THE SEISMIC EXPRESSION OF THREE-DIMENSIONAL SANDBOX MODELS

1996 ◽  
Vol 36 (1) ◽  
pp. 490
Author(s):  
D.H. Sherlock ◽  
B.J. Evans ◽  
C.C. Ford
Keyword(s):  
Seismic Data ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Seismic Wave Propagation ◽  
Construction Time ◽  
Geological Structures ◽  
Seismic Modelling ◽  
Solid Models ◽  
First Time

Analogue sandbox models provide cheap, concise data and allow the evolution of geological structures to be observed under controlled conditions in a laboratory. Seismic physical modelling is used to study the effects of seismic wave propagation in isotropic and anisotropic media and to improve methods of data acquisition, processing and interpretation. These two independent geological modelling techniques have been linked for the first time, to combine and expand the existing benefits of each method.Seismic physical modelling to date has employed solid models, constructed with pre-determined structures built into the model. Previous attempts to adapt this technology to unconsolidated materials failed due to the severe energy attenuation of seismic waves in cohesionless grain matrices, and excessive signal scatter due to scaling limitations of the geological feature size to wavelength ratio. This paper presents our research to overcome these problems and thereby allow the successful seismic imaging of sandbox models.A number of techniques have been developed to combine these two independent modelling methods and results show that it is possible to image several layers within the models, demonstrating the potential to interpret complex geological structures within such models. For seismic modelling, the main advantages are that the seismic data collected from these models contain natural variation that cannot be built into solid models, which results in a more realistic image, and the cost and construction time of the models are also dramatically reduced. For sandbox modelling, the recording of seismic data over them allows far more detailed interpretation of the structures than previously possible and also allows direct comparison with field data for the first time, to substantiate or negate an existing interpretation.

Reconstruction of the Reservoir Fine Structure by Using Scattering Attributes

2021 ◽  
Author(s):  
Vladimir Cheverda ◽  
Vadim Lisitsa ◽  
Maksim Protasov ◽  
Galina Reshetova ◽  
Andrey Ledyaev ◽  
...  
Keyword(s):  
Seismic Data ◽  
Numerical Experiments ◽  
Seismic Waves ◽  
Fractured Reservoirs ◽  
Three Dimensional ◽  
Geological Structure ◽  
Discrete Elements ◽  
Digital Twin ◽  
The North ◽  
Slip Surfaces

Abstract To develop the optimal strategy for developing a hydrocarbon field, one should know in fine detail its geological structure. More and more attention has been paid to cavernous-fractured reservoirs within the carbonate environment in the last decades. This article presents a technology for three-dimensional computing images of such reservoirs using scattered seismic waves. To verify it, we built a particular synthetic model, a digital twin of one of the licensed objects in the north of Eastern Siberia. One distinctive feature of this digital twin is the representation of faults not as some ideal slip surfaces but as three-dimensional geological bodies filled with tectonic breccias. To simulate such breccias and the geometry of these bodies, we performed a series of numerical experiments based on the discrete elements technique. The purpose of these experiments is the simulation of the geomechanical processes of fault formation. For the digital twin constructed, we performed full-scale 3D seismic modeling, which made it possible to conduct fully controlled numerical experiments on the construction of wave images and, on this basis, to propose an optimal seismic data processing graph.

scholarly journals EARTHQUAKES MAGNITUDE AS THE INDICATOR OF THE TECTONOSPHERE PHYSICOMECHANICAL PARAMETERS (to the 80 Anniversary of the Prominent Georgian Seismologist and Geophysicist Leah Ivanovna Tuliani)

2017 ◽  
Author(s):  
Л.Э. Левин
Keyword(s):  
Seismic Waves ◽  
Quantitative Characteristic ◽  
Three Dimensional ◽  
Tien Shan ◽  
Japanese Island ◽  
Empirical Determination ◽  
Original Procedure ◽  
Lithosphere Thickness ◽  
First Time

В статье приведены в сжатом виде результаты исследований, касающиеся строения литосферы Кавказского региона. Приведена оригинальная методика определения мощности литосферы по распределению энергии сейсмических волн с глубиной. Описана впервые выявленная особенность строения орогенов Большого и Малого Кавказа, где мощность литосферы оказалась меньше мощности коры. Приведено определение пространственного распространения т.н. астенолинз – зон частичного плавления в коре орогенов Большого и Малого Кавказа, являющихся очагами орогенного вулканизма. Подобные астенолинзы были также выявлены в коре орогенов Японской островной дуги и Тянь-Шаня и, таким образом, была установлена глобальная особенность строения многих постколлизионных орогенов. Приведены основные положения по эмпирическому определению квадратичной зависимости энергии сейсмических волн от магнитуды и количественной характеристики термодинамических параметров очага землетрясения и др. Results of studies, which are concerned the Caucasian region lithosphere structure are given in the compressed form. The original procedure of the lithosphere thickness determination from the energy distribution of seismic waves with the depth is given. The first time revealed special feature of the large and small Caucasus orogens structure is described, where the lithosphere thickness proved to be less than the thickness of crust. The three-dimensional propagation determination of the so-called astenolenses – zones of partial melting in the crust of the large and small Caucasus orogens, which are the centers of orogenic volcanism is given. Similar astenolenses were also revealed in the orogens crust of Japanese island arc and Tien Shan and was, thus, established the global special feature of the structure of many postkollision orogens. Basic provision of the quadratic dependence of seismic waves energy on the magnitude empirical determination and the quantitative characteristic of the thermodynamic parameters of the seismic center and others are given.

EVOLUTION OF SEISMIC TECHNOLOGY INTO THE 1980's

1980 ◽  
Vol 20 (1) ◽  
pp. 110 ◽  
Author(s):  
R.J. Graebner ◽  
G. Steel and. C.B. Wason
Keyword(s):  
Seismic Data ◽  
Three Dimensional ◽  
Seismic Wave Propagation ◽  
Image Resolution ◽  
Accurate Estimation ◽  
Computer Performance ◽  
Field Development ◽  
Borehole Logs ◽  
Processing Techniques ◽  
Hydrocarbon Reserves

In the last few years, the quality and resolution of subsurface images, based on seismic data, have improved considerably with the introduction of wavelet processing and three-dimensional (3D) seismic techniques. Together, these are being used increasingly in field development to optimize drilling locations and improve estimates of hydrocarbon reserves.Exploiting the steady gains in computer performance, significant enhancement in image resolution is being achieved using the convolutional model of seismic wave propagation. In the 1980's, progress will proceed apace along this path, one which is analogous to the photographic imaging technique; furthermore the wavelet processing techniques will continue to improve, aided by better imaging methods based on holographic principles.Another innovation that will offer the potential for a more accurate estimation of hydrocarbon reserves is the application of inversion by modelling. These methods generate estimates of the subsurface lithologic parameters directly from the data. The results are reconciled with available borehole logs and used to define reservoir characteristics at the spatial sampling of the data.

Seismic expression of carbonate build-up karstification: karst modelling strategies and insights from synthetic seismic

2020 ◽  
pp. SP509-2019-124
Author(s):  
Arnaud Fournillon ◽  
François Fournier ◽  
Olivier Vidal
Keyword(s):  
Seismic Data ◽  
Three Dimensional ◽  
Acoustic Properties ◽  
Acoustic Model ◽  
Borehole Data ◽  
Seismic Modelling ◽  
Stratigraphic Architecture ◽  
Modelling Strategies ◽  
Karst Systems ◽  
Very High

AbstractMany ancient carbonate build-ups are impacted by meteoric diagenetic processes, including karstification. However, very little is known about the acoustic properties and seismic expression of karstified reservoirs. This paper investigates potential seismic expressions of karstified build-ups by means of synthetic seismic modelling. The overall stratigraphic architecture and physical properties of rock are derived from published examples of SE Asian carbonate build-ups. Various karst systems, corresponding to distinct stages of karstification of varying intensity, have been superimposed to the background facies-related acoustic model. Three-dimensional synthetic seismic cubes have been computed from the karst-bearing acoustic model and by testing various wavelet frequencies. The proposed approach allowed several types of palaeokarst to be reproduced, from dendritic karst and flank-margin caves to cave networks, in amplitude sections. However, geometrical seismic attributes, like coherency, cannot be accurately reproduced with modelling based on the available literature. In addition, the exploration of this synthetic seismic data shows that non-stratiform diagenetic bodies (i.e. leached carbonate wedges in a mixing zone) appear as stratiform even in very-high-resolution seismic. Thus, their detection and characterization require advanced techniques or prior knowledge, such as borehole data.

A COMPARISON OF PHYSICAL MODEL WITH FIELD DATA OVER OLIVER FIELD, VULCAN GRABEN

1995 ◽  
Vol 35 (1) ◽  
pp. 26 ◽  
Author(s):  
B.J. Evans ◽  
B.F. Oke ◽  
M. Urosevic ◽  
K. Chakraborty
Keyword(s):  
Physical Model ◽  
Seismic Data ◽  
Field Data ◽  
Joint Venture ◽  
Survey Design ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Field Work ◽  
Physical Models ◽  
2D And 3D

Physical models representing the three dimensional geology of oil fields can be built from materials such as plastics and resins. Using ultrasound transmitters and receivers, 2D and 3D seismic surveys can be simulated to aid in the survey design of field work, provide insight into data processing, and can test interpretation concepts. Such modelling simulates most aspects of both land and marine seismic.In 1993 BHP Petroleum, on behalf of the AC/P6 Joint Venture, contracted Curtin University's Geophysics Group to build a 1:40,000 scale, 11-layer, 2.5D model of the Oliver Field so that 2D and 3D field data acquisition and processing could be simulated. A 2.5D model is invariant in the strike direction, but can answer most of the questions of a true 3D model at a fraction of the effort and cost. This was the first such model built in Australia, and one of the most complex physical models ever built.Of interest was the quality of imaging under the fault shadow near reservoir level, and whether the application of dip or strike 3D acquisition and processing approaches could improve the seismic data quality. Consequently, both dip (2D) and strike (2.5D) seismic data were acquired over the model using similar parameters to those used in conventional offshore acquisition. The data were processed to migration stage and compared with the field seismic data. Numerical model and field VSP data were also processed and compared with the field and physical model seismic data.The good agreement between processed physical model seismic and field seismic shows that physical modelling of geology has application in both two and three dimensional interpretation, acquisition planning, and processing testing and optimisation.This physical model experiment proved conclusively that shallow faults with a relatively large velocity contrast across them cause 'back' faults on the seismic data which do not exist in reality. Furthermore, this experiment proved for the first time using a physical model that strike 3D marine recording is preferable to dip 3D marine recording.

Investigating the seismic imaging of faults using PS data from the Snøhvit field, Barents Sea, and forward seismic modelling 

2021 ◽  
Author(s):  
Jennifer Cunningham ◽  
Wiktor Weibull ◽  
Nestor Cardozo ◽  
David Iacopini
Keyword(s):  
Fault Zone ◽  
Seismic Data ◽  
Seismic Waves ◽  
Barents Sea ◽  
Incidence Angle ◽  
Seismic Signal ◽  
Fault Zones ◽  
Seismic Modelling ◽  
Systematic Improvement

<p>PS seismic data from the Snøhvit field are compared with forward seismic modelling to understand the effect of azimuthal separation and incidence angle on the imaging of faults. Two faults, one oriented oblique to the survey and one approximately parallel to the survey were chosen. Azimuthally separated W (source is W relative to receivers) and E (source E relative to receivers) data demonstrate that fault imaging is more affected by azimuth when the faults are oblique to the survey orientation, and W data image the faults better. Partial stack data show that with increasing incidence angle there is a systematic improvement in the quality of fault imaging in both the E and W data. In addition, the frequency content of seismic waves back-scattered from within and around fault zones is analysed in the Snøhvit data. Low-medium frequencies are dominant within fault zones, compared with higher frequencies in adjacent areas and haloes of medium frequencies surrounding the faults. Two synthetic experiments support the azimuth, incidence angle and frequency observations. In the first experiment, the fault is modelled as a planar discontinuity and the data were processed in the same way as the Snøhvit data (into separate azimuths and incidence angle stacks). The first experiment confirms a strengthening in the seismic signal from faults in the W data. This is due to the interaction of specular waves and diffractions which are more abundant in the W data. The second experiment had three parts modelling the fault zone with different layering complexity. It proved that frequencies in the fault and adjacent areas increase with fault zone complexity, and that the internal architecture of faults can impact the frequencies in the data adjacent to faults. </p>

scholarly journals A Preconditioned 3-D Multi-Region Fast Multipole Solver for Seismic Wave Propagation in Complex Geometries

2012 ◽  
Vol 11 (2) ◽  
pp. 594-609 ◽  
Author(s):  
S. Chaillat ◽  
J.F. Semblat ◽  
M. Bonnet
Keyword(s):  
Wave Propagation ◽  
Seismic Wave ◽  
Seismic Waves ◽  
Plane Waves ◽  
Seismic Wave Propagation ◽  
Boundary Element Methods ◽  
Complex Geometries ◽  
Fast Multipole ◽  
Geological Structures ◽  
Actual Configuration

AbstractThe analysis of seismic wave propagation and amplification in complex geological structures requires efficient numerical methods. In this article, following up on recent studies devoted to the formulation, implementation and evaluation of 3-D single- and multi-region elastodynamic fast multipole boundary element methods (FM-BEMs), a simple preconditioning strategy is proposed. Its efficiency is demonstrated on both the single- and multi-region versions using benchmark examples (scattering of plane waves by canyons and basins). Finally, the preconditioned FM-BEM is applied to the scattering of plane seismic waves in an actual configuration (alpine basin of Grenoble, France), for which the high velocity contrast is seen to significantly affect the overall efficiency of the multi-region FM-BEM.

scholarly journals Seismic Design of Offshore Structures under Simplified Pulse-Like Earthquakes

CivilEng ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 310-325
Author(s):  
Foteini Konstandakopoulou ◽  
George Papagiannopoulos ◽  
Nikos Pnevmatikos ◽  
Konstantinos Evangelinos ◽  
Ioannis Nikolaou ◽  
...  
Keyword(s):  
Seismic Waves ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Offshore Structures ◽  
Offshore Platforms ◽  
Inelastic Behavior ◽  
Global Response ◽  
Wind Actions ◽  
Near Fault Earthquakes ◽  
First Time

Oil and gas offshore structures are essential infrastructures which are subjected to several categories of environmental loads such as wave and wind actions. These loads commonly designate the structural design of offshore platforms. Additionally, several offshore platforms are founded in earthquake-prone areas and the design of them is intensely affected by seismic ground motions. To be sure, various investigations have studied the earthquake response of offshore structures under the action of far-field seismic events. However, the inelastic behavior of platforms under the action of simple pulses has not been examined yet, where the latter loads can successfully simulate near-fault earthquakes. This work investigates, for the first time to our knowledge, the dynamic inelastic response of offshore platforms subjected to triangular, exponential, sinusoidal, and rectangular pulses. Thus, three-dimensional offshore structures are examined also considering the dynamic soil-pile-platform interaction effects, satisfying all the pertinent provisions of European Codes and taking into account geometric and material nonlinearities as well as the effects of the different angles of incidence of seismic waves on the overall/global response of offshore platforms.

scholarly journals Visualization of three dimensional earth fissures in geological structure

2015 ◽  
Vol 372 ◽  
pp. 227-229
Author(s):  
L. Zhu ◽  
J. Yu ◽  
Y. Liu ◽  
H. Gong ◽  
Y. Chen ◽  
...  
Keyword(s):  
Seismic Data ◽  
Three Dimensional ◽  
Geological Structure ◽  
Triangular Prism ◽  
Structure Model ◽  
Geological Structures ◽  
Ground Fissures ◽  
Earth Fissures ◽  
The Earth ◽  
Cutting Operation

Abstract. This paper proposes a new method for visualizing the earth fissures of geological structure in three dimensional (3-D) domains on the basis of the seismic data and features information of earth fissures. The seismic data were interpreted for obtaining the stratagraphic data with various lithological information and the depth of the earth fissures. The spatial distribution of the ground fissures including the dip, strike and width were digitalized on an ArcGIS platform. Firstly, the 3-D geological structure was rebuilt using the Generalized Tri-Prism (GTP) method which is a real solid method for displaying geological structures. The GTP method can reflect the inner material of the strata and can simulate complicated geological structures such as faults and stratagraphic pinch outs. The upper and lower surfaces of each stratum consist of Triangle Irregular Networks (TIN). The inner solid between the two surfaces are a series of triangular prisms. Secondly, since the width of the ground fissure gradually decreases with depth, multiple edge lines of the earth fissures on the bottom stratum surface are deduced on the basis of the fissure characteristics. Then, the model of the earth fissures consisting of a series of triangular pyramids can be constructed using these points and the edge lines. A cutting operation was carried out on the 3-D geological structure using this ground fissures model. If the surfaces of the ground fissures model intersects with the GTPs in the geological structure model, new GTPs were generated within the local regions. During this process, the topological relations between TIN, triangular prism and lines were reconstructed so that the visualization of ground fissures in the geological structure model is realized. This method can facilitate the mechanism for studying fissures and avoid the gaps between the fissure solid and the geological structure to accurately reflect their 3-D characteristics.

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