scholarly journals Spectral-ratio tomography for seismic attenuation estimation

2021 ◽  
Vol 18 (3) ◽  
pp. 392-405
Author(s):  
Ziqi Jin ◽  
Ying Shi ◽  
Qiqi Ma ◽  
Deguang Tian ◽  
Qi'an Meng ◽  
...  
Keyword(s):  
Seismic Waves ◽  
Estimation Method ◽  
Synthetic Data ◽  
Spectral Ratio ◽  
Seismic Attenuation ◽  
Estimation Methods ◽  
Inversion Method ◽  
Target Layer ◽  
Reservoir Parameter ◽  
Attenuation Estimation

Abstract When measuring surface seismic data, an accurate attenuation estimation method is necessary to compensate for the energy loss and phase distortion of seismic waves, and is also beneficial for further quantitative amplitude analyses and reservoir parameter predictions. For conventional Q-estimation methods (such as the log spectral-ratio (LSR) method and attenuated traveltime tomography), accuracy may be affected by the differences between the overburden ray paths of two selected reflections (we call it the overburden effect). In this study, we design a more accurate Q-tomography method to estimate Q-values (both in the overburden and target layer simultaneously) without overburden assumptions. We address the overburden effect by using an inversion method, which allows us to separate attenuation effects from the overburden through the traveltime differences in the tomography grid cells. We test the method on synthetic data and prove its feasibility and effectiveness by applying it to field data.

Quantifying uncertainties in attenuation estimation at methane-hydrate-bearing zones using sonic waveform logs

Geophysics ◽  
2013 ◽  
Vol 78 (5) ◽  
pp. D339-D353 ◽  
Author(s):  
Hiroyuki Suzuki ◽  
Jun Matsushima
Keyword(s):  
Frequency Shift ◽  
Methane Hydrate ◽  
Seismic Attenuation ◽  
Estimation Methods ◽  
Ratio Method ◽  
Median Frequency ◽  
Waveform Data ◽  
Shift Method ◽  
Sonic Logging ◽  
Attenuation Estimation

Application of seismic attenuation estimation using sonic waveform data is limited because the estimation methods have not yet been fully developed. Although the median frequency shift method is considered to be effective and robust compared to the conventional spectral ratio method, we demonstrated that the median frequency shift methods strongly depend on reference data under lower signal-to-noise ratios. We modified an existing median frequency shift method not to depend on arbitrarily choosing a reference value and to quantify the uncertainties in attenuation estimation. Furthermore, we implied the optimum selection of receiver pairs used for more stable attenuation analysis. Our numerical experiments supported the advantage of the proposed method. Although our main findings by applying the proposed methods in methane hydrate-bearing sediments are almost consistent with past field sonic logging measurements, we find some differences in the magnitude of attenuation values compared to existing sonic attenuation measurements and discuss various possible factors. We believe that more stable and reliable attenuation results can lead to clarifying various factors affecting attenuation estimation, such as the effect of scattering, near-field effects, and source-coupling effects. Furthermore, we emphasized the importance of scattering effect caused by the heterogeneity of the formation and demonstrated the limitation of characterizing the 1D heterogeneity using the sonic logging data spatially sampled at 0.15 m to adequately estimate the effect of scattering attenuation.

Estimation of ultrasonic scattering attenuation in partially frozen brines using magnetic resonance images

Geophysics ◽  
2011 ◽  
Vol 76 (1) ◽  
pp. T13-T25 ◽  
Author(s):  
Jun Matsushima ◽  
Makoto Suzuki ◽  
Yoshibumi Kato ◽  
Shuichi Rokugawa
Keyword(s):  
Magnetic Resonance ◽  
Seismic Waves ◽  
Synthetic Data ◽  
Magnetic Resonance Images ◽  
Seismic Attenuation ◽  
Ultrasonic Scattering ◽  
Data Set ◽  
Scattering Attenuation ◽  
Apparent Diffusion ◽  
Solid Liquid

Seismic attenuation is not due entirely to intrinsic properties; a component due to scattering effects is included. Although different techniques have been used to experimentally investigate the attenuation of seismic waves, not so many laboratory measurements of attenuation have taken into account the effect of scattering attenuation. Herein, partially frozen brine as a solid-liquid coexistence system is used to investigate attenuation phenomena. We obtained a series of 2D apparent diffusion coefficient (ADC) maps of the ice-brine coexisting system using a diffusion-weighted magnetic resonance imaging (DW-MRI) technique at [Formula: see text], and found a strongly heterogeneous spatial distribution of unfrozen brine. From these maps, we constructed a synthetic seismic data set propagating through 2D media, and generated synthetic data with a second-order finite-difference scheme for the 2D acoustic wave equation. We estimated ultrasonic scattering attenuation in such systems by the centroid frequency shift method and by assuming that the quality factor ([Formula: see text]-value) is independent of frequency. The estimated scattering attenuation ranges from 0.015 to 0.05, corresponding to 10% to 30% of the total attenuation measured in laboratory experiments.

scholarly journals Biot's equations-based reservoir parameter inversion using deep neural networks

2021 ◽  
Vol 18 (6) ◽  
pp. 862-874
Author(s):  
Fansheng Xiong ◽  
Heng Yong ◽  
Hua Chen ◽  
Han Wang ◽  
Weidong Shen
Keyword(s):  
High Efficiency ◽  
Synthetic Data ◽  
Rock Physics ◽  
Seismic Attributes ◽  
Inversion Method ◽  
Reservoir Properties ◽  
Shear Moduli ◽  
Parameter Inversion ◽  
Reservoir Parameter ◽  
Biot’S Equations

Abstract Reservoir parameter inversion from seismic data is an important issue in rock physics. The traditional optimisation-based inversion method requires high computational expense, and the process exhibits subjectivity due to the nonuniqueness of generated solutions. This study proposes a deep neural network (DNN)-based approach as a new means to analyse the sensitivity of seismic attributes to basic rock-physics parameters and then realise fast parameter inversion. First, synthetic data of inputs (reservoir properties) and outputs (seismic attributes) are generated using Biot's equations. Then, a forward DNN model is trained to carry out a sensitivity analysis. One can in turn investigate the influence of each rock-physics parameter on the seismic attributes calculated by Biot's equations, and the method can also be used to estimate and evaluate the accuracy of parameter inversion. Finally, DNNs are applied to parameter inversion. Different scenarios are designed to study the inversion accuracy of porosity, bulk and shear moduli of a rock matrix considering that the input quantities are different. It is found that the inversion of porosity is relatively easy and accurate, while more information is needed to make the inversion more accurate for bulk and shear moduli. From the presented results, the new approach makes it possible to realise accurate and pointwise inverse modelling with high efficiency for actual data interpretation and analysis.

Estimating attenuation and the relative information content of amplitude and phase spectra

Geophysics ◽  
2007 ◽  
Vol 72 (1) ◽  
pp. R19-R27 ◽  
Author(s):  
James Rickett
Keyword(s):  
Phase Difference ◽  
Seismic Waves ◽  
Spectral Ratio ◽  
Seismic Attenuation ◽  
Ratio Method ◽  
Relative Uncertainty ◽  
Phase Information ◽  
Relative Information ◽  
The Difference ◽  
Phase Spectra

Seismic attenuation affects both the amplitude and phase of seismic waves. Algorithms to estimate attenuation are split among those that use amplitude information (e.g., spectral-ratio method), those that use phase information (e.g., rise-time method), and those that use a combination of both (e.g., time-domain algorithms). In this study, I explore the relative information provided by amplitude and phase spectra. To do this, I show how the difference in phase spectra between waveforms recorded at two depth levels can be used to estimate attenuation. This phase-difference method is analogous to the method of spectral ratios, but uses phase information rather than amplitude information. Under the simplifying assumption that the noise in both log-amplitude and phase spectra can be modeled as uncorrelated Gaussian random variables with equal variance, the posterior variances in the attenuation estimates from the spectral-ratio and phase-difference methods can be compared directly. It turns out that over typical seismic bandwidths and typical levels of attenuation, the relative uncertainty in estimates of attenuation from phase spectra is approximately twice the relative uncertainty in estimates of attenuation from log-amplitude spectra. Including phase and amplitude information simultaneously (as opposed to just amplitude information) reduces the relative uncertainty by only about 10% over seismic bandwidths. This reduction in uncertainty is not large, but may be significant depending on the sensitivity of the application.

Seismic anelastic attenuation estimation using prestack seismic gathers

Geophysics ◽  
2019 ◽  
Vol 84 (6) ◽  
pp. M37-M49
Author(s):  
Naihao Liu ◽  
Bo Zhang ◽  
Jinghuai Gao ◽  
Hao Wu ◽  
Shengjun Li
Keyword(s):  
Seismic Data ◽  
Seismic Waves ◽  
Synthetic Data ◽  
Spectral Ratio ◽  
Time Frequency ◽  
Anelastic Attenuation ◽  
Time Migration ◽  
Seismic Quality Factor ◽  
Zero Offset ◽  
Nmo Stretch

The seismic quality factor [Formula: see text] quantifies the anelastic attenuation of seismic waves in the subsurface and can be used in assisting reservoir characterization and as an indicator of hydrocarbons. Usually, the [Formula: see text]-factor is estimated by comparing the spectrum changes of vertical seismic profiles and poststack seismic data. However, seismic processing such as the normal moveout (NMO) stretch would distort the spectrum of the seismic data. Hence, we have estimated [Formula: see text] using prestack time migration gathers. To mitigate the NMO stretch effect, we compensate the NMO stretch of prestack seismic gathers in the time-frequency domain. Similar to the log spectral method, our method obtains the [Formula: see text] by measuring the log spectral ratio (LSR) of seismic events of the top and base of the reservoir at a zero-offset seismic trace. The LSR has a linear relationship with a new parameter [Formula: see text] by assuming that the source wavelet is a constant-phase wavelet. The parameters [Formula: see text] and LSR vary with the offset value (traveltime). We use the values of [Formula: see text] and LSR obtained from nonzero-offset seismic traces to simulate the values of [Formula: see text] and LSR at a zero-offset seismic trace. Finally, we obtain [Formula: see text] by applying the classic LSR method to the simulated [Formula: see text] and LSR. To demonstrate the validity and effectiveness of our method, we first apply it to noise-free and noisy synthetic data examples and then to real seismic data acquired over the Sichuan Basin, China. The synthetic and real seismic applications demonstrate the effectiveness of our method in highlighting high anelastic-attenuation zones.

Estimation of shear-wave interval attenuation from mode-converted data

Geophysics ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. D11-D19 ◽  
Author(s):  
Bharath Shekar ◽  
Ilya Tsvankin
Keyword(s):  
Shear Wave ◽  
Attenuation Coefficient ◽  
Reservoir Characterization ◽  
Wave Attenuation ◽  
Pure Shear ◽  
Synthetic Data ◽  
Spectral Ratio ◽  
Ratio Method ◽  
S Wave ◽  
Target Layer

Interval attenuation measurements provide valuable information for reservoir characterization and lithology discrimination. We extend the attenuation layer-stripping method of Behura and Tsvankin to mode-converted (PS) waves with the goal of estimating the S-wave interval attenuation coefficient. By identifying PP and PS events with shared ray segments and applying the [Formula: see text] method, we first perform kinematic construction of pure shear (SS) events in the target layer and overburden. Then, the modified spectral-ratio method is used to compute the effective shear-wave attenuation coefficient for the target reflection. Finally, application of the dynamic version of velocity-independent layer stripping to the constructed SS reflections yields the interval S-wave attenuation coefficient in the target layer. The attenuation coefficient estimated for a range of source-receiver offsets can be inverted for the interval attenuation parameters. The method is tested on multicomponent synthetic data generated with the anisotropic reflectivity method for layered VTI (transversely isotropic with a vertical symmetry axis) and orthorhombic media.

Seismic Attenuation Estimation Using an Enhanced Log Spectral Ratio Method

2022 ◽  
pp. 1-1
Author(s):  
Naihao Liu ◽  
Shengtao Wei ◽  
Yang Yang ◽  
Shengjun Li ◽  
Fengyuan Sun ◽  
...  
Keyword(s):  
Spectral Ratio ◽  
Seismic Attenuation ◽  
Ratio Method ◽  
Spectral Ratio Method ◽  
Attenuation Estimation

Seismic attenuation estimation using the modified log spectral ratio method

2018 ◽  
Vol 159 ◽  
pp. 386-394 ◽  
Author(s):  
Naihao Liu ◽  
Bo Zhang ◽  
Jinghuai Gao ◽  
Zhaoqi Gao ◽  
Shengjun Li
Keyword(s):  
Spectral Ratio ◽  
Seismic Attenuation ◽  
Ratio Method ◽  
Spectral Ratio Method ◽  
Attenuation Estimation

Using The Fully Modified M Method In Estimating The Effect Of Cultivated Area On Barley Production In Iraq For The Period 1970-2018

2020 ◽  
Vol 2020 (66) ◽  
pp. 101-110
Author(s):  
. Azhar Kadhim Jbarah ◽  
Prof Dr. Ahmed Shaker Mohammed
Keyword(s):  
Regression Model ◽  
Moving Average ◽  
Estimation Method ◽  
Estimation Methods ◽  
Autoregressive Moving Average ◽  
Moving Average Models ◽  
Error Terms ◽  
Relationship Of ◽  
The Relationship ◽  
Barley Crop

The research is concerned with estimating the effect of the cultivated area of barley crop on the production of that crop by estimating the regression model representing the relationship of these two variables. The results of the tests indicated that the time series of the response variable values is stationary and the series of values of the explanatory variable were nonstationary and that they were integrated of order one ( I(1) ), these tests also indicate that the random error terms are auto correlated and can be modeled according to the mixed autoregressive-moving average models ARMA(p,q), for these results we cannot use the classical estimation method to estimate our regression model, therefore, a fully modified M method was adopted, which is a robust estimation methods, The estimated results indicate a positive significant relation between the production of barley crop and cultivated area.

scholarly journals Comparative Analysis of Kinect-Based and Oculus-Based Gaze Region Estimation Methods in a Driving Simulator

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 26
Author(s):  
David González-Ortega ◽  
Francisco Javier Díaz-Pernas ◽  
Mario Martínez-Zarzuela ◽  
Míriam Antón-Rodríguez
Keyword(s):  
Virtual Reality ◽  
Comparative Analysis ◽  
Driving Simulator ◽  
Estimation Method ◽  
Estimation Methods ◽  
Gaze Estimation ◽  
Driving Simulators ◽  
Oculus Rift ◽  
Gaze Patterns ◽  
And Performance

Driver’s gaze information can be crucial in driving research because of its relation to driver attention. Particularly, the inclusion of gaze data in driving simulators broadens the scope of research studies as they can relate drivers’ gaze patterns to their features and performance. In this paper, we present two gaze region estimation modules integrated in a driving simulator. One uses the 3D Kinect device and another uses the virtual reality Oculus Rift device. The modules are able to detect the region, out of seven in which the driving scene was divided, where a driver is gazing at in every route processed frame. Four methods were implemented and compared for gaze estimation, which learn the relation between gaze displacement and head movement. Two are simpler and based on points that try to capture this relation and two are based on classifiers such as MLP and SVM. Experiments were carried out with 12 users that drove on the same scenario twice, each one with a different visualization display, first with a big screen and later with Oculus Rift. On the whole, Oculus Rift outperformed Kinect as the best hardware for gaze estimation. The Oculus-based gaze region estimation method with the highest performance achieved an accuracy of 97.94%. The information provided by the Oculus Rift module enriches the driving simulator data and makes it possible a multimodal driving performance analysis apart from the immersion and realism obtained with the virtual reality experience provided by Oculus.

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