Geophysical Prospecting最新文献

{"title":"Simultaneous inversion of four physical parameters of hydrate reservoir for high accuracy porosity estimation","authors":"Yuning Yan,&nbsp;Hongbing Li","doi":"10.1111/1365-2478.13615","DOIUrl":"https://doi.org/10.1111/1365-2478.13615","url":null,"abstract":"<p>Estimation of the porosity of a hydrate reservoir is essential for its exploration and development. However, the estimation accuracy was usually less certain in most previous studies that simply assumed that there is a linear relationship between the porosity and single-elastic wave velocities or other rock physical parameters, thus affecting the evaluation of the reserves. In the three-phase Biot-type equations that are fundamental to model a hydrate-bearing reservoir, porosity, alongside hydrate saturation, mineral constituent proportions and hydrate–grain contact factor, is non-linearly responded by density, compressional and shear wave velocities. To improve porosity estimation, we propose to invert simultaneously four-parameter (porosity, hydrate saturation, mineral constituent proportions and hydrate–grain contact factor) using an iteratively nonlinear interior-point optimization algorithm to solve a nonlinear objective function that is a summation of the squared misfits between the well log and three-phase Biot-type equation–modelled density, compressional and shear wave velocities. A test in Mount Elbert gas hydrate research well was conducted for the case of a gas hydrate stratigraphic test well where elastic wave velocities, density, porosity and mineral composition analysis data are available. The four-parameter inversion yielded a lower root mean square error for porosity (0.0245) across the entire well-logging section compared to previous estimations from the linear relationship, post-stacked and pre-stacked seismic traces as well as the pore-filling effective medium theory model applied to other well cases. Additionally, the other three parameters demonstrated good agreement with well logs. Inversion tests conducted at three additional hydrate sites also produced accurate results. Consequently, the new method surpasses previous approaches in porosity estimation accuracy.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3202-3216"},"PeriodicalIF":1.8,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142429036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A mollifier approach to seismic data representation","authors":"F. P. L. Strijbos","doi":"10.1111/1365-2478.13613","DOIUrl":"https://doi.org/10.1111/1365-2478.13613","url":null,"abstract":"<p>The extension of the seismic bandwidth to lower frequencies enhances impedance contrasts that can be poorly represented by the broadband acquisition wavelet. Furthermore, long filters that are used to shape the wavelet of processed data can cause issues with noise, phase and interference between seismic events. In this paper, we use a mathematical technique known as mollification to resolve impedance variations with the highest detail allowed by the bandwidth of the data. The mollifier is integrated and windowed to match the low-frequency content of the data to yield a convenient conversion to relative impedance. Synthetic data created from wedge models show that the windowed mollifier provides an improved representation of the impedance profile. This is replicated by application to an acoustic well log and a regular seismic dataset recorded in the Southern North Sea as well as a broadband dataset recorded in the North Sea.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3217-3229"},"PeriodicalIF":1.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142429138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytic solutions for effective elastic moduli of isotropic solids containing oblate spheroid pores with critical porosity","authors":"Zhaoyun Zong,&nbsp;Fubin Chen,&nbsp;Xingyao Yin,&nbsp;Reza Rezaee,&nbsp;Théo Le Gallais","doi":"10.1111/1365-2478.13608","DOIUrl":"https://doi.org/10.1111/1365-2478.13608","url":null,"abstract":"&lt;p&gt;Accurate characterization for effective elastic moduli of porous solids is crucial for better understanding their mechanical behaviour and wave propagation, which has found many applications in the fields of engineering, rock physics and exploration geophysics. We choose the spheroids with different aspect ratios to describe the various pore geometries in porous solids. The approximate equations for compressibility and shear compliance of spheroid pores and differential effective medium theory constrained by critical porosity are used to derive the asymptotic solutions for effective elastic moduli of the solids containing randomly oriented spheroids. The critical porosity in the new asymptotic solutions can be flexibly adjusted according to the elastic moduli – porosity relation of a real solid, thus extending the application of classic David-Zimmerman model because it simply assumes the critical porosity is one. The asymptotic solutions are valid for the solids containing crack-like oblate spheroids with aspect ratio &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;annotation&gt;$alpha $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;&lt; 0.3, nearly spherical pores (0.7 &lt; &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;annotation&gt;$alpha $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;&lt; 1.3) and needle-like prolate pores with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;annotation&gt;$alpha $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; &gt; 3, instead of just valid in the limiting cases, for example perfectly spherical pores (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;annotation&gt;$alpha $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;= 1) and infinite thin cracks (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mo&gt;→&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$alpha to $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;0). The modelling results also show that the accuracies of asymptotic solutions are weakly affected by the critical porosity &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ϕ&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{phi }_{mathrm{c}}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and grain Poisson's ratio &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;v&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{v}_0}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, although the elastic moduli have appreciable dependency of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ϕ&lt;/mi&gt;\u0000 &lt;mi&gt;c&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{phi }_{mathrm{c}}}$&lt;/anno","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3230-3246"},"PeriodicalIF":1.8,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An novel finite difference dispersion error elimination mechanism in the Lax–Wendroff high-order time discretization","authors":"Wenquan Liang,&nbsp;Yanfei Wang","doi":"10.1111/1365-2478.13611","DOIUrl":"https://doi.org/10.1111/1365-2478.13611","url":null,"abstract":"<p>Time domain finite difference methods have been widely used for wave-equation modelling in exploration geophysics over many decades. When using time domain finite difference methods, it is desirable to use a larger time step so as to save numerical simulation time. The Lax–Wendroff method is one of the well-known methods to allow larger time step without increasing the time grid dispersion. However, the Lax–Wendroff method suffers from more time consumption because there are more spatial derivatives required to be approximated by the finite difference operators. We propose a new finite difference scheme for the Lax–Wendroff method so as to reduce the numerical simulation time. Then we determine the finite difference operator coefficients and analyse the dispersion error of the proposed finite difference scheme for the Lax–Wendroff method. At last, we apply the proposed finite difference scheme for the Lax–Wendroff method to different velocity models. The numerical simulation results indicate that the proposed finite difference scheme for the Lax–Wendroff method can effectively suppress time grid dispersion and is more efficient compared to the traditional finite difference scheme for the Lax–Wendroff method.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3247-3257"},"PeriodicalIF":1.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An efficient pseudoelastic pure P-mode wave equation and the implementation of the free surface boundary condition","authors":"Xinru Mu,&nbsp;Tariq Alkhalifah","doi":"10.1111/1365-2478.13610","DOIUrl":"https://doi.org/10.1111/1365-2478.13610","url":null,"abstract":"<p>Based on the elastic wave equation, a pseudoelastic pure P-mode wave equation has been recently derived by projecting the wavefield along the wavefront normal direction. This pseudoelastic pure P-mode wave equation offers an accurate simulation of P-wave fields with accurate elastic phase and amplitude characteristics. Moreover, considering no S-waves are involved, it is computationally more efficient than the elastic wave equation, making it an excellent choice as a forward simulation engine for P-wave exploration. Here, we propose a new pseudoelastic pure P-mode wave equation and apply the stress image method to it to implement the free surface boundary condition. The new pseudoelastic wave equation offers significantly improved computational efficiency compared to the previous pseudoelastic wave equation. Additionally, the wavefields simulated by this new pseudoelastic wave equation exhibit clear physical interpretations. We evaluate the accuracy of the new wave equation in simulating elastic P-waves by employing a model with high-velocity contrasts. We find that this new equation, which purely admits P-waves, though having exact amplitude and phase behaviour as the elastic waves for transmission components, the amplitudes slightly suffer in the scattering scenario. The difference in amplitude between the elastic and our pseudoelastic increases as the contrast in velocity at the interface (interlayer velocity ratio) increases, especially the S-wave velocities. This has negative implications on scattering from the free surface boundary condition or the sea bottom interface, especially if the shear wave velocity below the surface or the sea bottom is high. However, in cases where, like for land data in the Middle East, the transition to a free surface is smoother, the accuracy of the pseudoelastic equation is high. In all cases, regardless of the interlayer velocity ratio, the accuracy of the pseudoelastic wave equation in simulating the elastic case, for scattered waves, exceeds that of the acoustic wave equation in phase and amplitude.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3187-3201"},"PeriodicalIF":1.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cross-equalization for time-lapse sparker seismic data","authors":"Soojin Lee,&nbsp;Jongpil Won,&nbsp;Hyunggu Jun","doi":"10.1111/1365-2478.13600","DOIUrl":"https://doi.org/10.1111/1365-2478.13600","url":null,"abstract":"<p>Time-lapse seismic data processing is an important technique for observing subsurface changes over time. The conventional time-lapse seismic exploration has been conducted using a large-scale exploration system. However, for efficient monitoring of shallow subsurface, time-lapse monitoring based on the small-scale exploration system is required. Small-scale exploration system using a sparker source offers high vertical resolution and cost efficiency, but it faces challenges, such as inconsistent waveforms of sparker sources, inaccurate positioning information and a low signal-to-noise ratio. Therefore, this study proposes a data processing workflow to preserve the signal and enhance the repeatability of small-scale time-lapse seismic data acquired using a sparker source. The proposed workflow has three stages: pre-stack, post-stack and machine learning–based data processing. Conventional seismic data processing methods were applied to enhance the quality of the sparker seismic data during the pre-stack data processing stage. In the post-stack processing stage, the positions and energy correction were performed, and the machine learning–based data processing stage attenuated random noise and applied a matched filter. The data processing was performed using only the seismic signals recorded near the seafloor, and the results confirmed the improvement in the repeatability of the entire seismic profile, including that of the target area. According to the repeatability quantification results, the predictability increased and the normalized root mean square decreased during data processing, indicating improved repeatability. In particular, the repeatability of the data was greatly improved through vertical correction, energy correction and matched filtering approaches. The processing results demonstrate that the data processing method proposed in this study can effectively enhance the repeatability of high-resolution time-lapse seismic data. Consequently, this approach could contribute to a more accurate understanding of temporal changes in subsurface structure and material properties.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3258-3279"},"PeriodicalIF":1.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1365-2478.13600","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate identification of salt domes using deep learning techniques: Transformers, generative artificial intelligence and liquid state machines","authors":"Kamal Souadih,&nbsp;Anis Mohammedi,&nbsp;Sofia Chergui","doi":"10.1111/1365-2478.13603","DOIUrl":"10.1111/1365-2478.13603","url":null,"abstract":"<p>Across various global regions abundant in oil and natural gas reserves, the presence of substantial sub-surface salt deposits holds significant relevance. Accurate identification of salt domes becomes crucial for enterprises engaged in oil and gas exploration. Our research introduces a precise method for the automatic detection of salt domes, leveraging advanced deep learning architectures such as U-net, transformers, artificial intelligence generative models and liquid state machines. In comparison with state-of-the-art techniques, our model demonstrates superior performance, achieving a stable and validated <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>96</mn>\u0000 <mo>%</mo>\u0000 </mrow>\u0000 <annotation>$96%$</annotation>\u0000 </semantics></math> intersection over the union metric, indicating high accuracy and robustness. Furthermore, the Dice similarity coefficient attaining <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>90</mn>\u0000 <mo>%</mo>\u0000 </mrow>\u0000 <annotation>$90%$</annotation>\u0000 </semantics></math> underscores the model's proficiency in closely aligning with ground truth across diverse scenarios. This evaluation, conducted on 1000 seismic images, reveals that our proposed architecture is not only comparable but often surpasses existing segmentation models in effectiveness and reliability.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3280-3294"},"PeriodicalIF":1.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An improved affine mixed-grid method for frequency-domain finite-difference elastic modelling","authors":"Shu-Li Dong,&nbsp;Jing-Bo Chen","doi":"10.1111/1365-2478.13596","DOIUrl":"https://doi.org/10.1111/1365-2478.13596","url":null,"abstract":"<p>In seismic frequency-domain finite-difference modelling, the affine mixed-grid method effectively eliminates the spatial sampling restriction associated with square meshes of the rotated mixed-grid method. Nevertheless, the affine mixed-grid method makes a weighted average of the entire elastic wave equations, resulting in reduced accuracy compared to the average-derivative method in the case of rectangular meshes. It is worth noting, however, that the average-derivative method is presently inapplicable to free-surface scenarios, whereas the affine mixed-grid method is applicable. By performing weighted averages of the derivative terms instead of the entire elastic wave equations in Cartesian and affine rotated coordinate systems, we have developed an improved affine mixed-grid method for elastic-wave frequency-domain finite-difference modelling. The proposed improved affine mixed-grid method 9-point scheme overcomes the drawback that the accuracy of affine mixed-grid method is lower than that of average-derivative method for unequal directional grid intervals. Moreover, the improved affine mixed-grid method 6-point scheme provides much higher numerical accuracy than the affine mixed-grid method 6-point scheme at either equal or unequal directional grid intervals. On the other hand, the proposed improved affine mixed-grid method simplifies the coding complexity for implementing free-surface condition in elastic-wave frequency-domain finite-difference modelling by modifying the elastic parameters of the free-surface layer and thus constructing the impedance matrix containing the free-surface condition directly.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3295-3315"},"PeriodicalIF":1.8,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of rock mass permeability using relaxation time and P-wave velocity","authors":"Zhicheng Song,&nbsp;Lichao Nie,&nbsp;Zhiqiang Li,&nbsp;Shilei Zhang,&nbsp;Zhaoyang Deng,&nbsp;Yuancheng Li","doi":"10.1111/1365-2478.13602","DOIUrl":"10.1111/1365-2478.13602","url":null,"abstract":"<p>Due to the inherent unpredictability of geological conditions, tunnelling operations are often at risk of encountering water inrushes. Such incidents can lead to construction delays, impose financial strains and pose significant safety threats to the workers involved. Water-bearing geological formations are the main triggers for such incidents, with factors such as the positioning, water quantity and permeability distribution of these formations being key to predicting the occurrence and severity of water inrush disasters. By leveraging the complex interplay among relaxation time, P-wave velocity and permeability within the rock's physical properties, a series of indoor tests were conducted on 40 artificial reef limestone cores to extract the necessary parameters. Through the analysis of the data, the comprehensive permeability prediction model was established, and the correlation coefficient was 0.9420 between the model's predictions and actual measurements. At the same time, through theoretical and mechanism analysis, the relationship between permeability and relaxation time and the relationship between permeability and P-wave velocity were analysed. Finally, 10 natural reef limestone samples were used to verify the accuracy of the model. The prediction model enables an accurate evaluation of tunnel permeability, thus providing a scientific basis for the mitigation of tunnel water inrush hazards.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3371-3380"},"PeriodicalIF":1.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laboratory measurements of water saturation effects on the acoustic velocity and attenuation of sand packs in the 1–20 kHz frequency range","authors":"Hanif S. Sutiyoso,&nbsp;Sourav K. Sahoo,&nbsp;Laurence J. North,&nbsp;Timothy A. Minshull,&nbsp;Ismael Himar Falcon-Suarez,&nbsp;Angus I. Best","doi":"10.1111/1365-2478.13607","DOIUrl":"10.1111/1365-2478.13607","url":null,"abstract":"<p>We present novel experimental measurements of acoustic velocity and attenuation in unconsolidated sand with water saturation within the sonic (well-log analogue) frequency range of 1–20 kHz. The measurements were conducted on jacketed sand packs with 0.5-m length and 0.069-m diameter using a bespoke acoustic pulse tube (a water-filled, stainless steel, thick-walled tube) under 10 MPa of hydrostatic confining pressure and 0.1 MPa of atmospheric pore pressure. We assess the fluid distribution effect on our measurements through an effective medium rock physics model, using uniform and patchy saturation approaches. Our velocity and attenuation (<i>Q</i>⁻¹) are accurate to ±2.4% and ±5.8%, respectively, based on comparisons with a theoretical transmission coefficient model. Velocity decreases with increasing water saturation up to ∼75% and then increases up to the maximum saturation. The velocity profiles across all four samples show similar values with small differences observed around 70%–90% water saturation, then converging again at maximum saturation. In contrast, the attenuation increases at low saturation, followed by a slight decrease towards maximum saturation. Velocity increases with frequency across all samples, which contrasts with the complex frequency-dependent pattern of attenuation. These results provide valuable insights into understanding elastic wave measurements over a broad frequency spectrum, particularly in the sonic range.</p>","PeriodicalId":12793,"journal":{"name":"Geophysical Prospecting","volume":"72 9","pages":"3316-3337"},"PeriodicalIF":1.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/1365-2478.13607","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}