Seismic Soundoff

2020 ◽  
Vol 39 (1) ◽  
pp. 72-72
Author(s):  
Andrew Geary
Keyword(s):  
Numerical Modeling ◽  
Fractured Reservoirs ◽  
Characteristic Method ◽  
Seismic Responses

The following is an excerpt from SEG's Seismic Soundoff podcast. In this episode, Igor Kvasov, engineering manager at Google and cofounder of SeismoTrack, joins host Andrew Geary to discuss his new book, Numerical Modeling of Seismic Responses from Fractured Reservoirs by the Grid-characteristic Method. This episode is sponsored by TGS. Listen to the full episode at https://seg.org/podcast/post/8688 .

Reviews

2021 ◽  
Vol 40 (2) ◽  
pp. 154-154
Author(s):  
Edward S. Krebes
Keyword(s):  
Numerical Modeling ◽  
Fractured Reservoirs ◽  
Characteristic Method ◽  
Seismic Responses

Numerical Modeling of Seismic Responses from Fractured Reservoirs by the Grid-characteristic Method, by Vladimir Leviant, Igor Kvasov, and Igor Petrov, ISBN 978-1-560-80366-9, SEG, 272 p.

Numerical modeling of seismic responses from fractured reservoirs in 4D monitoring. Part one: seismic responses from fractured reservoirs in carbonate and shale formations

Geophysics ◽  
2021 ◽  
pp. 1-93
Author(s):  
Vladimir Leviant ◽  
Naum Marmalevsky ◽  
Igor Kvasov ◽  
Polina Stognii ◽  
Igor Petrov
Keyword(s):  
Numerical Modeling ◽  
Oil And Gas ◽  
Fractured Reservoirs ◽  
Main Tool ◽  
Time Lapse ◽  
Single Fracture ◽  
Fractured Reservoir ◽  
Seismic Responses ◽  
Shale Formations ◽  
Fracture Opening

One of the most urgent problems of oil and gas reservoir monitoring is the assessment of fractured reservoir infill type – with fluid-filled, gas-filled or closed (no-reservoir situation) fractures, which is of significant value for time-lapse seismic technology. We used the grid-characteristic method (GCM) for numerical modeling of seismic responses from fractured periodic elasto-acoustic structures. We consider every single fracture individually (without using the effective medium approach), and set explicit boundary conditions on fracture surfaces. We assume realistic height-to-thickness ratios – fracture opening (aperture) – equaling 3 to 5 orders of magnitude. These techniques make our models as close to real fractured reservoirs as possible. Analyzing the simulated seismic responses, we solve the problem of assessing fractured reservoir infill type. As a result, previously unknown properties of seismic responses from fractured reservoirs were revealed. We use AVO as the main tool for the analysis of fracture infill type effect on the seismic response in three frequency ranges. Three out of four models exhibit a stable positive AVO gradient regardless of the rock type and frequency range. The analysis of linearized Zoeppritz equations confirms such AVO behavior. We proposed quantitative criteria (indicators) for recognition of a fracture infill type. Amplitude-frequency analysis is shown to expand the capabilities of infill type recognition. Thus, a method for determining fractured reservoir infill type is established for carbonate and shale formations, which could become the basis for a new direction in time-lapse technology.

scholarly journals Joint flow seismic inversion for characterizing fractured reservoirs: Theoretical approach and numerical modeling

2013 ◽  
Author(s):  
Peter K. Kang ◽  
Yingcai Zheng ◽  
Xinding Fang ◽  
Rafal Wojcik ◽  
Dennis McLaughlin ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Theoretical Approach ◽  
Fractured Reservoirs ◽  
Seismic Inversion

scholarly journals Numerical modeling of influence of ice formations under seismic impacts based on grid-characteristic method

2017 ◽  
Vol 112 ◽  
pp. 1497-1505 ◽  
Author(s):  
Polina Stognii ◽  
Dmitriy Petrov ◽  
Nikolay Khokhlov ◽  
Alena Favorskaya
Keyword(s):  
Numerical Modeling ◽  
Characteristic Method ◽  
Seismic Impacts

scholarly journals Physical and numerical modeling of tuning and diffraction in azimuthally anisotropic media

Geophysics ◽  
2000 ◽  
Vol 65 (5) ◽  
pp. 1613-1621 ◽  
Author(s):  
Richard L. Gibson ◽  
Stephen Theophanis ◽  
M. Nafi Toksöz
Keyword(s):  
Numerical Modeling ◽  
Fractured Reservoirs ◽  
Homogeneous Model ◽  
Azimuthal Anisotropy ◽  
P Wave ◽  
Orthorhombic Symmetry ◽  
Fractured Reservoir ◽  
Sh Wave ◽  
Wave Data ◽  
Ray Methods

Fractured reservoirs are an important target for exploration and production geophysics, and the azimuthal anisotropy often associated with these reservoirs can strongly influence seismic wave propagation. We created a physical model of a fractured reservoir to simulate some of these propagation effects. The reservoir is represented by a phenolite disk that is thin with respect to the elastic wavelengths in the experiment, creating model dimensions that are representative of realistic reservoirs. Phenolite is strongly anisotropic with orthorhombic symmetry, which suggests that azimuthal amplitude versus offset (AVO) effects should be obvious in data. We acquired both SH- and P-wave data in common‐offset gathers with a near offset and a far offset and found that although the SH-wave data show clear azimuthal variations in AVO, the P-wave signals show no apparent changes with azimuth. We then applied numerical modeling to analyze the data. Because ray methods cannot model diffractions from the disk edge, we first used a ray‐Born technique to simulate variations in waveforms associated with such scattering. The synthetic seismograms reproduced variations in the SH-wave waveforms accurately, though the amplitude contrast between acquisition azimuths was overestimated. Assuming a laterally homogeneous model, we then applied ray methods to simulate tuning effects in SH- and P-wave data and confirmed that in spite of the large contrasts in elastic properties, the tuning of the P-wave reflections from the thin disk changed so there was negligible contrast in AVO with azimuth. Models of field scale reservoirs showed that the same effects could be expected for field applications.

scholarly journals NUMERICAL MODELING OF THE PROCESS OF DETECTION OF KARST CAVITIES IN RAILWAY EMBANKMENTS BY A GRID-CHARACTERISTIC METHOD

2017 ◽  
Vol 9 (2) ◽  
pp. 215-220
Author(s):  
Vladimir S. Egiyan ◽  
◽  
Alena V. Favorskaya ◽  
Aram A. Mkrtchyan ◽  
Igor B. Petrov ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Characteristic Method

Power Density Distribution in Subsurface Fractures Due to an Energized Steel Well-casing Source

2019 ◽  
Vol 24 (2) ◽  
pp. 285-297
Author(s):  
G. Didem Beskardes ◽  
W. Anderson McAliley ◽  
Mohsen Ahmadian ◽  
David T. Chapman ◽  
Chester J. Weiss ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Contrast Agents ◽  
Power Density ◽  
Fractured Reservoirs ◽  
Current Source ◽  
Hydraulic Fractures ◽  
Distributed Sensors ◽  
Fracture Width ◽  
Dc Excitation ◽  
Subsurface Fractures

Robust in situ power harvesting underlies the realization of embedded wireless sensors for monitoring the physicochemical state of subsurface engineered structures and environments. The use of electromagnetic (EM) contrast agents in hydraulically fractured reservoirs, in coordination with completion design of wells, offers a way to transmit energy to remotely charge distributed sensors and interrogate fracture width, extent, and fracture-stage cross-communication. The quantification of available power in fracture networks due to energized steel-cased wells is crucial for such sensor designs; however, this has not been clarified via numerical modeling in the limit of Direct Current (DC). This paper presents a numerical modeling study to determine the EM characteristics of a subsurface system that is based on a highly instrumented field observatory. We use those realistic field scenarios incorporating geometry and material properties of contrast agents, the wellbore, and the surrounding geologic environment to estimate volumetric power density near the wellbore and within hydraulic fractures. The numerical modeling results indicate that the highest power densities are mainly focused around the wellbore excited by a point current source and the fracture boundary. Using DC excitation, the highest power density in the fracture is at the fracture tip. The relatively high-power density on the order of tens of mW/m 3 at the vicinity of the wellbore and at fracture tips suggests that remote charging of sensor devices may be readily possible. Simulation results also show that the region of the highest power density can be significantly increased when the EM source is located inside a conductive fracture, which may lead to a promising deployment strategy for embedded micro-sensors in geologic formations.

Numerical modeling of seismicity induced by fluid injection in naturally fractured reservoirs

Geophysics ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. WC167-WC180 ◽  
Author(s):  
Xueping Zhao ◽  
R. Paul Young
Keyword(s):  
Numerical Modeling ◽  
Fractured Reservoirs ◽  
Seismic Source ◽  
Microseismic Monitoring ◽  
Naturally Fractured Reservoirs ◽  
Natural Fracture ◽  
Hydraulic Fractures ◽  
Field Observations ◽  
Natural Fractures ◽  
Naturally Fractured

The interaction between hydraulic and natural fractures is of great interest for the energy resource industry because natural fractures can significantly influence the overall geometry and effectiveness of hydraulic fractures. Microseismic monitoring provides a unique tool to monitor the evolution of fracturing around the treated rock reservoir, and seismic source mechanisms can yield information about the nature of deformation. We performed a numerical modeling study using a 2D distinct-element particle flow code ([Formula: see text]) to simulate realistic conditions and increase understanding of fracturing mechanisms in naturally fractured reservoirs, through comparisons with results of the geometry of hydraulic fractures and seismic source information (locations, magnitudes, and mechanisms) from both laboratory experiments and field observations. A suite of numerical models with fully dynamic and hydromechanical coupling was used to examine the interaction between natural and induced fractures, the effect of orientation of a preexisting fracture, the influence of differential stress, and the relationship between the fluid front, fracture tip, and induced seismicity. The numerical results qualitatively agree with the laboratory and field observations, and suggest possible mechanics for new fracture development and their interaction with a natural fracture (e.g., a tectonic fault). Therefore, the tested model could help in investigating the potential extent of induced fracturing in naturally fractured reservoirs, and in interpreting microseismic monitoring results to assess the effectiveness of a hydraulic fracturing project.

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