scholarly journals Seismic wave attenuation and dispersion induced by fluid flow within various cracks and a small amount of bubbly fluid

2020 ◽  
Vol 63 (4) ◽  
Author(s):  
Yu Chen ◽  
Zhaoyun Zong ◽  
Chongpeng Huang ◽  
Shuan Zhang
Keyword(s):  
Fluid Flow ◽  
Seismic Wave ◽  
Wave Attenuation ◽  
Seismic Wave Attenuation ◽  
Bubbly Fluid ◽  
Attenuation And Dispersion

Seismic wave attenuation and dispersion due to wave-induced fluid flow in rocks with strong permeability fluctuations

2013 ◽  
Vol 134 (6) ◽  
pp. 4742-4751 ◽  
Author(s):  
J. Germán Rubino ◽  
Leonardo B. Monachesi ◽  
Tobias M. Müller ◽  
Luis Guarracino ◽  
Klaus Holliger
Keyword(s):  
Fluid Flow ◽  
Seismic Wave ◽  
Wave Attenuation ◽  
Seismic Wave Attenuation ◽  
Wave Induced ◽  
Attenuation And Dispersion

Seismic wave attenuation due to fluid pressure diffusion at the mesoscopic scale: an experimental and numerical study

2021 ◽  
Author(s):  
Samuel Chapman ◽  
Jan V. M. Borgomano ◽  
Beatriz Quintal ◽  
Sally M. Benson ◽  
Jerome Fortin
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Wave Attenuation ◽  
Fluid Pressure ◽  
Fluid Distribution ◽  
Mesoscopic Scale ◽  
Seismic Wave Attenuation ◽  
X Ray ◽  
Pressure Diffusion ◽  
Attenuation And Dispersion

<p>Monitoring of the subsurface with seismic methods can be improved by better understanding the attenuation of seismic waves due to fluid pressure diffusion (FPD). In porous rocks saturated with multiple fluid phases the attenuation of seismic waves by FPD is sensitive to the mesoscopic scale distribution of the respective fluids. The relationship between fluid distribution and seismic wave attenuation could be used, for example, to assess the effectiveness of residual trapping of carbon dioxide (CO2) in the subsurface. Determining such relationships requires validating models of FPD with accurate laboratory measurements of seismic wave attenuation and modulus dispersion over a broad frequency range, and, in addition, characterising the fluid distribution during experiments. To address this challenge, experiments were performed on a Berea sandstone sample in which the exsolution of CO2 from water in the pore space of the sample was induced by a reduction in pore pressure. The fluid distribution was determined with X-ray computed tomography (CT) in a first set of experiments. The CO2 exosolved predominantly near the outlet, resulting in a heterogeneous fluid distribution along the sample length. In a second set of experiments, at similar pressure and temperature conditions, the forced oscillation method was used to measure the attenuation and modulus dispersion in the partially saturated sample over a broad frequency range (0.1 - 1000 Hz). Significant P-wave attenuation and dispersion was observed, while S-wave attenuation and dispersion were negligible. These observations suggest that the dominant mechanism of attenuation and dispersion was FPD. The attenuation and dispersion by FPD was subsequently modelled by solving Biot’s quasi-static equations of poroelasticity with the finite element method. The fluid saturation distribution determined from the X-ray CT was used in combination with a Reuss average to define a single phase effective fluid bulk modulus. The numerical solutions agree well with the attenuation and modulus dispersion measured in the laboratory, supporting the interpretation that attenuation and dispersion was due to FPD occurring in the heterogenous distribution of the coexisting fluids. The numerical simulations have the advantage that the models can easily be improved by including sub-core scale porosity and permeability distributions, which can also be determined using X-ray CT. In the future this could allow for conducting experiments on heterogenous samples.</p>

scholarly journals NUMERICAL ALGORITHM OF SEISMIC ATTENUATION ESTIMATION IN ANISOTROPIC FRACTURED POROUS FLUID-SATURATED MEDIA

2021 ◽  
Vol 2 (2) ◽  
pp. 186-195
Author(s):  
Mikhail A. Novikov ◽  
Vadim V. Lisitsa
Keyword(s):  
Fluid Flow ◽  
Seismic Wave ◽  
Numerical Algorithm ◽  
Wave Attenuation ◽  
Seismic Attenuation ◽  
Staggered Grid ◽  
Filling Material ◽  
Seismic Wave Attenuation ◽  
Saturated Media ◽  
Wave Induced

In our work we investigate the effect of transport and elastic properties anisotropy on seismic attenuation due to fracture-to-fracture wave-induced fluid flow using numerical algorithm of estimation of seismic wave attenuation in anisotropic fractured porous fluid-saturated media. Algorithm is based on numerical solution of anisotropic Biot equations using finite-difference scheme on staggered grid. We perform a set of numerical experiments to model wave propagation in fractured media with anisotropic fractured-filling material providing wave-induced fluid flow within interconnected fractures. Recorded signals are used for numerical estimation of inverse quality factor. Results demonstrate the effect of fracture-filling material anisotropy on seismic wave attenuation.

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.

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