scholarly journals On Including Near-surface Zone Anisotropy for Static Corrections Computation—Polish Carpathians 3D Seismic Processing Case Study

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 66
Author(s):  
Mateusz Zaręba ◽  
Tomasz Danek ◽  
Jerzy Zając
Keyword(s):  
Seismic Data ◽  
Three Dimensional ◽  
Seismic Signal ◽  
Surface Zone ◽  
3D Seismic ◽  
Near Surface ◽  
Seismic Surveys ◽  
Geological Interpretation ◽  
Geological Conditions ◽  
Static Corrections

Obtaining the most accurate and detailed subsurface information from seismic surveys is one of the main challenges for seismic data processing, especially in the context of complex geological conditions (e.g., mountainous areas). The correct calculation of static corrections allows for the reliable processing of seismic data. This, in turn, leads to better geological interpretation. A seismic signal passing through a near-surface zone (NSZ) is adversely affected by the high heterogeneity of this zone. As a result of this, observed travel times often show anisotropy. The application of refractive waves and the time delay solution without taking into account the effects caused by the complex anisotropy of an NSZ does not meet the standards of modern seismic surveys. The construction of the NSZ model in mountain regions with the use of refraction may be extremely difficult, as the vertical layers can be observed very close to the surface. It is not sufficient to apply regular isotropic refractive solutions in such conditions. The presented studies show the results of taking into account the anisotropy of an NSZ in the calculations of static corrections. The presented results show that this step is critical for the detailed processing of three-dimensional (3D) seismic data collected in the difficult region of the Carpathians in Southern Poland.

scholarly journals USE OF A SATELLITE GEODESIC NETWORK IN THE QUASIGEOID MODEL

2021 ◽  
Vol 21 ◽  
pp. 15-23
Author(s):  
E.V. An ◽  
◽  
S.А. Istekova ◽  
Kh.M. Kassymkanova ◽  
G.K. Jangulova ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Ore Deposits ◽  
Seismic Exploration ◽  
3D Seismic ◽  
Tectonic Structure ◽  
High Quality ◽  
Seismic Surveys ◽  
Tectonic Faults ◽  
Geological Conditions

The article deals with the possibility of using seismic exploration in solving problems of ore geology in complex mining and geological conditions of Kazakhstan. The substantiation and characterization of geological and geophysical conditions for conducting experimental 3D seismic surveys at the deposits of the Zhilandinsky group of copper sandstones located in the Karaganda region of Central Kazakhstan are presented. The tasks are defined and the technique of conducting high-resolution 3D seismic exploration is developed, accompanied by modern processing and interpretation complexes for obtaining high-quality seismic materials for solving geological problems: studying the structural and tectonic structure of ore areas, identifying and refining ore-controlling structures, detecting and deep mapping of tectonic faults, volumetric mapping of intrusive massifs. The directions and technology of the process of modeling ore horizons and tracing them in space based on the results of a comprehensive interpretation of three-dimensional seismic exploration and geological and geophysical data, which will significantly increase the reliability coefficient of forecasting ore deposits, are indicated.

Imaging the near surface using velocity inversions of ultra-high-density 3D seismic data

2021 ◽  
Vol 40 (8) ◽  
pp. 584-589
Author(s):  
Tim Dean ◽  
Margarita Pavlova ◽  
Matthew Grant ◽  
Martin Bayly ◽  
Denis Sweeney ◽  
...  
Keyword(s):  
Seismic Data ◽  
Coal Industry ◽  
High Density ◽  
Rock Properties ◽  
3D Seismic ◽  
Near Surface ◽  
Seismic Surveys ◽  
Weathered Layer ◽  
History Of ◽  
The Cost

Within the coal industry, there is a rich history of the use of the surface seismic method, principally for exploration and employing sparse 2D lines for broad resource delineation and structural modeling. However, the acquisition of 3D seismic surveys adjacent to open-cut mines (from which the majority of coal is extracted) for superior resource definition ahead of their expansion has been explored only recently. Although the reflection results are extremely useful and enable the mapping of faults with sub-5 m throws, there is still interest in determining if the seismic data can be used to image both structures and rock properties in the near surface. In addition to mapping near-surface structures that have geotechnical implications, the ability to map the overburden properties (which can be quite heterogeneous) is desired. Before mining activities can take place, the overburden needs to be removed. The cost of the removal method employed is directly affected by the depth of the weathered layer and rock properties. In particular, hardness can vary significantly. In this paper, we demonstrate how high-density seismic data originally acquired for reflection processing can be processed to generate high-resolution velocity (both VS and VP) depth volumes, which enable the successful identification of shallow structures and the creation of highly detailed near-surface rock-property volumes.

Simultaneous estimation of residual static and crossdip corrections

Geophysics ◽  
1979 ◽  
Vol 44 (7) ◽  
pp. 1175-1192 ◽  
Author(s):  
Kenneth L. Larner ◽  
Bruce R. Gibson ◽  
Ron Chambers ◽  
Ralph A. Wiggins
Keyword(s):  
Three Dimensional ◽  
Synthetic Data ◽  
Simultaneous Estimation ◽  
Broad Line ◽  
Near Surface ◽  
Seismic Surveys ◽  
Surface Reflection ◽  
Static Corrections ◽  
Solution Parameters

Seismic surveys on land are frequently conducted along nonlinear survey lines. Familiar examples include crooked lines controlled by existing road networks or by surface typography, lines that are otherwise linear but along which shotpoints occasionally must be offset laterally, and intentionally designed three‐dimensional (3-D) or broad‐line surveys. Departures from linear profiles introduce an element of complexity—crossdip—into the problem of estimating residual near‐surface reflection static time corrections (statics). Crossdip is the component of dip normal to the local profile direction. We have incorporated the effect of crossdip into the system of simultaneous equations that model residual static anomalies. The observed traveltimes of all reflections selected for analysis are represented as linear combinations of source and receiver static anomalies, structural shapes, residual normal moveouts, and crossdip terms. The static time components are taken to be surface‐consistent and independent of reflecting horizon, whereas the other solution parameters are subsurface‐consistent and pertain to specific horizons. Unfortunately, the inclusion of crossdip in the equations increases the degree of nonuniqueness of residual statics solutions. Its inclusion, however, is a necessity wherever horizons having differing crossdips are analyzed simultaneously. Such simultaneous analysis often is the best means for upgrading the reliability of the crosscorrelation estimates (i.e., the traveltime observations) upon which all statics are based. Synthetic‐data examples demonstrate the degree to which crossdip estimates and statics estimates can be separated from one another. Although estimates of crossdips are a useful by‐product, the accuracy of the static corrections is considered of prime importance. When critical crossdip terms are ignored in a statics solution, the quality of the common‐depthpoint (CDP) stacks suffer, as shown in comparison processings of field sections. Moreover, crossdip estimates from 3-D or broad‐line surveys are questionable if crossdip and static corrections are not considered in a unified solution.

scholarly journals Modern Geodetic Measurement Techniques in Gravimetric Studies on the Example of Gypsum Karst in the Siesławice Region

2018 ◽  
Vol 35 ◽  
pp. 03002 ◽  
Author(s):  
Sławomir Porzucek ◽  
Monika Łój ◽  
Karolina Matwij ◽  
Wojciech Matwij
Keyword(s):  
Laser Scanning ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
Field Studies ◽  
Surface Zone ◽  
Three Dimensional Model ◽  
Geodetic Measurement ◽  
Near Surface ◽  
Gypsum Karst

In the region of Siesławice (near Busko-Zdrój, Poland) there are unique phenomena of gypsum karst. Atmospheric factors caused numerous gypsum outcrops, canals and underground voids. The article presents the possibility of using non-invasive gravimetric surveys supplemented with geodetic measurements to illustrate karst changes occurring around the void. The use of modern geodetic measurement techniques including terrestrial and airborne laser scanning enables to generate a digital terrain model and a three-dimensional model of voids. Gravimetric field studies allowed to map the anomalies of the gravitational field of the near-surface zone. Geodetic measurement results have made it possible to accurately determine the terrain correction that supplemented the gravimetric anomaly information. Geophysical interpretation indicate the presence of weathered rocks in the near surface zone and fractures and loosened zones located surround the karst cave.

Design and Implementation of VSP Seismic Data Acquisition System Based on Virtual Instrument Technology

2011 ◽  
Vol 135-136 ◽  
pp. 375-379
Author(s):  
Nai Quan Sun ◽  
Yong Mei Yang ◽  
Rui Jing Dong
Keyword(s):  
Data Acquisition ◽  
Virtual Instrument ◽  
Seismic Data ◽  
Data Acquisition System ◽  
Seismic Signal ◽  
Acquisition System ◽  
Near Surface ◽  
Testing Tool ◽  
Instrument Technology ◽  
Seismic Data Acquisition

Near earth surface can be seen as viscoelastic medium. It’s important to collect VSP seismic signal in near-surface.This paper proposed plan designed for VSP seismic data acquisition system based on virtual instrument technology. This design applied the characteristic that the virtual instrument technology has strong capability in single processing and more abundant, distinct expression to VSP acquisition system. This design makes the acquisition system simple, expand easily. And it provides a practical and useful testing tool to logging exploration of near surface project.

Reprocessing legacy three-dimensional seismic data from the Halfmile Lake and Brunswick No. 6 volcanogenic massive sulphide deposits, New Brunswick, Canada

2019 ◽  
Vol 56 (5) ◽  
pp. 569-583 ◽  
Author(s):  
Gilles Bellefleur ◽  
Saeid Cheraghi ◽  
Alireza Malehmir
Keyword(s):  
New Brunswick ◽  
Seismic Data ◽  
Three Dimensional ◽  
Massive Sulphide ◽  
Seismic Survey ◽  
Deep Zone ◽  
3D Seismic ◽  
Massive Sulphide Deposits ◽  
Volcanogenic Massive Sulphide ◽  
Sulphide Deposits

We reprocessed legacy three-dimensional (3D) seismic data from the Halfmile Lake and Brunswick areas, both of which were acquired for mineral exploration in the Bathurst Mining Camp, New Brunswick. Each 3D seismic survey was acquired over known volcanogenic massive sulphide deposits and covered areas with strong mineral potential. Most improvements resulted from a reduction of coherent and random noise on prestack gathers and from an improved velocity model, combined with re-imaging with dip moveout corrections and poststack migration or prestack time migration. At Halfmile Lake, the new imaging results show the Deep zone and a possible extension of the sulphide mineralization at greater depth. True amplitude processing has shown that this anomaly has strong amplitudes and is offset from the Deep zone by a shallowly dipping fault (<15°). With the clearer geological context provided by our results, this anomaly, which appears as a stand-alone anomaly on an original image obtained by Noranda Exploration Ltd., becomes a defendable exploration target. Nonorthogonal acquisition geometry and receiver patches of the Brunswick No. 6 3D seismic survey generated artefacts after dip moveout processing that reduced the overall quality of the seismic volumes. By using a filtering approach based on the application of a weighted Laplacian-Gaussian filter in the Kx–Ky domain, we reduced the noise and improved the continuity of reflections. We also imaged the short and flat reflections observed previously only in the shallow part of prestack time migrated data. These short reflections appear as diffractions on the filtered stacked section with dip moveout corrections, indicating that they originate from small geological bodies or discontinuities in the subsurface.

scholarly journals Temporal and spatial variations in three-dimensional seismic oceanography

Ocean Science ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. 1053-1066
Author(s):  
Zheguang Zou ◽  
Parsa Bakhtiari Rad ◽  
Leonardo Macelloni ◽  
Likun Zhang
Keyword(s):  
Temporal Variation ◽  
Water Column ◽  
Seismic Data ◽  
Three Dimensional ◽  
Spatial Variations ◽  
Ocean Dynamics ◽  
3D Seismic ◽  
Temporal And Spatial Variations ◽  
Seismic Oceanography ◽  
Temporal And Spatial

Abstract. Seismic oceanography is a new cross-discipline between geophysics and oceanography that uses seismic reflection data to image and study the oceanic water column. Previous work on seismic oceanography was largely limited to two-dimensional (2D) seismic data and methods. Here we explore and quantify temporal and spatial variations in three-dimensional (3D) seismic oceanography to address whether 3D seismic imaging is meaningful in all directions and how one can take advantage of the variations. From a 3D multichannel seismic survey acquired for oil and gas exploration in the Gulf of Mexico over a 6-month period, a 3D oceanic seismic volume was derived. The 3D seismic images exhibit both temporal and spatial variations of the ocean, and theoretical and data analyses were used to quantify their contribution. Our results suggest that temporal variation is more prominent in the crossline direction than in the inline direction, causing discontinuities in crossline images. However, a series of 3D inline images can be seen as snapshots of the water column at different times, capturing temporal variation of thermohaline structures induced by ocean dynamics. Our findings suggest the potential uses of marine 3D seismic data in studying time-evolving mesoscale ocean dynamics.

scholarly journals Time-lapse difference static correction using prestack crosscorrelations: 4D seismic image enhancement case from Ketzin

Geophysics ◽  
2014 ◽  
Vol 79 (6) ◽  
pp. B243-B252 ◽  
Author(s):  
Peter Bergmann ◽  
Artem Kashubin ◽  
Monika Ivandic ◽  
Stefan Lüth ◽  
Christopher Juhlin
Keyword(s):  
Seismic Data ◽  
Time Lapse ◽  
Data Sets ◽  
Storage Site ◽  
Data Set ◽  
Near Surface ◽  
Static Correction ◽  
Seismic Image ◽  
Static Corrections ◽  
4D Seismic

A method for static correction of time-lapse differences in reflection arrival times of time-lapse prestack seismic data is presented. These arrival-time differences are typically caused by changes in the near-surface velocities between the acquisitions and had a detrimental impact on time-lapse seismic imaging. Trace-to-trace time shifts of the data sets from different vintages are determined by crosscorrelations. The time shifts are decomposed in a surface-consistent manner, which yields static corrections that tie the repeat data to the baseline data. Hence, this approach implies that new refraction static corrections for the repeat data sets are unnecessary. The approach is demonstrated on a 4D seismic data set from the Ketzin [Formula: see text] pilot storage site, Germany, and is compared with the result of an initial processing that was based on separate refraction static corrections. It is shown that the time-lapse difference static correction approach reduces 4D noise more effectively than separate refraction static corrections and is significantly less labor intensive.

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