area, has been vaguely defined as a post-tectonic cover, locally onlapping uplifted Paleozoic blocks. New seismic data, because of its reliable imaging of the shallowest substratum, confirmed that at least some of these deeply-rooted faults were active as a reverse faults in latest Cretaceous – earliest Paleogene. Consequently, it can be unequivocally proved that large offshore blocks of Silurian and older rocks presently located directly beneath the Cenozoic veneer must have been at least partly covered by the Upper Cretaceous succession; then, they were uplifted during the widespread inversion that affected most of Europe. Ensuing regional erosion might have at least partly provided sediments that formed Upper Cretaceous progradational wedges recently imaged within the onshore Baltic Basin by high-end PolandSPAN regional seismic data. New seismic data imaged also Paleogene and younger post-inversion cover. All these results prove that Late Cretaceous tectonics substantially affected large areas located much farther towards the East than previously assumed.</p><p>This study was funded by the Polish National Science Centre (NCN) grant no UMO-2017/27/B/ST10/02316.</p>

Anisotropic Total Variation Guided Filtering and Its Split Bregman Algorithm

2017 ◽  
Vol 54 (5) ◽  
pp. 051005
Author(s):  
芦碧波 Lu Bibo ◽  
王乐蓉 Wang Lerong ◽  
王永茂 Wang Yongmao ◽  
郑艳梅 Zheng Yanmei
Keyword(s):  
Total Variation ◽  
Split Bregman ◽  
Guided Filtering ◽  
Split Bregman Algorithm ◽  
Anisotropic Total Variation

scholarly journals Performance of relaxed iterative methods for image deblurring problems

2019 ◽  
Vol 13 ◽  
pp. 174830261986173 ◽  
Author(s):  
Jae H Yun
Keyword(s):  
Fixed Point ◽  
Iterative Methods ◽  
Total Variation ◽  
Numerical Experiments ◽  
Krylov Subspace ◽  
Image Deblurring ◽  
Total Variation Regularization ◽  
L1 Norm ◽  
Split Bregman ◽  
Relaxation Parameters

In this paper, we consider performance of relaxation iterative methods for four types of image deblurring problems with different regularization terms. We first study how to apply relaxation iterative methods efficiently to the Tikhonov regularization problems, and then we propose how to find good preconditioners and near optimal relaxation parameters which are essential factors for fast convergence rate and computational efficiency of relaxation iterative methods. We next study efficient applications of relaxation iterative methods to Split Bregman method and the fixed point method for solving the L1-norm or total variation regularization problems. Lastly, we provide numerical experiments for four types of image deblurring problems to evaluate the efficiency of relaxation iterative methods by comparing their performances with those of Krylov subspace iterative methods. Numerical experiments show that the proposed techniques for finding preconditioners and near optimal relaxation parameters of relaxation iterative methods work well for image deblurring problems. For the L1-norm and total variation regularization problems, Split Bregman and fixed point methods using relaxation iterative methods perform quite well in terms of both peak signal to noise ratio values and execution time as compared with those using Krylov subspace methods.

Fault whispers: Transmission distortions on prestack seismic reflection data

Geophysics ◽  
2000 ◽  
Vol 65 (2) ◽  
pp. 377-389 ◽  
Author(s):  
Paul J. Hatchell
Keyword(s):  
Seismic Data ◽  
Seismic Waves ◽  
Shallow Gas ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Amplitude Versus Offset ◽  
Velocity Changes ◽  
Transmission Distortions ◽  
Amplitude Versus ◽  
Buried Faults

Transmission distortions are observed on prestack seismic data at two locations in the Gulf of Mexico. These distortions produce anomalous amplitude versus offset (AVO) signatures. The locations of the distortion zones are determined using acquisition geometry and ray tracing. No obvious reflection events, such as shallow gas zones, are observed at the predicted locations of the distortion zones. Instead, the distortion zones correlate with buried faults and unconformities. It is postulated that the distortions are produced by velocity changes across buried faults and unconformities. The distortions result from an interference pattern resulting from seismic waves arriving from different sides of the faults. A simple model is developed to explain many of the characteristics of the distortion pattern.

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