Subjects -> EARTH SCIENCES (Total: 771 journals)
    - EARTH SCIENCES (527 journals)
    - GEOLOGY (94 journals)
    - GEOPHYSICS (33 journals)
    - HYDROLOGY (29 journals)
    - OCEANOGRAPHY (88 journals)

EARTH SCIENCES (527 journals)            First | 1 2 3     

Showing 201 - 371 of 371 Journals sorted alphabetically
Hydrological Processes     Hybrid Journal   (Followers: 44)
Hydrology and Earth System Sciences     Open Access   (Followers: 38)
ICES Journal of Marine Science: Journal du Conseil     Hybrid Journal   (Followers: 53)
IEEE Geoscience and Remote Sensing Letters     Hybrid Journal   (Followers: 151)
IEEE Geoscience and Remote Sensing Magazine     Hybrid Journal   (Followers: 6)
IEEE Journal of Oceanic Engineering     Hybrid Journal   (Followers: 11)
Indian Geotechnical Journal     Hybrid Journal   (Followers: 4)
Indonesian Journal on Geoscience     Open Access   (Followers: 1)
Inland Waters     Hybrid Journal  
Innovative Infrastructure Solutions     Hybrid Journal  
Interdisciplinary Environmental Review     Hybrid Journal   (Followers: 3)
International Geology Review     Hybrid Journal   (Followers: 17)
International Journal of Advanced Geosciences     Open Access   (Followers: 2)
International Journal of Advanced Remote Sensing and GIS     Open Access   (Followers: 50)
International Journal of Applied Earth Observation and Geoinformation     Open Access   (Followers: 36)
International Journal of Coal Geology     Hybrid Journal   (Followers: 2)
International Journal of Disaster Risk Reduction     Hybrid Journal   (Followers: 18)
International Journal of Earth Sciences     Hybrid Journal   (Followers: 37)
International Journal of Earthquake and Impact Engineering     Hybrid Journal   (Followers: 4)
International Journal of Energetic Materials     Full-text available via subscription  
International Journal of Environment and Geoinformatics     Open Access   (Followers: 4)
International Journal of Geo-Engineering     Open Access   (Followers: 2)
International Journal of Geographical Information Science     Hybrid Journal   (Followers: 55)
International Journal of Geomechanics     Full-text available via subscription   (Followers: 6)
International Journal of Geosciences     Open Access   (Followers: 10)
International Journal of Geosynthetics and Ground Engineering     Full-text available via subscription   (Followers: 3)
International Journal of Geotechnical Earthquake Engineering     Full-text available via subscription   (Followers: 9)
International Journal of Image and Data Fusion     Hybrid Journal   (Followers: 3)
International Journal of Remote Sensing     Hybrid Journal   (Followers: 144)
International Journal of Remote Sensing Applications     Open Access   (Followers: 49)
International Journal of Soil, Sediment and Water     Open Access   (Followers: 4)
International Journal of Speleology     Open Access   (Followers: 3)
Iraqi National Journal of Earth Sciences     Open Access  
iScience     Open Access   (Followers: 1)
Island Arc     Hybrid Journal   (Followers: 5)
ISPRS International Journal of Geo-Information     Open Access   (Followers: 5)
Italian Journal of Geosciences     Open Access  
Izvestiya, Atmospheric and Oceanic Physics     Full-text available via subscription   (Followers: 1)
Izvestiya, Physics of the Solid Earth     Hybrid Journal   (Followers: 2)
Jahresberichte und Mitteilungen des Oberrheinischen Geologischen Vereins     Full-text available via subscription   (Followers: 2)
JETP Letters     Hybrid Journal   (Followers: 3)
Journal of Earth Science & Climatic Change     Open Access   (Followers: 14)
Journal of Advances in Modeling Earth Systems     Open Access   (Followers: 5)
Journal of African Earth Sciences     Hybrid Journal   (Followers: 11)
Journal of Analytical and Numerical Methods in Mining Engineering     Open Access  
Journal of Applied Geophysics     Hybrid Journal   (Followers: 15)
Journal of Applied Volcanology     Open Access   (Followers: 7)
Journal of Arid Land     Hybrid Journal  
Journal of Asian Earth Sciences     Hybrid Journal   (Followers: 15)
Journal of Asian Earth Sciences : X     Open Access  
Journal of Atmospheric and Oceanic Technology     Hybrid Journal   (Followers: 33)
Journal of Atmospheric and Solar-Terrestrial Physics     Hybrid Journal   (Followers: 133)
Journal of Big History     Open Access   (Followers: 3)
Journal of Coastal Conservation     Hybrid Journal   (Followers: 6)
Journal of Coastal Research     Hybrid Journal   (Followers: 31)
Journal of Contemporary Physics (Armenian Academy of Sciences)     Hybrid Journal   (Followers: 9)
Journal of Contemporary Water Resource & Education     Hybrid Journal   (Followers: 2)
Journal of Earth Science     Hybrid Journal   (Followers: 12)
Journal of Earth System Science     Open Access   (Followers: 52)
Journal of Earth, Environment and Health Sciences     Open Access   (Followers: 2)
Journal of Earthquake and Tsunami     Hybrid Journal   (Followers: 2)
Journal of Earthquake Engineering     Hybrid Journal   (Followers: 14)
Journal of Environment and Earth Science     Open Access   (Followers: 11)
Journal of Environmental & Engineering Geophysics     Hybrid Journal   (Followers: 2)
Journal of Geodesy     Hybrid Journal   (Followers: 9)
Journal of Geodesy and Geoinformation     Open Access   (Followers: 2)
Journal of Geodynamics     Hybrid Journal   (Followers: 6)
Journal of Geography, Environment and Earth Science International     Open Access  
Journal of Geology     Full-text available via subscription   (Followers: 30)
Journal of Geomorphology     Open Access   (Followers: 3)
Journal of Geophysical Research : Atmospheres     Partially Free   (Followers: 134)
Journal of Geophysical Research : Biogeosciences     Full-text available via subscription   (Followers: 34)
Journal of Geophysical Research : Earth Surface     Partially Free   (Followers: 59)
Journal of Geophysical Research : Oceans     Partially Free   (Followers: 60)
Journal of Geophysical Research : Planets     Full-text available via subscription   (Followers: 116)
Journal of Geophysical Research : Solid Earth     Full-text available via subscription   (Followers: 57)
Journal of Geophysical Research : Space Physics     Full-text available via subscription   (Followers: 136)
Journal of Geophysics and Engineering     Hybrid Journal   (Followers: 2)
Journal of Geoscience Education     Hybrid Journal   (Followers: 1)
Journal of Geoscience, Engineering, Environment, and Technology     Open Access   (Followers: 1)
Journal of Geosciences     Open Access   (Followers: 5)
Journal of Geosciences and Geomatics     Open Access   (Followers: 1)
Journal of Geospatial Applications in Natural Resources     Open Access  
Journal of Geotechnical and Geoenvironmental Engineering     Full-text available via subscription   (Followers: 30)
Journal of Geotechnical Engineering     Full-text available via subscription   (Followers: 4)
Journal of Great Lakes Research     Hybrid Journal   (Followers: 5)
Journal of Hydro-environment Research     Full-text available via subscription   (Followers: 13)
Journal of Hydrologic Engineering     Full-text available via subscription   (Followers: 40)
Journal of International Maritime Safety, Environmental Affairs, and Shipping     Open Access   (Followers: 1)
Journal of Life and Earth Science     Open Access  
Journal of Marine Medical Society     Open Access   (Followers: 1)
Journal of Marine Research     Full-text available via subscription   (Followers: 20)
Journal of Marine Science and Technology     Hybrid Journal   (Followers: 3)
Journal of Marine Systems     Hybrid Journal   (Followers: 9)
Journal of Metamorphic Geology     Hybrid Journal   (Followers: 15)
Journal of Mining Science     Hybrid Journal   (Followers: 2)
Journal of Mountain Science     Hybrid Journal  
Journal of Natural Gas Geoscience     Open Access  
Journal of Ocean and Climate     Open Access   (Followers: 9)
Journal of Oceanology and Limnology     Hybrid Journal   (Followers: 3)
Journal of Petroleum Exploration and Production Technology     Open Access   (Followers: 2)
Journal of Petroleum Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Petrology     Hybrid Journal   (Followers: 11)
Journal of Plasma Physics     Hybrid Journal   (Followers: 21)
Journal of Population and Sustainability     Open Access  
Journal of Quaternary Science     Hybrid Journal   (Followers: 31)
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (Followers: 3)
Journal of Sea Research     Hybrid Journal   (Followers: 6)
Journal of Sedimentary Environments     Open Access  
Journal of Seismology     Hybrid Journal   (Followers: 9)
Journal of Spatial Information Science     Open Access   (Followers: 4)
Journal of Structural Geology     Hybrid Journal   (Followers: 26)
Journal of Systematic Palaeontology     Hybrid Journal   (Followers: 7)
Journal of the Atmospheric Sciences     Hybrid Journal   (Followers: 83)
Journal of the Geological Society     Hybrid Journal   (Followers: 17)
Journal of the Royal Society of New Zealand     Hybrid Journal   (Followers: 48)
Journal of the World Aquaculture Society     Hybrid Journal   (Followers: 13)
Journal of Volcanology and Geothermal Research     Hybrid Journal   (Followers: 17)
Journal of Water and Climate Change     Open Access   (Followers: 52)
Journal on Geoinformatics, Nepal     Open Access   (Followers: 2)
Jurnal Ilmiah Perikanan dan Kelautan / Scientific Journal of Fisheries and Marine     Open Access  
Kartografija i geoinformacije (Cartography and Geoinformation)     Open Access  
Lake and Reservoir Management     Hybrid Journal   (Followers: 7)
Landslides     Hybrid Journal   (Followers: 26)
Latin American Journal of Sedimentology and Basin Analysis     Open Access   (Followers: 1)
Lethaia     Hybrid Journal   (Followers: 5)
Letters in Mathematical Physics     Hybrid Journal   (Followers: 4)
Limnologica     Hybrid Journal   (Followers: 4)
Limnology     Hybrid Journal   (Followers: 9)
Lithology and Mineral Resources     Hybrid Journal   (Followers: 3)
Lithos     Hybrid Journal   (Followers: 9)
Malaysian Journal of Geosciences     Open Access  
Marine and Freshwater Research     Hybrid Journal   (Followers: 6)
Marine and Petroleum Geology     Hybrid Journal   (Followers: 21)
Marine Biology Research: New for 2005     Hybrid Journal   (Followers: 2)
Marine Economics and Management     Open Access   (Followers: 3)
Marine Environmental Research     Hybrid Journal   (Followers: 31)
Marine Geodesy     Hybrid Journal   (Followers: 4)
Marine Geology     Hybrid Journal   (Followers: 31)
Marine Geophysical Researches     Hybrid Journal   (Followers: 5)
Marine Georesources & Geotechnology     Hybrid Journal  
Marine Mammal Science     Hybrid Journal   (Followers: 10)
Marine Policy     Hybrid Journal   (Followers: 61)
Mathematical Geosciences     Hybrid Journal   (Followers: 4)
Mathematical Physics, Analysis and Geometry     Hybrid Journal   (Followers: 3)
Mediterranean Geoscience Reviews     Hybrid Journal  
Meteoritics & Planetary Science     Hybrid Journal   (Followers: 18)
Meteorologische Zeitschrift     Full-text available via subscription   (Followers: 4)
Mineralium Deposita     Hybrid Journal   (Followers: 4)
Mineralogia     Open Access   (Followers: 2)
Mineralogy and Petrology     Hybrid Journal   (Followers: 2)
Mineria y Geologia     Open Access  
Mining, Metallurgy & Exploration     Hybrid Journal  
Momona Ethiopian Journal of Science     Open Access   (Followers: 5)
Mongolian Geoscientist     Open Access  
Moscow University Geology Bulletin     Hybrid Journal  
Moscow University Physics Bulletin     Hybrid Journal  
Natural Hazards     Hybrid Journal   (Followers: 53)
Natural Hazards and Earth System Sciences (NHESS)     Open Access   (Followers: 10)
Natural Hazards and Earth System Sciences Discssions     Open Access  
Natural Hazards Research     Open Access  
Natural Hazards Review     Full-text available via subscription   (Followers: 16)
Natural Resources & Engineering     Hybrid Journal  
Natural Resources Research     Hybrid Journal   (Followers: 8)
Nature Geoscience     Full-text available via subscription   (Followers: 162)
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen     Full-text available via subscription   (Followers: 3)
Neues Jahrbuch für Mineralogie - Abhandlungen     Full-text available via subscription   (Followers: 1)
Newsletters on Stratigraphy     Full-text available via subscription   (Followers: 2)
Nonlinear Processes in Geophysics (NPG)     Open Access  
Nonlinear Processes in Geophysics Discussions     Open Access  
Ocean & Coastal Management     Hybrid Journal   (Followers: 62)
Ocean Development & International Law     Hybrid Journal   (Followers: 15)
Ocean Dynamics     Hybrid Journal   (Followers: 6)
Ocean Engineering     Hybrid Journal   (Followers: 6)
Ocean Modelling     Hybrid Journal   (Followers: 12)
Ocean Science (OS)     Open Access   (Followers: 7)
Ocean Science Journal     Hybrid Journal   (Followers: 6)
Open Geospatial Data, Software and Standards     Open Access   (Followers: 3)
Open Journal of Earthquake Research     Open Access   (Followers: 3)
Open Journal of Soil Science     Open Access   (Followers: 9)
Ore and Energy Resource Geology     Open Access  
Ore Geology Reviews     Hybrid Journal   (Followers: 11)
Organic Geochemistry     Hybrid Journal   (Followers: 4)
Osterreichische Wasser- und Abfallwirtschaft     Hybrid Journal  
Paläontologische Zeitschrift     Hybrid Journal   (Followers: 4)
Papers in Palaeontology     Hybrid Journal  
Permafrost and Periglacial Processes     Hybrid Journal   (Followers: 5)
Perspectives of Earth and Space Scientists i     Open Access   (Followers: 1)
Petroleum Geoscience     Hybrid Journal   (Followers: 5)
Petroleum Science     Open Access  
Petrology     Full-text available via subscription   (Followers: 6)
PFG : Journal of Photogrammetry, Remote Sensing and Geoinformation Science     Hybrid Journal   (Followers: 4)
Photogrammetrie - Fernerkundung - Geoinformation     Full-text available via subscription  
Physical Geography     Hybrid Journal   (Followers: 8)
Physical Science International Journal     Open Access  
Physics of Life Reviews     Hybrid Journal   (Followers: 1)
Physics of Metals and Metallography     Hybrid Journal   (Followers: 18)
Physics of Plasmas     Hybrid Journal   (Followers: 10)
Physics of the Earth and Planetary Interiors     Hybrid Journal   (Followers: 34)
Physics of the Solid State     Hybrid Journal   (Followers: 7)

  First | 1 2 3     

Similar Journals
Journal Cover
Journal of Geophysics and Engineering
Journal Prestige (SJR): 0.524
Citation Impact (citeScore): 1
Number of Followers: 2  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1742-2132 - ISSN (Online) 1742-2140
Published by Oxford University Press Homepage  [419 journals]
  • Inversion of horizontal in situ stress field based on wide-azimuth seismic
           data

    • Free pre-print version: Loading...

      Authors: Yang J; Zhang F, Li C.
      Pages: 131 - 141
      Abstract: AbstractIn situ stress is a significant rock mechanics parameter, which is widely used in many aspects of the petroleum industry. Horizontal in situ stress is an important part of in situ stress. Hence, how to obtain accurate information as to horizontal stress can vary with azimuth has been widely explored. A new prediction method for in situ stress on a horizontal plane is proposed here. This new method analyses the relationship between seismic data, fracture orientation and a horizontal in situ stress field. Through a series of actual data, it is found that azimuth seismic data and azimuth elastic modulus can effectively point out the direction of the horizontal stress. Meanwhile, the magnitude of horizontal stress is shown to be closely related to a combination of rock elastic modulus and seismic amplitude according to a further analysis of log and wide-azimuth seismic data. Under this premise, an objective function of horizontal in situ stress field inversion using azimuth seismic data is established. Finally, the inversion of a horizontal in situ stress field based on wide-azimuth seismic data is realized. This inversion method can simultaneously invert the maximum horizontal stress, minimum horizontal stress and their orientations, which optimizes the prediction process of a horizontal in situ stress field and establish a new method for the prediction of horizontal in situ stress fields. The application of actual data also verifies the prediction accuracy of this method.
      PubDate: Mon, 21 Mar 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac006
      Issue No: Vol. 19, No. 2 (2022)
       
  • Structural implications of potential field data on Southeastern North
           America

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      Authors: Alarifi S.
      Pages: 142 - 156
      Abstract: AbstractThe fault system of Eastern Piedmont could be extensive in the East of the USA. Debates remain regarding the sutures zone, contacts and faults between terranes, especially underneath the coastal sediment. However, in this study, a new interpretation of the structures and contacts of the southeastern margin was based on regional land gravity anomaly and magnetic anomaly maps. To delineate and investigate the subsurface geological structures in the southern Appalachian belt and underneath the coastal sediment that covers the southeastern half of the study area, the gravity and magnetic maps were subjected to several filter techniques. The anomalies maps were enhanced by applying the reduction to pole (RTP), analytical signal (AS), tilt derivative (TDR), horizontal gradient (HG), direction filter and power spectrum techniques. The power spectrum filter was applied to separate the regional-residual anomaly. The results of regional anomaly maps display elongate high amplitude anomalies lie in the south that are related to deep-seated igneous mafic intrusive and basaltic lavas emplacement. The directional filter was used to eliminate the sutural trend of the Jurassic dikes that intruded the study area. The result displays the structural contacts clearly after removing the anomalies of the Jurassic. Finally, the edge detection filters (TDR, HG, AS) from the gravity and magnetic maps helped in mapping the anomaly contact of the subsurface bodies. The apparent structural signature of the interpreted contacts confirmed the presence of these structural features in all edge detection methods.
      PubDate: Fri, 01 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac005
      Issue No: Vol. 19, No. 2 (2022)
       
  • Seismic random noise attenuation based on adaptive nonlocal median filter

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      Authors: Liu C; Guo L, Liu Y, et al.
      Pages: 157 - 166
      Abstract: AbstractThe accurate image of underground medium is determined by the quality of the seismic data, which can be improved by random noise attenuation and structural continuity enhancement. We proposed an adaptive nonlocal median filter that can protect geological structure while attenuating random noise. We combine the nonlocal idea with the weighted median filter and design the appropriate weights of the nonlocal median filter based on seismic data characteristics. The local structure is represented by the neighborhood around the center point. The directional difference of spatial vectors in the neighborhood is considered when computing the similarity. According to the local dip attribute of seismic data, the anisotropic Gaussian window is adaptively adjusted to increase the constraint along the structural direction. The proposed method can search more precisely for points with similar local structure to the filtered points and effectively attenuate seismic random noise. The continuity of events is enhanced while the goal of protecting fault information is achieved. The experimental results of the theoretical model and field data show that the adaptive nonlocal median filter can strike a balance between preserving structure information and attenuating seismic random noise.
      PubDate: Fri, 01 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac007
      Issue No: Vol. 19, No. 2 (2022)
       
  • Frequency information extraction based on time-frequency ridges for
           characterizing thin sand bodies

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      Authors: Liu L; Guan M, Zhang X, et al.
      Pages: 167 - 177
      Abstract: AbstractTime-frequency analysis (TFA) is a widely used reservoir prediction technology. During the identification of sand bodies using TFA, abnormally high values in the high-frequency portion of the spectrum usually indicate the presence of thin sand bodies. However, owing to the complexity of the depositional environment, the spatial distribution of thin sand bodies is often variable, and multiple phases of sand bodies—superimposed on each other—can occur with uneven thicknesses. A frequency information extraction technique based on time-frequency ridges (TFRs) is proposed in this study to identify stable TFRs in the time-frequency spectrum of a rearranged smooth pseudo-Wigner–Ville distribution with high energy aggregation, as well as to extract the main- and high-frequency energy contents relative to them. To enhance the ability of these energy components to detect thin sand bodies, a frequency-energy weighting factor is computed. By performing the aforementioned steps, information about each frequency band can be obtained and a comprehensive depiction of sand bodies with different thicknesses achieved. It is concluded that by using the proposed method thin sand bodies such as small riverbeds can be effectively characterized using seismic data.
      PubDate: Tue, 05 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac008
      Issue No: Vol. 19, No. 2 (2022)
       
  • Phase arrival picking for bridging multi-source downhole microseismic data
           using deep transfer learning

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      Authors: Zhang Y; Leng J, Dong Y, et al.
      Pages: 178 - 191
      Abstract: AbstractThe phase arrival picking of the downhole microseismic dataset is a critical step in fracturing monitoring data processing. Recently, data-driven methods have been widely used in seismology studies, especially in seismic phase picking. The picking results heavily depend on whether large quantities of accurately labeled phase samples could be obtained to extract the characteristics of seismic waveforms. Also, there is a shortcoming of poor generalization ability in dealing with the cross-source transfer scenarios. In this paper, we propose a novel deep transfer learning method for microseismic phase arrival picking by fine-tuning one existing pretrained model based on a few phase samples. The pretrained model, which has been domain-adapted for phase picking, adopts 2D U-Net to both extract time and space features, thereby improving the overall picking accuracy. Moreover, the fully convolutional U-Net architecture has the ability to handle samples with variable sizes so could be used for bridging downhole microseismic data from different sources. The results of two transfer cases show that compared with the direct application of the pretrained model and a newly trained model, the proposed method could provide more satisfactory performance with only limited seismic phase samples. Also, our method significantly reduces the cost of labeling and saves time because of avoiding repeated training.
      PubDate: Tue, 05 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac009
      Issue No: Vol. 19, No. 2 (2022)
       
  • High-efficiency and precision VSP wavefield separation method via DCT

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      Authors: Duan J; Zhang G, Liang C, et al.
      Pages: 192 - 210
      Abstract: AbstractThe processing efficiency of the widely used time-space (t-x) domain vertical seismic profiling (VSP) wavefield separation methods (such as median and singular value decomposition filtering) via one-dimensional discrete Fourier transform (DFT) depends on the wavefield separation method (or algorithm with processing parameter) and the total number of samples in the input VSP data. Once the wavefield separation method is determined, its processing efficiency is set and cannot be optimized. Although the popular frequency-wavenumber (f-k) domain VSP wavefield separation method via two-dimensional DFT has higher processing efficiency than the t-x domain VSP wavefield separation methods, its processing precision is susceptible to the spatial alias and Gibbs effects. For efficiency and precision improvements, we introduced the discrete cosine transform (DCT) operation into VSP wavefield separation for the first time, and proposed a high-efficiency and precision frequency-space (f-x) domain VSP wavefield separation method via DFT and DCT, in which the wavefield separation efficiency and precision can be optimized using the effective bandwidth cutoff frequency of the input VSP data. Based on the relationship between DFT and DCT, we combined their operations in the proposed method into one step (referred to as DCT–DFT) for further efficiency enhancement, thereby designing a high-efficiency and precision f-x domain VSP wavefield separation method via DCT–DFT. Theory analysis and synthetic and field VSP data examples show that the proposed method is highly efficient and precise, and can be widely used for three-dimensional (3D)-VSP data wavefield separation, especially for large distributed acoustic sensing (DAS)-VSP data.
      PubDate: Tue, 05 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac010
      Issue No: Vol. 19, No. 2 (2022)
       
  • The quantitative characterization of hydraulic fracture connectivity from
           a postmortem investigation

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      Authors: Jayawickrama E; Muto J, Sasaki O, et al.
      Pages: 211 - 226
      Abstract: AbstractTwo bio-siliceous Onnagawa (ONG I and ONG II) shale samples have been hydraulically fractured under two constant differential stresses (60 and 85 MPa, respectively) to investigate the fracture network's connectivity evolution by a postmortem analysis. The pressure inside the drilled borehole in a cylindrical core sample is increased above the confining pressure (10 MPa) until failure by hydraulic fracture. The two samples failed at two different borehole pressures (ONG I: 42 MPa, ONG II: 16 MPa). Fractured samples were scanned in an industrial X-ray CT machine and the tomographic images of the fracture network were extracted for a postmortem investigation. From the fracture volume segments, obtained by thresholding the frequency distribution of the fracture network's voxel values, a quantitative estimation of fracture connectivity was carried out. The connectivity was quantified based on the relative entropy of size distribution of fractures (${H_r}$), a method adapted from information theory. Fracture connectivity estimation shows that ${H_r}$ is at a maximum value when the fractures show a significant distribution with very limited connectivity. The value of ${H_r}$ is at a minimum and close to 0 when a well-linked fracture network is formed. In both samples, this minimum was attained at the threshold of 43k indicating the highest connectivity and the best representation of the fracture network. The extracted fracture network of ONG I showed a multi-winged hydraulic fracture network while a planar conventional two-winged hydraulic fracture network had been generated in ONG II with a lower fracture volume.
      PubDate: Tue, 05 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac012
      Issue No: Vol. 19, No. 2 (2022)
       
  • Long-term creep and microscopic deformation mechanisms of sandstone using
           

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      Authors: Bacha S; Huang B, Li H.
      Pages: 227 - 244
      Abstract: AbstractSince rock is heterogeneous, hence its behavior is always variable. The governing parameters in rock deformations are time, applied load, composition, water content, temperature and loading conditions including confinement and loading rate. Time-dependent deformation study is extremely important for the prevention of hazards such as rockburst, roof fall and collapse. In the current study, sandstone samples from Kouzidong Mine China are analyzed using long-term rheological creep tests and advanced microscopic scanning using 3D X-ray microscopy (XRM). Time is the main governing factor in rock rheological creep study. The current study focuses on the microscopic deformation of selected rock using rheological creep and microscopic analysis. Rock behaves differently under different applied loads; therefore, two different loads are applied on two sandstone samples. Two samples are scanned before and after rheological creep testing. The uniaxial constant load applied on the first sample is 40% of the uniaxial compressive strength of the rock (σ1 = 40%σc) for one month. The behavior of the first sample shows an instantaneous creep and stable creep. The maximum uniaxial strain is 0.0307. The scanning results show evidence of microfractures in sandstone sample 1 at a lower load. There is evidence of grain movement and boundary alteration. The grain movement depends on the bonding between different grains. The second sample is loaded at 50% the of uniaxial compressive strength (σ1 = 50%σc). The maximum uniaxial strain for sample 2 is 0.0408. Creep behavior is the same and the microscopic deformation is enhanced with increasing applied load.
      PubDate: Sat, 30 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac004
      Issue No: Vol. 19, No. 2 (2022)
       
  • Development and application of triangulation joint network based on an FEM
           program (RS2)

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      Authors: Xi P; Huo Y, Zhu D, et al.
      Pages: 245 - 254
      Abstract: AbstractIt is widely known that the triangle is the finest geometric unit, and therefore applying the triangulation joint to the rock mass simulation can not only accurately describe the fracture morphology of rock engineering, but also inversely deduce the mechanical parameters of blocks and joints. Based on the rock and soil two-dimensional analysis program (RS2), this paper compiles a program with MATLAB and realizes the parameterized setting of triangulation joint network (TJN) in RS2 for the first time, using it for the uniaxial compression model and roadway model accordingly. In the simulation of a RS2-TJN uniaxial compression model, its element parameters and joint parameters are calibrated according to the uniaxial compression strength and the elastic modulus obtained from the uniaxial compression test in a laboratory. Then its simulation results are compared with those of the particle flow code (PFC), which shows that the stress–strain curve obtained from the RS2-TJN uniaxial compression model matches the laboratory test one more closely. In the RS2-TJN roadway model, the simulation results obtained by adjusting the joint density are in good agreement with the roadway deformation in situ so as to study the failure characteristics of roadway surrounding rocks. Since the research on adding the triangulation joint network (cracks) to RS2 has not been found, its development and the realization of the parameterized control in this paper enrich the joint base of RS2 and provide a reference for the variety of joint numerical model.
      PubDate: Sat, 30 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac013
      Issue No: Vol. 19, No. 2 (2022)
       
  • Full-time domain matching pursuit and empirical mode decomposition based
           sparse fixed-point seismic inversion

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      Authors: Pei S; Yin X, Li K.
      Pages: 255 - 268
      Abstract: AbstractSparse seismic inversion is wildly utilized for reservoir prediction and resolution improvement. Matching pursuit (MP) is an effective algorithm for solving L0-norm and obtaining sparse inversion results. Sparse seismic inversion based on MP (MPSI) can estimate the sparse parameters of subsurface from observations by controlling the iterations and threshold. However, the low convergence and stability limit the application of MPSI. To accelerate the convergence of MP, the full-time domain matching pursuit (FTMP) algorithm is first proposed. The seismic inversion based on FTMP can realize the multi-point inversion simultaneously instead of searching the inversion results one by one, which is the process of MPSI. Also, the prior model constraint is then involved in the objective function to improve the stability and the layer-boundary fidelity of the inversion results. Furthermore, the empirical mode decomposition (EMD) algorithm is introduced into inversion framework to recover the features of the seismic signal from the noisy seismic signal. The fixed-point (FP) algorithm is adopted to solve the objective function in this study. The optimal inversion results can be estimated after finite iterations by the FP algorithm. Combining the FTMP sparse seismic inversion framework, prior model constraint, EMD and FP algorithms, a complete sparse seismic inversion method named the full-time domain matching pursuit-based sparse fixed-point seismic inversion is ultimately proposed. The synthetic and field examples are utilized to demonstrate the stability and practicality of this approach. Compared with MPSI, the inversion results of the proposed method have higher resolution and fidelity of the layer-boundary.
      PubDate: Sat, 30 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac014
      Issue No: Vol. 19, No. 2 (2022)
       
  • High-frequency wavefield extrapolation using the Fourier neural operator

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      Authors: Song C; Wang Y.
      Pages: 269 - 282
      Abstract: AbstractIn seismic wave simulation, solving the wave equation in the frequency domain requires calculating the inverse of the impedance matrix. The total cost strictly depends on the number of frequency components that are considered, if using a finite-difference method. For the applications such as seismic imaging and inversion, high-frequency information is always required and thus the wave simulation is always a challenging task as it demands tremendous computational cost for obtaining dispersion-free high-frequency wavefields for large subsurface models. This paper demonstrates that a data-driven machine learning method, called the Fourier neural operator (FNO), is capable of predicting high-frequency wavefields, based on a limited number of low-frequency components. As the FNO method is for the first time applied to seismic wavefield extrapolation, the experiment reveals three attractive features with FNO: high efficiency, high accuracy and, importantly, the predicted high-frequency wavefields are dispersion free.
      PubDate: Sat, 30 Apr 2022 00:00:00 GMT
      DOI: 10.1093/jge/gxac016
      Issue No: Vol. 19, No. 2 (2022)
       
 
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