Seismic Loss Mechanisms

Geophysics ◽  
1981 ◽  
Vol 46 (5) ◽  
pp. 806-808 ◽  
Author(s):  
N. C. Dutta
Keyword(s):  
Wave Attenuation ◽  
Dynamic Properties ◽  
Petroleum Industry ◽  
Seismic Energy ◽  
Seismic Wave Attenuation ◽  
Seismic Loss ◽  
Research Workshop ◽  
Rock Specimens ◽  
Made In ◽  
Loss Mechanisms

In the petroleum industry there is considerable current interest in understanding the causes of seismic energy loss. During the past few years, considerable progress has been made in the field of seismic wave attenuation as a result of both controlled laboratory studies of the static and the dynamic properties of rock specimens and theoretical modeling. During the 49th Annual International Meeting of the Society of Exploration Geophysicists in New Orleans, a research workshop on Seismic Loss Mechanisms was organized. The purpose of this workshop was to assess current understanding of the physical processes that cause attenuation of seismic energy. The workshop, organized by Kenneth Larner of Western Geophysical and the author, featured a multispeaker format involving invited papers from both industry and academia. The presentations were followed by discussions lasting approximately 90 minutes which included the speakers, the audience, and a panel of experts in the field of seismology.

Experimental evidence for the Biot‐Gardner theory

Geophysics ◽  
1989 ◽  
Vol 54 (4) ◽  
pp. 524-527 ◽  
Author(s):  
R. Mörig ◽  
H. Burkhardt
Keyword(s):  
Experimental Evidence ◽  
Seismic Wave ◽  
Seismic Data ◽  
Seismic Waves ◽  
Wave Attenuation ◽  
Wide Spectrum ◽  
Seismic Energy ◽  
Porous Rocks ◽  
Saturation State ◽  
Seismic Wave Attenuation

Seismic wave attenuation has been a subject of interest during the last 40 years because it may be of use in interpreting seismic data. From this attenuation parameter, more detailed information about the lithology of the subsurface may be deduced if we understand the absorption mechanisms by which dissipation of seismic energy is governed. We are, therefore, studying in the laboratory the effects of different parameters such as porosity, permeability, pore fluid, and saturation state on the absorption of seismic waves in porous rocks over a wide spectrum ranging from seismic to ultrasonic frequencies (Burkhardt et al., 1986).

scholarly journals Focus Energy Determination of Mining Microseisms Using Residual Seismic Wave Attenuation in Deep Coal Mining

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Mingwei Zhang ◽  
Shengdong Liu ◽  
Shuzhao Chen ◽  
Yanlong Chen ◽  
Guang Xu ◽  
...  
Keyword(s):  
Wave Attenuation ◽  
Seismic Energy ◽  
Computation Method ◽  
Seismic Wave Attenuation ◽  
Effective Components ◽  
Great Homogeneity ◽  
Deep Rock ◽  
The Impact ◽  
Energy Computation

Based on the energy attenuation characteristics of residual wave in deep rock, a method was developed to determine the microseismic focus energy. Differential energy loss in infinitesimal spreading distance is logically deduced, upon which energy attenuation equation was established. With a logarithmic transformation, a linear relation of the residual seismic energy with distance is formulated. Its intercept was used to determine the microseismic focus energy. The result is compared with that determined by the energy density method. The reliability of the determined focus energy and the impact of the built-in velocity threshold on the residual wave energy computation are discussed. Meanwhile, the energy absorption coefficient used for representing the absorption characteristics of the rock medium in the mining region under study is also clarified. Key findings show that the microseismic focus energy confirmed by the residual wave attenuation is reliable. The result’s accuracy is quite high, especially for the events in deep rock with great homogeneity. The developed focus energy computation method is closely dependent on the integrity of waveform, accuracy of repositioning, and reliability of effective components extraction. The new method has been shown to be effective and practical.

scholarly journals Numerical modeling of wave processes in fractured porous fluid-saturated media

2018 ◽  
pp. 130-149
Author(s):  
М.А. Новиков ◽  
В.В. Лисица ◽  
А.А. Козяев
Keyword(s):  
Wave Attenuation ◽  
Fluid Flows ◽  
Seismic Energy ◽  
Finite Difference Approximation ◽  
Difference Approximation ◽  
Seismic Wave Attenuation ◽  
Saturated Media ◽  
Biot’S Equations ◽  
Geological Formations ◽  
Hydrodynamic Permeability

Одной из актуальных задач современной прикладной геофизики является выделение характерных признаков наличия развитой трещиноватости в пласте по сейсмическим данным. Более того, необходимо выделять флюидозаполненные системы трещин, образующих связанную систему трещин, способную обеспечивать достаточную гидродинамическую проницаемость резервуара. В настоящей статье представлен численный алгоритм расчета волновых полей в трещиноватых пороупругих средах, основанный на конечно-разностной аппроксимации уравнений Био. На основе численных экспериментов показано, что связность трещин, т.е. наличие систем пересекающихся трещин, существенно повышает поглощение сейсмической энергии, что обусловлено возникновением локальных потоков флюида внутри трещин. Приводится детальный частотный анализ затухания сейсмических волн и обусловленной этим дисперсии. One of important problems in modern applied geophysics is to distinguish the specific indications of developed fractures in geological formations using seismic data. In addition, it is necessary to distinguish the fluid-saturated systems of cracks capable of providing a sufficient hydrodynamic permeability of reservoirs. In this paper we propose a numerical algorithm to study wave fields in fractured porous fluid-saturated media on the basis of a finite-difference approximation of Biot's equations. Our numerical results show that the intersecting fractures significantly increase the absorption of seismic energy due to the appearance of fluid flows in cracks. A detailed frequency analysis of seismic wave attenuation is given.

Caveats and Pitfalls of Production Forecast Uncertainty Analysis Using Design of Experiments

2021 ◽  
Author(s):  
Boxiao Li ◽  
Hemant Phale ◽  
Yanfen Zhang ◽  
Timothy Tokar ◽  
Xian-Huan Wen
Keyword(s):  
Design Of Experiments ◽  
Uncertainty Analysis ◽  
History Matching ◽  
Petroleum Industry ◽  
Production Forecast ◽  
Forecast Uncertainty ◽  
Field Development ◽  
Development Alternatives ◽  
Modeling Principles ◽  
Made In

Abstract Design of Experiments (DoE) is one of the most commonly employed techniques in the petroleum industry for Assisted History Matching (AHM) and uncertainty analysis of reservoir production forecasts. Although conceptually straightforward, DoE is often misused by practitioners because many of its statistical and modeling principles are not carefully followed. Our earlier paper (Li et al. 2019) detailed the best practices in DoE-based AHM for brownfields. However, to our best knowledge, there is a lack of studies that summarize the common caveats and pitfalls in DoE-based production forecast uncertainty analysis for greenfields and history-matched brownfields. Our objective here is to summarize these caveats and pitfalls to help practitioners apply the correct principles for DoE-based production forecast uncertainty analysis. Over 60 common pitfalls in all stages of a DoE workflow are summarized. Special attention is paid to the following critical project transitions: (1) the transition from static earth modeling to dynamic reservoir simulation; (2) from AHM to production forecast; and (3) from analyzing subsurface uncertainties to analyzing field-development alternatives. Most pitfalls can be avoided by consistently following the statistical and modeling principles. Some pitfalls, however, can trap experienced engineers. For example, mistakes made in handling the three abovementioned transitions can yield strongly unreliable proxy and sensitivity analysis. For the representative examples we study, they can lead to having a proxy R2 of less than 0.2 versus larger than 0.9 if done correctly. Two improved experimental designs are created to resolve this challenge. Besides the technical pitfalls that are avoidable via robust statistical workflows, we also highlight the often more severe non-technical pitfalls that cannot be evaluated by measures like R2. Thoughts are shared on how they can be avoided, especially during project framing and the three critical transition scenarios.

scholarly journals Forced oscillation measurements of seismic wave attenuation and stiffness moduli dispersion in glycerine‐saturated Berea sandstone

2018 ◽  
Vol 67 (4) ◽  
pp. 956-968 ◽  
Author(s):  
Samuel Chapman ◽  
Jan V. M. Borgomano ◽  
Hanjun Yin ◽  
Jerome Fortin ◽  
Beatriz Quintal
Keyword(s):  
Seismic Wave ◽  
Wave Attenuation ◽  
Forced Oscillation ◽  
Berea Sandstone ◽  
Seismic Wave Attenuation

scholarly journals ACOUSTIC SEISMIC WAVE ATTENUATION IN ROCKS: ESTIMATES INSTABILITIES, FREQUENCY-DEPENDENCE AND INCOHERENCES

2017 ◽  
Vol 35 (3) ◽  
Author(s):  
Julián David Peláez ◽  
Luis Alfredo Montes
Keyword(s):  
Frequency Shift ◽  
Seismic Wave ◽  
Wave Attenuation ◽  
Spectral Ratio ◽  
Well Logs ◽  
Well Log ◽  
Seismic Profiles ◽  
Seismic Wave Attenuation ◽  
Transmission Coefficients ◽  
Centroid Frequency

ABSTRACT. Seismic wave attenuation (Q−1) values indicate relevant media properties, such as fluid content and porosity. Q−1 estimates, obtained using both VSP and conventional well log data, did not exhibit comparable trends, nor values. Whereas VSP results represent total attenuation, well log Q−1, which, theoretically, should represent scattering losses, displayed a low percentage correlation with transmission coefficients and other well logs. The influence of processing routines, chosen methodology and input parameters on Q−1-values suggests that ASR (Amplitude Spectral Ratio) and CFS (Centroid Frequency Shift) attenuation estimates should be regarded, in practical terms, as relative quantities instead of absolute ones. Seemingly incoherent negative values are frequent, nonetheless these could hold a physical meaning related to elastic amplification at interfaces. Considering that quality factor (Q) values obtained were more unstable than Q−1-values, it is advisable to report the latter. Keywords: Vertical Seismic Profiles, well logs, transmission coefficients, scattering, amplification.RESUMO. Os valores de atenuação da onda sísmica (Q−1) indicam propriedades relavantes dos meios, tais como conteúdo de fluido e porosidade. As estimativas do Q−1, obtidas usando dados de VSP e dados de poços convencionais, não apresentaram tendências nem valores comparáveis. Enquanto os resultados de VSP representamatenuação total, os resultados dos dados de poços, que teoricamente deveriam representar perdas de dispersão, apresentaramuma baixa correlação percentual com os coeficientes de transmissão e outros dados de poços. A influência das rotinas de processamento, da metodologia escolhida e dos parâmetros de entrada nos valores Q−1 sugere que as estimativas de atenuação ASR (Amplitude Spectral Ratio) e CFS (Centroid Frequency Shift) devem ser, em termos práticos, consideradas como quantidades relativas em vez de absolutas. Valores negativos aparentemente incoerentes são frequentes, no entanto estes poderiam conter um significado físico relacionado `a amplificação elástica nas interfaces. Considerando que os valores do fator de qualidade (Q) obtidos foram mais instáveis do que os valores de Q−1, é aconselhável documentar o último. Palavras-chave: Perfis Sísmicos Verticais, registros de poços, coeficientes de transmissão, dispersão, amplificação.

scholarly journals Approach to Stochastic Modeling of Power Systems

2010 ◽  
Vol 26 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Alexander Rubtsov
Keyword(s):  
Power Systems ◽  
Power System ◽  
Stochastic Modeling ◽  
Transfer Functions ◽  
Dynamic Properties ◽  
Stochastic Disturbance ◽  
Modeling Power ◽  
Linearized Model ◽  
System Power ◽  
Made In

Approach to Stochastic Modeling of Power SystemsThis paper presents an approach to modeling power system that contains sources of stochastic disturbance. It is based on frequency analysis of linearized model of power system. Power system dynamic properties are accounted by equivalent transfer functions of machines and their control equipment. This will allow more accurate calculations for different analysis tasks. Methodology of system linearization is proposed and results of linearized model test are delivered.The research was made in frame of a project with funding participation of the European Commission.

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