Comparison of various technologies of near-surface section impact studies during seismic exploration in permafrost formations.

2006 ◽  
Author(s):  
Vladislav Ivanovich Kuznetsov
Keyword(s):  
Seismic Exploration ◽  
Near Surface ◽  
Impact Studies ◽  
Surface Section

scholarly journals Specificity of the seismic material obtained in complex seismo geological conditions (swamp zone)

2019 ◽  
Author(s):  
А.А. Левицкий ◽  
А.В. Рудаков ◽  
М.С. Левицкая
Keyword(s):  
Negative Impact ◽  
Seismic Source ◽  
Integrated Approach ◽  
Seismic Exploration ◽  
Near Surface ◽  
Factors Affecting ◽  
Geological Conditions ◽  
Seismic Recording ◽  
Surface Section

Основная цель работы – описание новых технических и методологических средств, используемых АО «Южморгеология» при проведении полевых сейсморазведочных работ МОГТ 3D в лиманно-плавневых зонах Славянского района Краснодарского края в 2014-2015 гг. Представлены основные результаты опытных работ, обоснован выбор параметров съемки и их влияние на качество сейсмической записи: заглубление пневмоисточников BOLT 2200LL-BHS, количество накоплений возбуждения и необходимая глубина погружения датчиков регистраторов. В качестве датчиков регистраторов использовались маршфоны «СВГ-6», которые задавливались с помощью металлического шеста с креплением на конце на глубину 1,0–2,5 м до достижения уверенного контакта с твердой поверхностью (плотный грунт, глинистая подошва), снижая негативное влияние шумов (микросейсм) от корневой системы камышей (рис. 2А, В). Группирование «СВГ-6» шестью последовательно соединенными геофонами (GS-20DX) увеличило чувствительность датчика к слабым сигналам, возбуждаемым, в слабо консолидированной толще, а его прочная конструкция и металлическая проушина, позволила извлекать маршфон из скважины, полностью заполненной водой и шламом.  Приведены основные свойства верхней части разреза (ВЧР) исследуемой площади по данным бурения с кратким описанием литологической характеристика разреза до глубины 10 м. Показаны сейсмограммы, полученные на одном участке в разных сейсмогеологических условиях. Выявлена зависимость распределения значений среднеквадратичных амплитуд и доминантных частот по площади от поверхностных условий возбуждения и приема колебаний. Данная зависимость также прослеживается на предварительных временных разрезах. Были проанализированы основные факторы, влияющие на качество получаемого сейсмического материала. На основе проведенного исследования авторами обосновывается необходимость использования комплексного подхода к анализу качества сейсмических данных при работах в сложных сейсмогеологических условиях. В качестве вывода приведены основные рекомендации к проведению сейсморазведочных работ в лиманно-плавневых зонах. The main objective of the work is the description of new technical and methodological tools used by Yuzhmorgeologiya JSC when conducting CDP 3D field seismic surveys in the estuaries of the Slavyansk district of the Krasnodar Region in 2014-2015. The main results of the experimental work are presented; the choice of survey parameters and their impact on the quality of the seismic recording is validated: digging-in of the seismic source points BOLT 2200LL-BHS, the number of excitation accumulations and the required depth of recorder sensors. Geophones “SVG-6” were used as sensors of the recorders, which were crushed with a metal pole with a fastening at the end to a depth of 1.0–2.5 m until steady contact with a solid surface (dense soil, clay base) was achieved, reducing the negative impact noise (microseism) from the root system of reeds (Fig. 2A, B). Grouping the SVG-6 with six consecutive geophones (GS-20DX) increased the sensitivity of the equipment to weak signals being excited in a weakly consolidated layer, and its robust design and metal eye, made it possible to extract the geophone from a well completely filled with water and sludge. The basic properties of the upper part of the section (near-surface section) of the studied area are given according to the drilling data with a brief description of the lithological characteristics of the section to a depth of 10 m. Seismograms obtained at one site in different seismic and geological conditions are shown. The dependence of the distribution of values of root-mean-square amplitudes and dominant frequencies over the area on the surface conditions of excitation and reception of vibrations is revealed. This dependence is also observed in the preliminary time sections. The main factors affecting the quality of the obtained seismic material were analyzed. Based on the present study, the authors validate the need for the use of an integrated approach to analyzing the quality of seismic data when working under complex seismic and geological conditions. As a conclusion, the main recommendations for seismic exploration in the estuaries are presented.

ANALYSIS AND IMPROVEMENT OF SEISMIC EXPLORATION METHODS IN EASTERN SIBERIA

2021 ◽  
pp. 56-73
Author(s):  
A. S. Еfimov ◽  
◽  
E. V. Mosyagin ◽  
Keyword(s):  
Information Content ◽  
Complex Salt ◽  
Middle Part ◽  
Thin Layers ◽  
Seismic Survey ◽  
Seismic Exploration ◽  
Eastern Siberia ◽  
Multiple Reflections ◽  
Near Surface ◽  
Surface Section

Many enterprises and authors have often addressed the problem of increasing the efficiency of seismic exploration (geological constructions and forecasting) at the prospecting stage in the Siberian Platform (SP) throughout the entire period of oil prospecting in Eastern Siberia. This is confirmed by numerous publications and production reports. Unfortunately, it should be admitted that there is still no cardinal progress in solving this problem. The reasons for the low information content of geophysical materials for the SP conditions in these publications are substantiated and set out in great detail. This is both a sharply dissected relief, and small-block models of the near-surface section, and an energy dissipation in rudaceous pyroclastic rocks of the Triassic, background of reverberation, near-surface waves formed by thin layers of traps in near-surface section, local velocity anomalies in the middle part of the section, background and interference of partially multiple reflections, complex salt tectonics, blocking and tesselation of secondary changes in Riphean rocks, forming tesselation of seismoacoustic properties. These are the main, in authors’ opinion, reasons reducing reliability of the geological section forecast based on seismic data. Some of them are removed using a complex of geophysical data. But tie, backbone on seismic horizons lies also at the heart of integration. Therefore, increasing the information content of seismic survey in regard to fixing the reflecting boundaries based on selection and substantiation, field observation systems and technologies is the most important issue in the problem under discussion.

Integrated Seismic Exploration for Open-Cut Mining: The Importance of the Near Surface

First Break ◽  
2021 ◽  
Vol 39 (8) ◽  
pp. 87-93
Author(s):  
Claudio Strobbia ◽  
Simone Re ◽  
Tim Dean ◽  
Matthew Grant ◽  
Martin Bayly ◽  
...  
Keyword(s):  
Seismic Exploration ◽  
Near Surface

Slant f-k transform of multichannel seismic surface wave data

Geophysics ◽  
2019 ◽  
Vol 84 (1) ◽  
pp. A19-A24 ◽  
Author(s):  
Aleksander S. Serdyukov ◽  
Aleksander V. Yablokov ◽  
Anton A. Duchkov ◽  
Anton A. Azarov ◽  
Valery D. Baranov
Keyword(s):  
Surface Wave ◽  
Seismic Data ◽  
Signal To Noise Ratio ◽  
Velocity Estimation ◽  
Seismic Exploration ◽  
Spectral Processing ◽  
Near Surface ◽  
Frequency Time Representation ◽  
Time Representation ◽  
S Transform

We have addressed the problem of estimating surface-wave phase velocities through the spectral processing of seismic data. This is the key step of the well-known near-surface seismic exploration method, called multichannel analysis of surface waves. To increase the accuracy and ensure the unambiguity of the selection of dispersion curves, we have developed a new version of the frequency-wavenumber ([Formula: see text]-[Formula: see text]) transform based on the S-transform. We obtain the frequency-time representation of seismic data. We analyze the obtained S-transform frequency-time representation in a slant-stacking manner but use a spatial Fourier transform instead of amplitude stacking. Finally, we build the [Formula: see text]-[Formula: see text] image by analyzing the spatial spectra for different steering values of the surface-wave group velocities. The time localization of the surface-wave packet at each frequency increases the signal-to-noise ratio because of an exclusion of noise in other time steps (which does not fall in the effective width of the corresponding wavelet). The new [Formula: see text]-[Formula: see text] transform, i.e., the slant [Formula: see text]-[Formula: see text] (SFK) transform, renders a better spectral analysis than the conventional [Formula: see text]-[Formula: see text] transform and yields more accurate phase-velocity estimation, which is critical for the surface-wave analysis. The advantages of the SFK transform have been confirmed by synthetic- and field-data processing.

Seismic mapping of on-shore sediments at Andøya, Norway, deposited prior to the North Atlantic rifting

2020 ◽  
Vol 8 (4) ◽  
pp. SQ105-SQ114
Author(s):  
Tor Arne Johansen ◽  
Bent Ole Ruud ◽  
Tormod Henningsen ◽  
Marco Brönner
Keyword(s):  
North Atlantic ◽  
Seismic Velocity ◽  
Traffic Noise ◽  
Seismic Exploration ◽  
Small Scale ◽  
Near Surface ◽  
The North ◽  
Seismic Surveying ◽  
The North Atlantic ◽  
Seismic Velocity Contrasts

Andøya is an island in the north of Norway. On its eastern side, it contains a local downfaulted basin of Mesozoic sediments sheltered from erosion during subsequent periods of Pleistocene glaciation. The sediments were deposited before the North Atlantic rifting and partly overlie weathered basement. We have recently carried out seismic surveying to better understand the geometry and seismic responses of the basin system. Extensive civil infrastructure and wet mire made the study area challenging for seismic exploration. We shot the survey lines at wet mire with detonating cord during winter when the mire was frozen. In the summer, we conducted seismic surveying along road shoulders with a small-scale vibrator. The seismic processing was particularly challenging due to the influence of traffic noise, heterogeneous near-surface conditions, and large seismic velocity contrasts. We interpreted the seismic lines in integration with other geophysical data and well logs to obtain a consistent and best possible seismic model of the basin. Our interpretation indicates a reorganization of the regional paleostress regime that took place during the continental breakup in the Eocene. In spite of severe obstacles for seismic surveying of the area, our results honor the robustness of the seismic method for subsurface imaging.

scholarly journals Converted‐wave seismic exploration: Applications

Geophysics ◽  
2003 ◽  
Vol 68 (1) ◽  
pp. 40-57 ◽  
Author(s):  
Robert R. Stewart ◽  
James E. Gaiser ◽  
R. James Brown ◽  
Don C. Lawton
Keyword(s):  
Seismic Waves ◽  
Seismic Exploration ◽  
Fracture Density ◽  
Converted Wave ◽  
P Waves ◽  
Near Surface ◽  
S Waves ◽  
Subsurface Fluid ◽  
Processing Techniques ◽  
Gas Bearing

Converted seismic waves (specifically, downgoing P‐waves that convert on reflection to upcoming S‐waves are increasingly being used to explore for subsurface targets. Rapid advancements in both land and marine multicomponent acquisition and processing techniques have led to numerous applications for P‐S surveys. Uses that have arisen include structural imaging (e.g., “seeing” through gas‐bearing sediments, improved fault definition, enhanced near‐surface resolution), lithologic estimation (e.g., sand versus shale content, porosity), anisotropy analysis (e.g., fracture density and orientation), subsurface fluid description, and reservoir monitoring. Further applications of P‐S data and analysis of other more complicated converted modes are developing.

Applying integrated seismic technology to complex foothill areas of foreland basins in China

2019 ◽  
Vol 38 (8) ◽  
pp. 597-603
Author(s):  
Yong Fang ◽  
Wenshan Luo ◽  
Xiaoxia Luo ◽  
Xukui Feng ◽  
Bo Zhao ◽  
...  
Keyword(s):  
Seismic Data ◽  
Model Building ◽  
New Technologies ◽  
High Density ◽  
Hydrocarbon Exploration ◽  
Western China ◽  
Seismic Exploration ◽  
Foreland Basins ◽  
Near Surface ◽  
True Surface

Due to complicated near-surface conditions, including large elevation changes and complex geologic structures, accurate imaging of subsurface structures for hydrocarbon exploration in the foreland basins of western China has been challenging for many years. After decades of research and fieldwork, we developed an effective seismic exploration workflow that uses the latest technologies from acquisition to imaging. They include 3D high-density and wide-azimuth (WAZ) acquisition, 3D true-surface tilted transverse isotropy (TTI) anisotropic prestack depth migration, and dual-detachment structural modeling and interpretation. To further reduce uncertainty in velocity model building and improve imaging quality, our geologists, geophysicists, and reservoir engineers worked closely through the exploration cycle (seismic acquisition, processing, and interpretation). This exploration model has been used successfully in hydrocarbon exploration of many complex foothill areas in western China. Three-dimensional WAZ high-density seismic surveys have been conducted over 40,000 km2 of the foreland basins, greatly improving the field seismic data quality. After application of 3D true-surface TTI anisotropic depth model building and imaging with integrated structural interpretation, new discoveries of hydrocarbon reservoirs have increased. The application of new technologies not only increased drilling success but also reduced depth well-tie errors between seismic data and wells.

Advances in surface-wave tomography for near-surface applications

2021 ◽  
Vol 40 (8) ◽  
pp. 567-575
Author(s):  
Myrto Papadopoulou ◽  
Farbod Khosro Anjom ◽  
Mohammad Karim Karimpour ◽  
Valentina Laura Socco
Keyword(s):  
Surface Wave ◽  
Wave Velocity ◽  
P Wave ◽  
Seismic Exploration ◽  
S Wave ◽  
Data Set ◽  
Near Surface ◽  
Processing Times ◽  
Spatial Coverage ◽  
Wave Tomography

Surface-wave (SW) tomography is a technique that has been widely used in the field of seismology. It can provide higher resolution relative to the classical multichannel SW processing and inversion schemes that are usually adopted for near-surface applications. Nevertheless, the method is rarely used in this context, mainly due to the long processing times needed to pick the dispersion curves as well as the inability of the two-station processing to discriminate between higher SW modes. To make it efficient and to retrieve pseudo-2D/3D S-wave velocity (VS) and P-wave velocity (VP) models in a fast and convenient way, we develop a fully data-driven two-station dispersion curve estimation, which achieves dense spatial coverage without the involvement of an operator. To handle higher SW modes, we apply a dedicated time-windowing algorithm to isolate and pick the different modes. A multimodal tomographic inversion is applied to estimate a VS model. The VS model is then converted to a VP model with the Poisson's ratio estimated through the wavelength-depth method. We apply the method to a 2D seismic exploration data set acquired at a mining site, where strong lateral heterogeneity is expected, and to a 3D pilot data set, recorded with state-of-the-art acquisition technology. We compare the results with the ones retrieved from classical multichannel analysis.

Sign in / Sign up

Export Citation Format

Share Document