Improving 3D water column seismic imaging using the Common Reflection Surface method

The extraction of kinematic parameters from wave propagation through traveltimes is one of the great challenges in seismic data processing. In this context, we modify the common-reflection-surface (CRS) traveltime to improve its accuracy and also interpret its parameters via paraxial ray theory in an anisotropic medium obtaining information about the wavefront curvatures measured at surface. The proposed method consists of searching for the best stacking parameters that fit the data set followed by the extraction of kinematic information from the measured waves. Numerical tests show the effectiveness of our assumptions and that the results obtained in the fitting and parameter extraction in anisotropic media achieve better accuracy than conventional CRS.

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CHOLANGITIS AS A SYSTEMIC MANIFESTATION OF ACUTE BILIARY INFECTION

International Medical Journal ◽

10.37436/2308-5274-2020-2-9 ◽

2020 ◽

pp. 43-47

Author(s):

A. O. Nekludov ◽

M. O. Klosova ◽

O. V. Volchenko ◽

M. M. Goloborodko ◽

A. Yu. Korolevska

Keyword(s):

Bile Duct ◽

Common Bile Duct ◽

Water Column ◽

Biliary Tract ◽

Bile Ducts ◽

Inflammatory Process ◽

Acute Cholangitis ◽

Biliary Infection ◽

The Common ◽

Further Development

The main causes of cholangitis are hypertension in the biliary ducts and infection. In order to determine the place of the infectious factor in the acute cholangitis development, a retrospective and prospective analysis of case histories of 176 patients with choledocholithiasis and manifestations of acute and chronic cholangitis was performed. Bile from the common bile duct in the patients with obstruction of the biliary tract was studied. In the patients with mechanical jaundice without and with cholangitis, the intraductal pressure in the common bile duct averaged 227.3±26.1 mm of water column, in the patients without signs of cholangitis that was 97.5±8.3 mm of water column. With mechanical jaundice without acute cholangitis, it was slightly elevated if compared to normal. This suggests that the increase in pressure in the bile ducts in acute cholangitis is not influenced by the fact of obstruction of the biliary tract, and the development of the inflammatory process in them. In the patients with cholangitis, the initial values of the number of colonizing units were much higher than in "pure" choledocholithiasis. After endoscopic papillosphincterotomy in the patients with vivid clinical cholangitis, in whom decompression was achieved, in the control study, this value decreased by 100−500 times, which was accompanied by clinical improvement. According to the results of the study, it was noted that in the patients with a manifested clinic sign of cholangitis there is a significant decrease in the number of colonizing units on the third day after endoscopic papillosphincterotomy. At the stone stuck in a papilla the choledoch turns into so−called analog of an abscess. The opening of the papilla provides a free passage of the contents of the choledochus (i.e. pus) into the duodenum, so there is an almost instant therapeutic effect. The increase in pressure in the bile ducts in acute cholangitis is influenced by the development of an inflammatory process, which indicates the manifestations of biliary infection. The presented research has a prospective character and needs further development. Key words: cholangitis, biliary infection, intraductal pressure, bile.

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Application of the Common Reflection Surface (CRS) Stack to Crustal Reflection Data

69th EAGE Conference and Exhibition incorporating SPE EUROPEC 2007 ◽

10.3997/2214-4609.201401959 ◽

2007 ◽

Author(s):

M. Yoon ◽

M. Baykulov ◽

S. Dümmong ◽

H. J. Brink ◽

D. Gajewski

Keyword(s):

Reflection Data ◽

Common Reflection Surface ◽

The Common ◽

Crustal Reflection

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Velocity-estimation improvements and migration/demigration using the common-reflection surface with continuing deconvolution in the time domain

Geophysics ◽

10.1190/geo2018-0173.1 ◽

2019 ◽

Vol 84 (4) ◽

pp. S229-S238 ◽

Cited By ~ 1

Author(s):

Martina Glöckner ◽

Sergius Dell ◽

Benjamin Schwarz ◽

Claudia Vanelle ◽

Dirk Gajewski

Keyword(s):

Model Building ◽

Velocity Model ◽

Velocity Estimation ◽

Initial Time ◽

Model Errors ◽

Imaging Methods ◽

Time Migration ◽

Common Reflection Surface ◽

The Common ◽

And Migration

To obtain an image of the earth’s subsurface, time-imaging methods can be applied because they are reasonably fast, are less sensitive to velocity model errors than depth-imaging methods, and are usually easy to parallelize. A powerful tool for time imaging consists of a series of prestack time migrations and demigrations. We have applied multiparameter stacking techniques to obtain an initial time-migration velocity model. The velocity model building proposed here is based on the kinematic wavefield attributes of the common-reflection surface (CRS) method. A subsequent refinement of the velocities uses a coherence filter that is based on a predetermined threshold, followed by an interpolation and smoothing. Then, we perform a migration deconvolution to obtain the final time-migrated image. The migration deconvolution consists of one iteration of least-squares migration with an estimated Hessian. We estimate the Hessian by nonstationary matching filters, i.e., in a data-driven fashion. The model building uses the framework of the CRS, and the migration deconvolution is fully automated. Therefore, minimal user interaction is required to carry out the velocity model refinement and the image update. We apply the velocity refinement and migration deconvolution approaches to complex synthetic and field data.

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Approximate inverse for the common offset acquisition geometry in 2D seismic imaging

Inverse Problems ◽

10.1088/1361-6420/aa9900 ◽

2017 ◽

Vol 34 (1) ◽

pp. 014002 ◽

Cited By ~ 2

Author(s):

Christine Grathwohl ◽

Peer Kunstmann ◽

Eric Todd Quinto ◽

Andreas Rieder

Keyword(s):

Seismic Imaging ◽

Approximate Inverse ◽

The Common

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Nickel Deposition on Pre-Electroless Plated Ni-P-B Coating on Quartz Optical Fiber in a Lanthanide Oxide-Added Watt Electroplating Bath

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.199-200.421 ◽

2011 ◽

Vol 199-200 ◽

pp. 421-425

Author(s):

Bo Quan Jiang ◽

Jiang Nan Zeng ◽

Yu De Liu ◽

Xiao Hong Liu

Keyword(s):

Optical Fiber ◽

Deposition Rate ◽

Current Density ◽

Fiber Surface ◽

Nickel Deposition ◽

Lanthanide Oxide ◽

Surface Method ◽

Quartz Optical Fiber ◽

The Common ◽

Experimental Values

Lanthanide oxide was added into the common Watt bath to make a thick nickel on the Ni-P-B coating on the quartz optical fiber surface by response surface method. The experiment showed the optimum concentrations of NiSO4•6H2O, CH3（CH2）11OSO3Na and La2O3 as well as current density were separately 220g/L, 0.08g/L, 0.9g/L and 1.0 A/m2 under which the deposition rate reached 24.2μm/h. The established model had an agreement with the experimental values and can be used to predict the deposition rate within the experimental range. The experiment also showed that the deposition rate, structure and other physical properties of the Ni coating prepared with addition of La2O3(0.9g/L) were greatly improved compared with the sample prepared without addition of La2O3 under same conditions.

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Stacking apertures and estimation strategies for reflection and diffraction enhancement

Geophysics ◽

10.1190/geo2015-0525.1 ◽

2016 ◽

Vol 81 (4) ◽

pp. V271-V282 ◽

Cited By ~ 15

Author(s):

Jorge H. Faccipieri ◽

Tiago A. Coimbra ◽

Leiv-J. Gelius ◽

Martin Tygel

Keyword(s):

Fresnel Zone ◽

Careful Selection ◽

Time Migration ◽

Key Factor ◽

Common Reflection Surface ◽

Good Potential ◽

Image Quality Improvement ◽

The Common ◽

Selection Of

It is well known that the quality of stacking results (e.g., noise reduction, event enhancement, and continuity) can be greatly influenced not only by the traveltime operator chosen but also by the apertures used. We have considered two so-called diffraction-stack traveltimes, together with the corresponding apertures, designed to enhance reflections and diffractions, respectively. The first one is the common-reflection-surface (CRS) diffraction traveltime that is obtained from the general CRS traveltime upon the condition that the target reflector reduced to a point, which we refer to as the diffraction CRS (DCRS) traveltime. The second one is the double-square-root (DSR) traveltime, well established in time migration. We have observed that the DCRS and DSR traveltimes depend on fewer parameters (two in 2D and five in 3D) than the full CRS traveltime (three in 2D and eight in 3D). For the DCRS and DSR traveltimes, we have proposed specific apertures based on the projected Fresnel zone, which are able to produce high-quality stacked sections using less parameters to be estimated. The key factor in that approach lies in the choice of traveltime operators together with careful selection of stacking apertures. In particular, suitable choices of operators and apertures lead to stacking volumes in which reflections are enhanced (and the diffractions are attenuated) or the corresponding ones in which diffractions are enhanced (and reflections are attenuated). Synthetic and field data confirm the proposed approach has good potential for image-quality improvement.

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