Geofluids最新文献

{"title":"A New Mathematical Model for Flow and Heat Transfer of Dual-String Steam Injection in SAGD","authors":"Qiuying Du,&nbsp;Lili Cao,&nbsp;Wenfang Song,&nbsp;Mengyun Zhao,&nbsp;Hang Xu,&nbsp;Chuxiao Miao,&nbsp;Qingjun Du","doi":"10.1155/gfl/1587584","DOIUrl":"https://doi.org/10.1155/gfl/1587584","url":null,"abstract":"<p>Uneven steam distribution along horizontal wellbores, particularly the disparity between the heel and toe, poses a significant challenge in steam injection for heavy oil recovery. This often leads to asymmetric steam chamber development and premature steam channeling, severely limiting process efficiency. This study investigates the efficacy of a dual-string steam injection system designed to deliver steam simultaneously to both the heel and toe sections, thereby promoting a more balanced conformance. A comprehensive mathematical model coupling steam flow and heat transfer within the parallel dual-string completion of a heavy oil horizontal well was developed. The model, solved using a nodal analysis method, simulates transient wellbore parameters and steam reflux dynamics. A systematic parametric analysis evaluated the impact of injection time, steam velocity (0.5–2.5 m/s), temperature (400–550 K), and steam quality (0.995–0.999) on annular flow properties. The results confirm that the dual-string design effectively mitigates heel–toe effects and reduces the tendency for steam override and channeling. Wellbore heat loss was found to be highly sensitive to injection temperature and steam quality. An optimized injection strategy was identified: a velocity of 2 m/s, a temperature of 227°C, and a steam quality of 0.999 collectively achieved superior thermal efficiency, minimized energy loss, and enhanced overall injection performance. This work provides practical insights for optimizing completion design and operational parameters to improve the economic viability of thermal recovery in heavy oil reservoirs.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/1587584","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148324039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Modeling Full-Stage Rock Creep: A Perzyna Viscoplastic Approach Incorporating Damage and Strain Energy Theory","authors":"Xiaolong Zhang,&nbsp;Shutian Zhao,&nbsp;Wenbo Liu,&nbsp;Shuguang Zhang","doi":"10.1155/gfl/8604857","DOIUrl":"https://doi.org/10.1155/gfl/8604857","url":null,"abstract":"<p>Under high-level stress, the internal damage of rock accumulates over time, leading to significant nonlinearity in creep. However, traditional linear element combination models struggle to describe the creep behavior of rock in the accelerated creep stage. The creep mechanism is analyzed from the perspective of internal energy, and a new creep model is constructed based on strain energy theory by integrating Perzyna′s viscoplastic theory and the Nishihara model. This model can accurately characterize the full-process curves of the three creep stages: primary creep, steady-state creep, and accelerating creep. The one-dimensional and three-dimensional creep constitutive equations of the model are derived. The results show that the nonlinear viscoelastic-plastic rheological model has a correlation coefficient exceeding 0.95 with creep test data. It can precisely describe the primary and steady-state creep of rock under low stress, and more accurately reflect the accelerating creep characteristics under high stress. The established creep model overcomes the defect that the Nishihara model cannot describe accelerating creep. Meanwhile, a viscoplastic strain expression based on Perzyna′s viscoplastic theory is established to more accurately characterize accelerating creep. The research findings provide a new approach for studying the creep fracture process of rock.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/8604857","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148282151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Seismic Rock Physics Inversion With Varying Pore Structure Parameters and Consolidation Parameter in Tight Sandstone Reservoirs","authors":"Yongze Hu,&nbsp;Guangzhi Zhang,&nbsp;Zhenyu Zhu,&nbsp;Jie Li,&nbsp;Chonghang Bu,&nbsp;Xinke Zhao,&nbsp;Ziliang Luo","doi":"10.1155/gfl/1867876","DOIUrl":"https://doi.org/10.1155/gfl/1867876","url":null,"abstract":"<p>Tight sandstone gas holds significant exploration and development potential. However, its complex pore structure and heterogeneous consolidation make quantitative reservoir prediction challenging. In this study, we propose a novel seismic inversion method that incorporates consolidation parameter and pore structure parameters as constraints for enhanced rock physics modeling. By treating these parameters as depth-dependent variables, our approach captures the detailed lithological variations in tight sandstone reservoirs, leading to significantly improved accuracy in rock physics characterization. The model is integrated into a seismic reflection coefficient equation to establish a forward model, and a Bayesian inversion framework is used to directly predict reservoir property parameters from seismic data. Using the fast simulated annealing algorithm, pore structure parameters and consolidation parameter are iteratively updated alongside reservoir properties, increasing the stability and reliability of the inversion results. Applied to tight sandstone gas reservoirs in the Shaximiao Formation of the Sichuan Basin, the method demonstrates a strong correlation with gas-bearing zones, showing that the rock physics model with consolidation and pore structure constraints can enhance the delineation of reservoir distribution.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/1867876","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148282112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Correction to “Numerical Analysis of the Three-Dimensional Stress Characteristics in the Construction of Small-Radius Curved Shield Tunnels”","authors":"","doi":"10.1155/gfl/9856074","DOIUrl":"https://doi.org/10.1155/gfl/9856074","url":null,"abstract":"<p>S. Shi, M. Song, L. Yang, Y. Chen and Z. Tong., “Numerical Analysis of the Three-Dimensional Stress Characteristics in the Construction of Small-Radius Curved Shield Tunnels”, <i>Geofluids</i> 2025 (2025): 5561972, 10.1155/gfl/5561972</p><p>Department of Geological and Hydraulic Engineering, College of Civil Engineering</p><p>Tongji University</p><p>This study was funded by the National Natural Science Foundation Project of China (No. 42277145) and Shanghai Municipal 2023 Annual “Scientific and Technological Innovation Action Plan” Special Project for Scientific and Technological Support of Carbon Peak and Carbon Neutrality (Grant No. 23DZ1202200).</p><p>We apologize for these errors.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/9856074","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148093717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Sedimentary Characteristics and Depositional Model of a Shallow-Water Braided Delta in the Enping Formation, Lufeng X Oilfield, Pearl River Mouth Basin, China","authors":"Xianghui Zhang,&nbsp;Qinghao Meng,&nbsp;Ye Gao,&nbsp;Rui Zhu,&nbsp;Jiajun Chen,&nbsp;Mengjiao Dou,&nbsp;Changmin Zhang","doi":"10.1155/gfl/1522519","DOIUrl":"https://doi.org/10.1155/gfl/1522519","url":null,"abstract":"<p>Based on core observations, well-log data, and 3D seismic attributes, this study integrates lithofacies analysis, log-facies interpretation, and seismic-facies delineation to investigate the sedimentary characteristics and depositional architecture of the Enping formation in the Lufeng X Oilfield, Pearl River Mouth Basin. The Enping formation is interpreted as a shallow-water braided delta system composed of distributary channels and interdistributary bays on the delta plain and underwater distributary channels, mouth bars, and interdistributary bays on the delta front. From the delta plain to the delta front, single-channel sand bodies evolve from vertically erosional stacking to lateral channel-stacking and isolated patterns, accompanied by decreasing channel scale, increasing channel number, and reduced connectivity. Seismic attribute calibration indicates that RMS amplitude responds positively to sand-prone intervals, whereas RGB spectral decomposition attributes help delineate facies boundaries. On this basis, the spatial distribution and evolutionary pattern of the Enping formation sedimentary system are reconstructed, and a shallow-water braided-delta depositional model with a dominant sediment source from the northeast is proposed. The results provide a geological basis for reservoir prediction and remaining-oil evaluation in the Paleogene interval of the Lufeng X Oilfield.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/1522519","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148073729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Hydrochemical Characteristics of High-Temperature Geothermal Fluids and Quantitative Assessment of Wellbore Scaling in the Yangbajain Geothermal Field, Tibet","authors":"Jin Li,&nbsp;Xiangyu Fan,&nbsp;Yufei Chen,&nbsp;Hongge Xiong,&nbsp;Xiantao Yu,&nbsp;Ming Xu,&nbsp;Yifeng Zhou","doi":"10.1155/gfl/1815397","DOIUrl":"https://doi.org/10.1155/gfl/1815397","url":null,"abstract":"<p>Severe calcium carbonate scaling occurs in the wellbores of high-temperature geothermal wells in the Yangbajain Geothermal Field. Based on sampling and laboratory analysis of the geothermal field, this study investigates the hydrogeochemical characteristics of the geothermal fluids, estimates the reservoir temperature, and reconstructs the bottom-hole fluid composition. Combined with field discharge tests and scaling characteristics, a prediction model for the flash horizon in the wellbore and a coupled quantitative evaluation model for calcium carbonate scaling are established to forecast the scaling location and amount. The results indicate that the shallow reservoir temperature is 190^°C ± 20^°C, with an initial pH between 5.3 and 6.7. The high-temperature geothermal water is of Na-Cl type, and the CO₂ in the geothermal fluid primarily originates from high-temperature decarbonation of deep metamorphic sedimentary rocks and marine carbonates. Higher CO₂ content leads to a greater scaling rate and amount. For the typical geothermal well ZK303, the predicted flash horizon is at a depth of 126.8 m, with the most severe scaling occurring 10–20 m above the flash horizon. The maximum scaling rate is 0.1214 mm/d, with scaling thicknesses of 0.85 mm (7 days) and 3.64 mm (30 days), and scaling amounts of 342.65 kg (7 days) and 1468.52 kg (30 days).</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/1815397","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148073734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"An Adaptive Response Surface Methodology for Determining Coal Pillar Width in Geologically Variable Longwall Panels","authors":"Sen Yang,&nbsp;Zhe He,&nbsp;Yang Xu,&nbsp;Xin Yu,&nbsp;Yuxin Yuan,&nbsp;Zhiwen Chen","doi":"10.1155/gfl/5775504","DOIUrl":"https://doi.org/10.1155/gfl/5775504","url":null,"abstract":"<p>Simulation-based approaches are increasingly vital for addressing complex design challenges in underground coal mining, a domain where longwall pillar design is critically challenged by geological variability, and conventional methods lack adaptive capacity. This study develops a responsive design framework integrating response surface methodology (RSM) and numerical simulation to determine optimal pillar width under variable burial depth, dip angle, and mining height. Based on a Box–Behnken experimental design and FLAC 3D simulations, quadratic models were established for roadway deformation and pillar stress concentration, showing excellent fit (<i>R</i>² &gt; 0.94). Pillar width is the most influential factor for both responses. Significant interaction effects were identified: widening pillars reduces depth-induced deformation but may cause stress concentration in deep zones; a threshold width of approximately 7–8 m exists, beyond which increasing mining height promotes stress dissipation; and simultaneous increases in mining height and burial depth synergistically amplify roof displacement. Field validation under challenging geological transitions (seam thickness: 7–15 m; dip: 18°–0°) confirmed the model’s reliability. Adjusting pillar width from 6 to 8 m reduced average roof deformation by approximately 50% while keeping stress concentration within safe limits. The proposed RSM-based approach provides a computationally efficient and practically adaptable alternative to conventional pillar design in geologically variable panels.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/5775504","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148070474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Controls of Tuffaceous Components and Dissolution Heterogeneity on Reservoir Quality in Wenchang Formation Sandstones, Pearl River Mouth Basin, South China Sea","authors":"Wanlin Li,&nbsp;Xiaoping Li,&nbsp;Min Li,&nbsp;Xiaofang Jiang,&nbsp;Qingyu Zhang,&nbsp;Jiajun Fu,&nbsp;Erfan Mohammadian,&nbsp;Zhejun Pan,&nbsp;Zuorong Chen,&nbsp;Mengdi Sun","doi":"10.1155/gfl/1794905","DOIUrl":"https://doi.org/10.1155/gfl/1794905","url":null,"abstract":"<p>The Huizhou–Lufeng Depression in the Pearl River Mouth Basin is a significant hydrocarbon accumulation zone, where tuffaceous materials exert critical control on the quality of Paleogene Wenchang Formation sandstone reservoirs. However, the role of alteration products derived from different tuffaceous types in governing porosity–permeability evolution remains poorly constrained. To address this issue, an integrated analytical approach was applied, including casting thin section petrography, x-ray diffraction, electron probe microanalysis, ⁴⁰Ar/³⁹Ar dating of authigenic illite, Wood′s metal impregnation, and field emission scanning electron microscopy. The results indicate that the tuffaceous materials are volcaniclastic in origin and can be classified into four genetic types. Reservoir quality is controlled by distinct diagenetic pathways associated with each type. The dissolution of ultrabasic tuff follows a constructive two-stage process, characterized by early laumontite precipitation and subsequent secondary dissolution. In contrast, dissolution of basic to intermediate tuff leads to the precipitation of quartz and chlorite, whereas alteration of acidic tuff is predominantly destructive, generating abundant kaolinite and illite. Overall, alteration of ultrabasic tuff significantly enhances both porosity and permeability. For basic and intermediate tuff, although dissolution increases porosity, the accompanying cementation of pores by chlorite and quartz reduces pore connectivity, resulting in a decoupling of porosity and permeability. By contrast, the alteration products of acidic tuff tend to clog pore spaces, thereby adversely affecting reservoir quality. This study provides a theoretical framework for understanding Paleogene reservoir evolution and offers practical criteria for identifying favorable exploration targets in the Pearl River Mouth Basin.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/1794905","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148065573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Coal–Rock Damage and Subsidence Control Technology in Deep-Mine Strip Mining Under Large Mining Heights","authors":"Jiang Shuyin,&nbsp;Guo Wenbing,&nbsp;Li Xingyu,&nbsp;Yang Jie,&nbsp;Ni Huining,&nbsp;Yang Chao,&nbsp;Chai Yixuan,&nbsp;Ma Qi","doi":"10.1155/gfl/6041445","DOIUrl":"https://doi.org/10.1155/gfl/6041445","url":null,"abstract":"<p>A comprehensive approach incorporating field measurements, theoretical analysis, and numerical simulations was adopted to determine the strip-mining parameters for mining under large mining heights in kilometer-deep coal seams and achieve protective mining. Theoretical predictions were performed in strip mining′s maximum permissible ranges for surface deformation variables according to relevant measurements from adjacent fully mined zones. These predictions′ accuracy was verified, followed by an investigation into surface tilt, curvature, horizontal deformation, plastic zone distribution in coal pillars, and stress evolution under different recovery rates and cut widths. Surface deformation parameters′ peak magnitudes progressively increased with higher recovery rates, with surface tilt being the dominant controlling factor. When the recovery rate remained constant, variations in cut width had a minimal impact on surface deformation′s extreme values. Coal pillars′ elastic core ratio exhibited a gradual increase with expanding cut width. Moreover, the reduction in the elastic core ratio during mining became less pronounced with larger cut widths. Coal pillars′ maximum vertical stress decreased with increasing cut width. Vertical stress distribution patterns along coal pillars transitioned from single-peak to double-peak configurations through a central platform phase as cut widths increased from 60 to 100 m. Optimal strip-mining parameters were determined as 100-m cut width and 100-m pillar width by integrating surface deformation characteristics, plastic zone distribution, and stress evolution in coal pillars. Industrial trials were conducted to validate the proposed scheme.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/6041445","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148097141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Experimental Study on Multiscale Evolution Mechanism of Coalbed Reservoir Properties in “Three-Low” CBM Reservoirs Modified by Chlorine Dioxide","authors":"Chaowen Hu,&nbsp;Ruifeng Huang,&nbsp;Huifeng Wang,&nbsp;Bo Pan,&nbsp;Xiaojie Yang,&nbsp;Yichao Li,&nbsp;Fulong Sun","doi":"10.1155/gfl/3718316","DOIUrl":"https://doi.org/10.1155/gfl/3718316","url":null,"abstract":"<p>Aiming at the “three-low” challenges (low permeability, low gas saturation, and low critical desorption-to-storage ratio [CDSR]) of Chinese coalbed methane (CBM) reservoir materials, this study adopted chlorine dioxide (ClO₂) chemical modification on long-flame, coking, and anthracite coal materials. Integrated macroseepage experiments with microscale characterization were used to quantify the regulation of key CBM parameters. Results show that ClO₂ simultaneously enhances permeability, gas saturation, and CDSR. Under optimal conditions, coking coal permeability rose from 0.62 to 4.85 mD (+682%); permeability of long-flame coal and anthracite increased by 15.0% and 8.9%, respectively. Average gas saturation of the three ranks increased by 18.7%–25.3%, and critical desorption pressure dropped by 15.6%–22.3%. Microscopically, ClO₂ oxidizes coal materials to generate –OH and –COOH groups (peak areas +38.5%–46.2%) and dissolves clay minerals (kaolinite content −10.8%–14.5%), thereby widening fractures and refining pores. Coal rank responses differ: Anthracite requires 3.0% ClO₂ for 36 h, whereas long-flame coal reaches optimum at 2.0% ClO₂ for 24 h. The findings demonstrate that ClO₂ can overcome the limitations of conventional stimulation techniques and provide a practical pathway for efficient development of “three-low” CBM reservoirs in China.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2026 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/gfl/3718316","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148097134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}