Haibo Deng, Xiaoyan Cheng, Yongjian Zeng, Du Tianwei
Abstract When seismic waves propagate underground, subsurface media can absorb high-frequency components of the seismic waves, resulting in attenuation of the high-frequency portion of the seismic data. Therefore, the seismic resolution is low and it is difficult to provide the information needed for thin layer prediction. In this paper, a spectral fitting method with horizon constraints is proposed. This method fully takes into account the spectral characteristics and tectonic changes of the seismic data. It can effectively extend the seismic frequency bandwidth by spectral fitting and improve the seismic resolution. At the same time, the structural information is integrated into the high-resolution processing as the layer information is used to constrain the target equation, and more accurate spectral features of multi-channel data can be obtained. Then the spectral weighting coefficient can be calculated more accurately, resulting in more realistic and accurate seismic data. At the same time, the seismic phase is not destroyed by the processing, so the structural features become clearer, especially for small fractures and thin layers. This method is used for comparison with traditional robust deconvolution and statistical wavelet deconvolution. The spectral components are more faithful and the resolution is higher when processed with this method.
{"title":"A high-resolution method of spectral fitting with horizon constraints and its application","authors":"Haibo Deng, Xiaoyan Cheng, Yongjian Zeng, Du Tianwei","doi":"10.1093/jge/gxad042","DOIUrl":"https://doi.org/10.1093/jge/gxad042","url":null,"abstract":"Abstract When seismic waves propagate underground, subsurface media can absorb high-frequency components of the seismic waves, resulting in attenuation of the high-frequency portion of the seismic data. Therefore, the seismic resolution is low and it is difficult to provide the information needed for thin layer prediction. In this paper, a spectral fitting method with horizon constraints is proposed. This method fully takes into account the spectral characteristics and tectonic changes of the seismic data. It can effectively extend the seismic frequency bandwidth by spectral fitting and improve the seismic resolution. At the same time, the structural information is integrated into the high-resolution processing as the layer information is used to constrain the target equation, and more accurate spectral features of multi-channel data can be obtained. Then the spectral weighting coefficient can be calculated more accurately, resulting in more realistic and accurate seismic data. At the same time, the seismic phase is not destroyed by the processing, so the structural features become clearer, especially for small fractures and thin layers. This method is used for comparison with traditional robust deconvolution and statistical wavelet deconvolution. The spectral components are more faithful and the resolution is higher when processed with this method.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136162887","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}
Chao Chen, Xingyao Yin, Zuqing Chen, Xiaojing Liu, Jingbo Wang
Shale is a typical medium of transverse isotropy with a vertical axis of symmetry (VTI), and its strong anisotropy is mainly due to the combined effect of intrinsic anisotropy and that induced by horizontal fractures. To calculate the anisotropy parameters of shale, a physical rock model is built based on Hudson's thin-coin fracture model and Schoenberg's linear-sliding model, and an approximate theoretical calculation method for Thomsen's anisotropy parameters of VTI media with horizontal fractures is proposed. These calculation results using the proposed method confirm that this anisotropy contributed by horizontal fractures cannot be ignored to the overall anisotropy of shale. To simplify Rüger's formula that is an approximate theoretical formula for calculating the anisotropic reflection coefficients of VTI media, a new four-term approximate formula is derived in a standard reflectivity form based on Rüger's and Aki-Richards’ formulas. The simulation results of a VTI theoretical model and logging data of shale reservoirs show that there is only a small difference between the newly derived four-term formula and Rüger's formula for incidence angles less than 40°, and the new four-term formula can correctly reveal the seismic amplitude-versus-offset (AVO) characteristics of VTI media and fully retain the corresponding anisotropic seismic responses. Compared to Rüger's formula, the proposed new formula only has four terms of unknown parameters and can directly decouple Thomsen's anisotropy parameter ε from them, which helps to alleviate the ill-posed problems of simultaneous inversion of multiple parameters and enhance its application potential in seismic inversion of VTI media as shale.
{"title":"An approximate method for calculating anisotropy parameters and reflectivity of shales with horizontal fractures","authors":"Chao Chen, Xingyao Yin, Zuqing Chen, Xiaojing Liu, Jingbo Wang","doi":"10.1093/jge/gxad057","DOIUrl":"https://doi.org/10.1093/jge/gxad057","url":null,"abstract":"\u0000 Shale is a typical medium of transverse isotropy with a vertical axis of symmetry (VTI), and its strong anisotropy is mainly due to the combined effect of intrinsic anisotropy and that induced by horizontal fractures. To calculate the anisotropy parameters of shale, a physical rock model is built based on Hudson's thin-coin fracture model and Schoenberg's linear-sliding model, and an approximate theoretical calculation method for Thomsen's anisotropy parameters of VTI media with horizontal fractures is proposed. These calculation results using the proposed method confirm that this anisotropy contributed by horizontal fractures cannot be ignored to the overall anisotropy of shale. To simplify Rüger's formula that is an approximate theoretical formula for calculating the anisotropic reflection coefficients of VTI media, a new four-term approximate formula is derived in a standard reflectivity form based on Rüger's and Aki-Richards’ formulas. The simulation results of a VTI theoretical model and logging data of shale reservoirs show that there is only a small difference between the newly derived four-term formula and Rüger's formula for incidence angles less than 40°, and the new four-term formula can correctly reveal the seismic amplitude-versus-offset (AVO) characteristics of VTI media and fully retain the corresponding anisotropic seismic responses. Compared to Rüger's formula, the proposed new formula only has four terms of unknown parameters and can directly decouple Thomsen's anisotropy parameter ε from them, which helps to alleviate the ill-posed problems of simultaneous inversion of multiple parameters and enhance its application potential in seismic inversion of VTI media as shale.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46547474","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}
Husham A Ali Elbaloula, Gonçalo Soares de Oliveira, Denis J Schiozer
Abstract Water alternating gas (WAG) is a cyclical process that involves alternating water and gas injections with the primary goal to improve sweep efficiency by maintaining initial high pressure, slowing water and gas breakthrough, and lowering oil viscosity. The objective of this work is to apply and optimize a WAG strategy on a carbonate field with light oil, compare it to the initially planned water-flooding strategy, and investigate the capability of WAG to improve field production. In this research, a compositional reservoir simulator was used to model a WAG process by injecting produced gas into the reservoir, using the same well structure as an optimized water-flooding strategy. Subsequently, a WAG strategy was created, optimizing the number and locations of wells, to facilitate a comparative analysis of the two recovery methods. The WAG optimization involved a detailed assessment of variables such as bottom hole pressure (BHP), WAG cycle duration, maximum gas oil ratio (GOR), and well positioning, to achieve a high net present value (NPV). The study focuses on the application of WAG optimization modeling in unconventional reservoirs, specifically pre-salt carbonate reservoirs, and investigates its implications on production strategy and forecast, emphasizing its potential for maximizing NPV and oil recovery in a recently producing field. The results showed that WAG improved reservoir performance when compared to water injection and produced a greater amount of oil. This solution showed potential to be tested under uncertainties (reservoir heterogeneity, faults, fractures, karsts, vugs, etc.) as future steps.
{"title":"Water alternative gas (WAG) optimization for a heterogeneous Brazilian pre-salt carbonate reservoir","authors":"Husham A Ali Elbaloula, Gonçalo Soares de Oliveira, Denis J Schiozer","doi":"10.1093/jge/gxad053","DOIUrl":"https://doi.org/10.1093/jge/gxad053","url":null,"abstract":"Abstract Water alternating gas (WAG) is a cyclical process that involves alternating water and gas injections with the primary goal to improve sweep efficiency by maintaining initial high pressure, slowing water and gas breakthrough, and lowering oil viscosity. The objective of this work is to apply and optimize a WAG strategy on a carbonate field with light oil, compare it to the initially planned water-flooding strategy, and investigate the capability of WAG to improve field production. In this research, a compositional reservoir simulator was used to model a WAG process by injecting produced gas into the reservoir, using the same well structure as an optimized water-flooding strategy. Subsequently, a WAG strategy was created, optimizing the number and locations of wells, to facilitate a comparative analysis of the two recovery methods. The WAG optimization involved a detailed assessment of variables such as bottom hole pressure (BHP), WAG cycle duration, maximum gas oil ratio (GOR), and well positioning, to achieve a high net present value (NPV). The study focuses on the application of WAG optimization modeling in unconventional reservoirs, specifically pre-salt carbonate reservoirs, and investigates its implications on production strategy and forecast, emphasizing its potential for maximizing NPV and oil recovery in a recently producing field. The results showed that WAG improved reservoir performance when compared to water injection and produced a greater amount of oil. This solution showed potential to be tested under uncertainties (reservoir heterogeneity, faults, fractures, karsts, vugs, etc.) as future steps.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134919508","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}
Zilong Ye, Jianping Huang, Yi Shen, X. Mu, Q. Zhan
Seismic anisotropy exists in various type of strata and should be considered in seismic imaging schemes. Seismic imaging algorithms based on isotropic assumption neglect the impacts of anisotropy on seismic data, which causes migration artifact and waveform distortion. To correct the effects of anisotropy on seismic wave propagation, we propose an imaging algorithm that performs least-squares reverse time migration in vertical transversely isotropic acoustic media. We derive the following operators to implement this algorithm, the de-migration operator, its adjoint migration operator and the corresponding gradient. However, an inaccurate estimated source wavelet will introduce the error in the seismic simulation, and thus increase the mismatch between observed and synthetic data for least-squares reverse time migration. In addition, the noises, especially the noises with abnormal amplitudes in the seismic data, damage the inversion convergence and reduce the imaging resolution. To improve the image quality, we propose to use convolved wavefields between observed and synthetic data so that such mismatch can be independent of the source wavelets. Also, we employ the student's t-distribution instead of L2 norm in our inversion scheme to better handle the seismic noise. Its implementation only modifies the gradient of the conventional least square reverse time migration scheme. Our numerical tests show a clear improvement using our proposed imaging algorithm when compared with the conventional isotropic migration scheme for the anisotropic data. Also, the synthetic examples demonstrate the feasibility and effectiveness of our proposed source-independent algorithm using the student's t-distribution.
{"title":"Source-independent least-squares Reverse time migration in vertical transversely isotropic Media based on the student's t-distribution","authors":"Zilong Ye, Jianping Huang, Yi Shen, X. Mu, Q. Zhan","doi":"10.1093/jge/gxad054","DOIUrl":"https://doi.org/10.1093/jge/gxad054","url":null,"abstract":"\u0000 Seismic anisotropy exists in various type of strata and should be considered in seismic imaging schemes. Seismic imaging algorithms based on isotropic assumption neglect the impacts of anisotropy on seismic data, which causes migration artifact and waveform distortion. To correct the effects of anisotropy on seismic wave propagation, we propose an imaging algorithm that performs least-squares reverse time migration in vertical transversely isotropic acoustic media. We derive the following operators to implement this algorithm, the de-migration operator, its adjoint migration operator and the corresponding gradient. However, an inaccurate estimated source wavelet will introduce the error in the seismic simulation, and thus increase the mismatch between observed and synthetic data for least-squares reverse time migration. In addition, the noises, especially the noises with abnormal amplitudes in the seismic data, damage the inversion convergence and reduce the imaging resolution. To improve the image quality, we propose to use convolved wavefields between observed and synthetic data so that such mismatch can be independent of the source wavelets. Also, we employ the student's t-distribution instead of L2 norm in our inversion scheme to better handle the seismic noise. Its implementation only modifies the gradient of the conventional least square reverse time migration scheme. Our numerical tests show a clear improvement using our proposed imaging algorithm when compared with the conventional isotropic migration scheme for the anisotropic data. Also, the synthetic examples demonstrate the feasibility and effectiveness of our proposed source-independent algorithm using the student's t-distribution.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44733710","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}
The presence of an urban active fault carries a geological hazard risk that threatens urban construction. Therefore, detecting such faults is crucial for mitigating potential risks and ensuring safe urban development. The grounded-wire source short-offset transient electromagnetic method (SOTEM) offers an opportunity to identify faults with high-conductivity. The results of a SOTEM survey conducted in Shunping, Hebei Province, were presented to detect buried faults and locate the industrial park. Data were analysed using the one-dimensional inversion method with SOTEMsoft software, which was denoised using the short-time sliding window adaptive singular value decomposition algorithm based on the wavelet threshold. Despite the challenges posed by urban features, particularly traffic, the survey results located the fault and hold significant potential to reveal its extent and depth. The study highlights the importance of avoiding fault sites during urban construction, even though the area is currently tectonically stable. This paper reveals an unusual opportunity to study the effectiveness of electromagnetic methods for detecting buried faults in cities and reveal geological structures covered by Quaternary formations.
{"title":"Investigation of urban active faults using the short-offset transient electromagnetic method: An example from Shunping, Hebei Province, China","authors":"Wanting Song, Weiying Chen, Yiming He, Kangxin Lei, Pengfei Lv, Yang Zhao","doi":"10.1093/jge/gxad055","DOIUrl":"https://doi.org/10.1093/jge/gxad055","url":null,"abstract":"\u0000 The presence of an urban active fault carries a geological hazard risk that threatens urban construction. Therefore, detecting such faults is crucial for mitigating potential risks and ensuring safe urban development. The grounded-wire source short-offset transient electromagnetic method (SOTEM) offers an opportunity to identify faults with high-conductivity. The results of a SOTEM survey conducted in Shunping, Hebei Province, were presented to detect buried faults and locate the industrial park. Data were analysed using the one-dimensional inversion method with SOTEMsoft software, which was denoised using the short-time sliding window adaptive singular value decomposition algorithm based on the wavelet threshold. Despite the challenges posed by urban features, particularly traffic, the survey results located the fault and hold significant potential to reveal its extent and depth. The study highlights the importance of avoiding fault sites during urban construction, even though the area is currently tectonically stable. This paper reveals an unusual opportunity to study the effectiveness of electromagnetic methods for detecting buried faults in cities and reveal geological structures covered by Quaternary formations.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47101588","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}
In the field of complex underground geological structures and irregular topography, prestack seismic data often have a low Signal-to-Noise Ratio (SNR), where weakly reflected signals are buried beneath strong incoherent, and scattered noise. Stacking, such as beamforming along the moveout surfaces of coherent local events, can significantly improve seismic data quality. Accurate and efficient estimation of the moveout for an irregular acquisition geometry and uneven illumination is important in a complex environment. In this paper, a new optimal stacking approach for enhancing weak prestack reflection signals is presented. The proposed method mainly includes regional division and moveout estimation. Optimal stacking should be implemented within local time and space domains. Based on beam ray theory, we designed a reasonable regional division of the Common-Shot (CS), Common-Receiver (CR), and Common-Middle-Point (CMP) domains. Then, we proposed using the sparse radon transform and dynamic waveform matching method to estimate the moveout surfaces of local reflection events. The sparse radon transform was applied to obtain the linear moveout to ensure the correctness of the reflection wave direction. The residual nonlinear disturbance was estimated using the dynamic waveform matching method. Tests on synthetic and field data demonstrated the effectiveness of the proposed method, which can effectively improve the SNR of prestack seismic data and attenuate incoherent noise.
{"title":"Enhancing prestack seismic data by sparse radon transform and dynamic waveform matching","authors":"Fangzheng Ma, Chengliang Wu, Sheng Shen","doi":"10.1093/jge/gxad050","DOIUrl":"https://doi.org/10.1093/jge/gxad050","url":null,"abstract":"\u0000 In the field of complex underground geological structures and irregular topography, prestack seismic data often have a low Signal-to-Noise Ratio (SNR), where weakly reflected signals are buried beneath strong incoherent, and scattered noise. Stacking, such as beamforming along the moveout surfaces of coherent local events, can significantly improve seismic data quality. Accurate and efficient estimation of the moveout for an irregular acquisition geometry and uneven illumination is important in a complex environment. In this paper, a new optimal stacking approach for enhancing weak prestack reflection signals is presented. The proposed method mainly includes regional division and moveout estimation. Optimal stacking should be implemented within local time and space domains. Based on beam ray theory, we designed a reasonable regional division of the Common-Shot (CS), Common-Receiver (CR), and Common-Middle-Point (CMP) domains. Then, we proposed using the sparse radon transform and dynamic waveform matching method to estimate the moveout surfaces of local reflection events. The sparse radon transform was applied to obtain the linear moveout to ensure the correctness of the reflection wave direction. The residual nonlinear disturbance was estimated using the dynamic waveform matching method. Tests on synthetic and field data demonstrated the effectiveness of the proposed method, which can effectively improve the SNR of prestack seismic data and attenuate incoherent noise.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42068428","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}
Hashem Omrani, M. Hajipour, S. Jamshidi, M. Behnood
This study aims to improve rock-type classification by analyzing core data based on the water–oil primary drainage capillary pressure method. A modified empirical equation is proposed using permeability, porosity, and irreducible water saturation to classify rock types based on water–oil primary drainage capillary pressure. We used primary drainage capillary pressure data measured in carbonate and sandstone samples in the Ahvaz Asmari and Mansouri oilfields to evaluate the characterization number (Cn) method. This study consists of two main parts. First, the Cn method is introduced to rock typing, and the permeability is calculated from well log data. In the second part, we present rock-type classification when the water saturation of the formation is more than the irreducible water saturation. The novelty of this work is a simple and efficient technique to rock-type classification using the Cn method. In addition, we present a procedure to assign rock types for the transition zone using the Cn method. Moreover, this study systematically investigates the role of irreducible water saturation in rock typing. The innovation of this work lies in its ability to classify rocks in heterogeneous reservoirs for carbonate and sandstone lithology and allow for the calculation of permeability more accurately from well log data. The comparison results between the Cn method and the flow zone indicator method show the robust clustering ability of the Cn method.
{"title":"A new method in reservoir rock classification in carbonate and sandstone formations","authors":"Hashem Omrani, M. Hajipour, S. Jamshidi, M. Behnood","doi":"10.1093/jge/gxad056","DOIUrl":"https://doi.org/10.1093/jge/gxad056","url":null,"abstract":"\u0000 This study aims to improve rock-type classification by analyzing core data based on the water–oil primary drainage capillary pressure method. A modified empirical equation is proposed using permeability, porosity, and irreducible water saturation to classify rock types based on water–oil primary drainage capillary pressure. We used primary drainage capillary pressure data measured in carbonate and sandstone samples in the Ahvaz Asmari and Mansouri oilfields to evaluate the characterization number (Cn) method. This study consists of two main parts. First, the Cn method is introduced to rock typing, and the permeability is calculated from well log data. In the second part, we present rock-type classification when the water saturation of the formation is more than the irreducible water saturation. The novelty of this work is a simple and efficient technique to rock-type classification using the Cn method. In addition, we present a procedure to assign rock types for the transition zone using the Cn method. Moreover, this study systematically investigates the role of irreducible water saturation in rock typing. The innovation of this work lies in its ability to classify rocks in heterogeneous reservoirs for carbonate and sandstone lithology and allow for the calculation of permeability more accurately from well log data. The comparison results between the Cn method and the flow zone indicator method show the robust clustering ability of the Cn method.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49061727","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}
De-fu Zhu, Xingwang Ji, Y. Huo, Zhonglun Wang, Biaobiao Yu, Deyu Wang
The stable loading and operation of a coal bunker is critical for efficient production. In this study, the coal particle contact parameters were calibrated based on the angle of repose characteristics. The loading and discharging process of the coal bunker was simulated using the EDEM program. In addition, the flow pattern of the coal particles and the distribution characteristics of the wall pressure were investigated. The results indicate that the coal particles in the bunker can be divided into two flow patterns: mass flow and funnel flow. During discharging, the wall pressure fluctuated and exhibited a local over-pressure phenomenon, with a maximum pressure coefficient of 1.75. Finally, this study provides a reasonable explanation for the transformation of the flow pattern of coal particles and the distribution characteristics of wall pressure based on the mechanism of pressure arch influence. The findings of this study can provide theoretical guidance for designing coal bunker structures.
{"title":"Numerical Investigation of Particles Flow Pattern and Pressure Distribution of Coal Bunker","authors":"De-fu Zhu, Xingwang Ji, Y. Huo, Zhonglun Wang, Biaobiao Yu, Deyu Wang","doi":"10.1093/jge/gxad052","DOIUrl":"https://doi.org/10.1093/jge/gxad052","url":null,"abstract":"\u0000 The stable loading and operation of a coal bunker is critical for efficient production. In this study, the coal particle contact parameters were calibrated based on the angle of repose characteristics. The loading and discharging process of the coal bunker was simulated using the EDEM program. In addition, the flow pattern of the coal particles and the distribution characteristics of the wall pressure were investigated. The results indicate that the coal particles in the bunker can be divided into two flow patterns: mass flow and funnel flow. During discharging, the wall pressure fluctuated and exhibited a local over-pressure phenomenon, with a maximum pressure coefficient of 1.75. Finally, this study provides a reasonable explanation for the transformation of the flow pattern of coal particles and the distribution characteristics of wall pressure based on the mechanism of pressure arch influence. The findings of this study can provide theoretical guidance for designing coal bunker structures.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47992416","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}
3D holographic azimuthal electromagnetic resistivity logging while drilling is a convenient and efficient technology to obtain information about formation. It has the advantages of instant, accurate. It can be applied to the field of engineering such as evaluating the anisotropy and detecting nearby geological interfaces. A 3D electromagnetic resistivity azimuthal LWD instrument consists of coaxial, coplanar, tilted, and orthogonal antenna systems, being able to solve for all nine components. The explicit generic formulation is derived from presenting the response for a basic unit of one arbitrarily-oriented transmitter and one arbitrarily-oriented receiver. Combining the responses of basic units with different transmitter-receiver spacing and different components, an ‘anisotropy signal’ is defined with the phase difference${M_{px}}$ and amplitude ratio ${M_{ax}}$. A ‘boundary signal’ is also defined with the phase difference ${M_{pz}}$ and amplitude ratio ${M_{az}}$. Forward simulation results show that the 2MHz ${M_{px}}$ can accurately identify geological anisotropy in highly deviated and horizontal wells. The ${M_{az}}$can detect geological interfaces in highly deviated and horizontal wells. the 100KHz${rm{,,}}{M_{az}},,$can detect geological boundaries in the range of 8m-9m.
{"title":"Anisotropy evaluation and interface detection based on 3D holographic azimuthal electromagnetic resistivity logging instrument","authors":"Liqi Fang, Yuxin Bai, Shuyu Guo, Xiao Liu, Siyu Tang, Xiaoqiu Li, Jiaqi Xiao","doi":"10.1093/jge/gxad046","DOIUrl":"https://doi.org/10.1093/jge/gxad046","url":null,"abstract":"\u0000 3D holographic azimuthal electromagnetic resistivity logging while drilling is a convenient and efficient technology to obtain information about formation. It has the advantages of instant, accurate. It can be applied to the field of engineering such as evaluating the anisotropy and detecting nearby geological interfaces. A 3D electromagnetic resistivity azimuthal LWD instrument consists of coaxial, coplanar, tilted, and orthogonal antenna systems, being able to solve for all nine components. The explicit generic formulation is derived from presenting the response for a basic unit of one arbitrarily-oriented transmitter and one arbitrarily-oriented receiver. Combining the responses of basic units with different transmitter-receiver spacing and different components, an ‘anisotropy signal’ is defined with the phase difference${M_{px}}$ and amplitude ratio ${M_{ax}}$. A ‘boundary signal’ is also defined with the phase difference ${M_{pz}}$ and amplitude ratio ${M_{az}}$. Forward simulation results show that the 2MHz ${M_{px}}$ can accurately identify geological anisotropy in highly deviated and horizontal wells. The ${M_{az}}$can detect geological interfaces in highly deviated and horizontal wells. the 100KHz${rm{,,}}{M_{az}},,$can detect geological boundaries in the range of 8m-9m.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42875126","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}
First-arrival slope tomography (FAST) introduces first-arrival slopes, corresponding to the horizontal components of the slowness vectors, at the receiver and source positions to supplement first-arrival traveltime for better guiding ray propagation in the media until the best match is achieved with the observed data. FAST can recover the velocity model with higher resolution and precision than first-arrival traveltime tomography (FATT) but is computationally intensive. In this context, we propose a high-precision and high-efficiency approach, referred to as HFAST. HFAST redefines one of the slopes using the reciprocity principle and simultaneously employs the first-arrival traveltime and slopes to ensure high-quality model building. On the other hand, HFAST extracts calculated data and derives the gradient of the misfit function from the solutions of relatively limited forward and inverse problems, resulting in a low computational cost. The cost of HFAST is proportional to the minimum between the receivers and sources, whereas the cost of FAST is scaled to the sum of the receivers and sources. Numerical experiments involving the checkerboard and SEAM II Foothill models demonstrate that HFAST can achieve a higher inversion precision than FATT, especially in the recovery of small-scale anomalies and the presence of velocity reversal. Moreover, HFAST is more computationally efficient than FAST and suitable for managing large data sets. Therefore, HFAST can be regarded as a valuable supplement to current first-arrival-based model building methods and has the potential to be applied in static corrections, prestack depth migration, and waveform inversion in the future.
首次到达斜率层析成像（FAST）在接收器和源位置引入与慢度矢量的水平分量相对应的首次到达斜率，以补充首次到达行程时间，从而更好地引导射线在介质中传播，直到与观测数据实现最佳匹配。FAST可以以比首次到达旅行时间断层扫描（FATT）更高的分辨率和精度恢复速度模型，但计算量大。在这种情况下，我们提出了一种高精度和高效的方法，称为HFAST。HFAST使用互易原理重新定义了其中一个斜坡，并同时采用了首次到达行程时间和斜坡，以确保高质量的模型构建。另一方面，HFAST提取计算数据，并从相对有限的正向和反向问题的解中导出失配函数的梯度，从而降低了计算成本。HFAST的成本与接收器和源之间的最小值成比例，而FAST的成本则按比例缩放为接收器和源的总和。涉及棋盘和SEAM II Foothill模型的数值实验表明，HFAST可以实现比FATT更高的反演精度，特别是在小规模异常恢复和速度反转的情况下。此外，HFAST在计算上比FAST更高效，适合管理大型数据集。因此，HFAST可以被视为对当前基于初到的建模方法的一种有价值的补充，并有可能在未来的静态校正、叠前深度偏移和波形反演中应用。
{"title":"High-precision and high-efficiency first-arrival slope tomography via eikonal solvers and the adjoint-state method","authors":"Yong Li, Gulan Zhang, Guanghui Hu, Ke Li, Yiliang Luo, Chenxi Liang, Jing Duan","doi":"10.1093/jge/gxad051","DOIUrl":"https://doi.org/10.1093/jge/gxad051","url":null,"abstract":"\u0000 First-arrival slope tomography (FAST) introduces first-arrival slopes, corresponding to the horizontal components of the slowness vectors, at the receiver and source positions to supplement first-arrival traveltime for better guiding ray propagation in the media until the best match is achieved with the observed data. FAST can recover the velocity model with higher resolution and precision than first-arrival traveltime tomography (FATT) but is computationally intensive. In this context, we propose a high-precision and high-efficiency approach, referred to as HFAST. HFAST redefines one of the slopes using the reciprocity principle and simultaneously employs the first-arrival traveltime and slopes to ensure high-quality model building. On the other hand, HFAST extracts calculated data and derives the gradient of the misfit function from the solutions of relatively limited forward and inverse problems, resulting in a low computational cost. The cost of HFAST is proportional to the minimum between the receivers and sources, whereas the cost of FAST is scaled to the sum of the receivers and sources. Numerical experiments involving the checkerboard and SEAM II Foothill models demonstrate that HFAST can achieve a higher inversion precision than FATT, especially in the recovery of small-scale anomalies and the presence of velocity reversal. Moreover, HFAST is more computationally efficient than FAST and suitable for managing large data sets. Therefore, HFAST can be regarded as a valuable supplement to current first-arrival-based model building methods and has the potential to be applied in static corrections, prestack depth migration, and waveform inversion in the future.","PeriodicalId":54820,"journal":{"name":"Journal of Geophysics and Engineering","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49059550","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}
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