The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average a...The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.展开更多
The implementation of Countermeasure Techniques(CTs)in the context of Network-On-Chip(NoC)based Multiprocessor System-On-Chip(MPSoC)routers against the Flooding Denial-of-Service Attack(F-DoSA)falls under Multi-Criter...The implementation of Countermeasure Techniques(CTs)in the context of Network-On-Chip(NoC)based Multiprocessor System-On-Chip(MPSoC)routers against the Flooding Denial-of-Service Attack(F-DoSA)falls under Multi-Criteria Decision-Making(MCDM)due to the three main concerns,called:traffic variations,multiple evaluation criteria-based traffic features,and prioritization NoC routers as an alternative.In this study,we propose a comprehensive evaluation of various NoC traffic features to identify the most efficient routers under the F-DoSA scenarios.Consequently,an MCDM approach is essential to address these emerging challenges.While the recent MCDM approach has some issues,such as uncertainty,this study utilizes Fuzzy-Weighted Zero-Inconsistency(FWZIC)to estimate the criteria weight values and Fuzzy Decision by Opinion Score Method(FDOSM)for ranking the routers with fuzzy Single-valued Neutrosophic under names(SvN-FWZIC and SvN-FDOSM)to overcome the ambiguity.The results obtained by using the SvN-FWZIC method indicate that the Max packet count has the highest importance among the evaluated criteria,with a weighted score of 0.1946.In contrast,the Hop count is identified as the least significant criterion,with a weighted score of 0.1090.The remaining criteria fall within a range of intermediate importance,with enqueue time scoring 0.1845,packet count decremented and traversal index scoring 0.1262,packet count incremented scoring 0.1124,and packet count index scoring 0.1472.In terms of ranking,SvN-FDOSM has two approaches:individual and group.Both the individual and group ranking processes show that(Router 4)is the most effective router,while(Router 3)is the lowest router under F-DoSA.The sensitivity analysis provides a high stability in ranking among all 10 scenarios.This approach offers essential feedback in making proper decisions in the design of countermeasure techniques in the domain of NoC-based MPSoC.展开更多
Flooding in rice fields,especially in coastal regions and low-lying river basins,causes significant devastation to crops.Rice is highly susceptible to prolonged flooding,with a drastic decline in yields if inundation ...Flooding in rice fields,especially in coastal regions and low-lying river basins,causes significant devastation to crops.Rice is highly susceptible to prolonged flooding,with a drastic decline in yields if inundation persists for more than 7 d,especially during the reproductive stage.Although the SUB1 QTL,which confers tolerance to complete submergence during the vegetative stage,has been incorporated into breeding programs,the development of alternative sources is crucial.These alternatives would broaden the genetic base,mitigate the influence of the genomic background,and extend the efficacy of SUB1 QTL to withstand longer submergence periods(up to approximately 21 d).Contemporary breeding strategies predominantly target submergence stress at the vegetative stage.However,stagnant flooding(partial submergence of vegetative parts)during the reproductive phase inflicts severe damage on the rice crop,leading to reduced yields,heightened susceptibility to pests and diseases,lodging,and inferior grain quality.The ability to tolerate stagnant flooding can be ascribed to several adaptive traits:accelerated aerenchyma formation,efficient underwater photosynthesis,reduced radial oxygen loss in submerged tissues,reinforced culms,enhanced reactive oxygen species scavenging within cells,dehydration tolerance post-flooding,and resistance to pests and diseases.A thorough investigation of the genetics underlying these traits,coupled with the integration of key alleles into elite genetic backgrounds,can significantly enhance food and income security in flood-prone rice-growing regions,particularly in coastal high-rainfall areas and low-lying river basins.This review aims to delineate an innovative breeding strategy that employs genomic,phenomic,and traditional breeding methodologies to develop rice varieties resilient to various dimensions of flooding stress at both the vegetative and reproductive stages.展开更多
Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance...Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance water and nutrient uptake.This study investigates the growth and yield of rice with both SUB1A and DRO1 in the background of IR64,under early-season flooding,and mid-season drought.The study used a randomized complete design with two factors:soil moisture treatments(submergence,drought,and their combination)and genotypes.The genotypes included IR64,and three near-isogenic lines(NILs):NIL-SUB1DRO1,NIL-SUB1,and NIL-DRO1.Complete submergence was imposed for 7 days on 14-day-old seedlings,while drought was imposed on control and submerged plants following a 21-day recovery period from submergence,using 42-day-old plants.Variables were measured before and after treatments(submergence and drought),and at harvest or grain maturity.The stresses negatively affected the genotypes.At harvest,IR64 and NIL-SUB1DRO1 under both stresses showed a significant reduction in tiller numbers,shoot dry weights,and yields compared to their control plants.IR64 exhibited a significant delay in reaching flowering under all stresses.The rice introgression lines showed significant improvements in tolerance to the stresses.The study showed no negative consequences of combining drought and submergence tolerance in rice.展开更多
Extensive flooding swept across large areas of Central Asia,mainly over Kazakhstan and southwestern Russia,from late March to April 2024.It was reported to be the worst flooding in the area in the past 70 years and ca...Extensive flooding swept across large areas of Central Asia,mainly over Kazakhstan and southwestern Russia,from late March to April 2024.It was reported to be the worst flooding in the area in the past 70 years and caused widespread devastation to society and infrastructure.However,the drivers of this record-breaking flood remain unexplored.Here,we show that the record-breaking floods were contributed by both long-term climate warming and interannual variability,with multiple climatic drivers at play across the synoptic to seasonal timescales.First,the heavy snowmelt in March 2024 was associated with above-normal preceding winter snow accumulation.Second,extreme rainfall was at a record-high during March 2024,in line with its increasing trend under climate warming.Third,the snowmelt and extreme rainfall in March were compounded by record-high soil moisture conditions in the preceding winter,which was a result of interannual variability and related to excessive winter rainfall over Central Asia.As climate warming continues,the interplay between the increasing trend of extreme rainfall,interannual variations in soil moisture pre-conditions,as well as shifting timing and magnitudes of spring snowmelt,will further increase and complicate spring flooding risks.This is a growing and widespread challenge for the mid-to high-latitude regions.展开更多
Flooding can lead to oxygen deprivation in rapeseed,negatively affecting its growth and development and ul-timately reducing yields.Vitreoscilla hemoglobin(VHb),a bacterial hemoglobin with a high oxygen-binding affini...Flooding can lead to oxygen deprivation in rapeseed,negatively affecting its growth and development and ul-timately reducing yields.Vitreoscilla hemoglobin(VHb),a bacterial hemoglobin with a high oxygen-binding affinity,plays a key role in enhancing oxygen uptake and metabolic efficiency under low-oxygen conditions.Through genetic transformation,we overexpressed the VHb gene in rapeseed,which resulted in significant im-provements in survival rate,root length,and biomass under submerged conditions.Additionally,we observed that transgenic plants developed adventitious roots in response to submergence stress.These transgenic plants also exhibited increased activities of ethanol dehydrogenase and pyruvate decarboxylase-enzymes associated with anaerobic respiration.Our findings indicate that VHb enhances flooding tolerance in rapeseed by promoting adventitious root formation and strengthening the plant's capacity for fermentation metabolism under anaerobic conditions.展开更多
Urban flooding in low-lying coastal regions(LCRs)is intensifying due to climate change and sea-level rise;however,the complex interplay of hydrological,climatic,and anthropogenic drivers remains poorly understood.This...Urban flooding in low-lying coastal regions(LCRs)is intensifying due to climate change and sea-level rise;however,the complex interplay of hydrological,climatic,and anthropogenic drivers remains poorly understood.This study investigates the specific meteo-hydrological factors linking climate-induced changes and human activities to the urban flooding event in My Tho City,a vulnerable coastal city in Vietnam's Tien Giang Province,from February 9 to 12,2024.Analyzing historical meteo-hydrological data(rainfall,monsoon winds,river discharge,and water levels),we examined the contributing factors.Our findings reveal that the flooding was predominantly driven by the combination of high astronomical tidal levels and significant water surges.These surges were amplified by northeast monsoon circulation.This situation was compounded by critically low Mekong River discharge during the dry season,which enhanced the inland penetration of tidal effects.Rainfall during the period was minimal and did not contribute significantly.We utilized a filtering technique to differentiate between astronomical tides and non-tidal surges in the water level data.These results provide empirical evidence demonstrating that climate-driven sea-level influences(manifesting as high tides and surges)and anthropogenic alterations to river flow governed the urban flooding dynamics.The study underscores the urgent need for integrated adaptation solutions addressing the complex land-ocean interactions, particularly in the context ofclimate change and relative sea-level rise.展开更多
Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer...Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer solutions exhibit non-Newtonian and nonlinear flow behavior including shear thinning and shear thickening,polymer convection,diffusion,adsorption,retention,inaccessible pore volume,and reduced effective permeability.However,available well test model of polymer flooding wells generally simplifies these characteristics on pressure transient response,which may lead to inaccurate results.This work proposes a novel two-phase numerical well test model to better describe the polymer viscoelasticity and nonlinear flow behavior.Different influence factors that related to near-well blockage during polymer flooding process,including the degree of blockage(inner zone permeability),the extent of blockage(composite radius),and polymer flooding front radius are explored to investigate these impacts on bottom hole pressure responses.Results show that polymer viscoelasticity has a significant impact on the transitional flow segment of type curves,and the effects of near-well formation blockage and polymer concentration distribution on well test curves are very similar.Thus,to accurately interpret the degree of near-well blockage in injection wells,it is essential to first eliminate the influence of polymer viscoelasticity.Finally,a field case is comprehensively analyzed and discussed to illustrate the applicability of the proposed model.展开更多
To address the water sensitivity of conglomerate reservoirs,a series of core sensitivity tests were conducted to evaluate the effects of varying ionic content.These findings serve as a foundation for improving reservo...To address the water sensitivity of conglomerate reservoirs,a series of core sensitivity tests were conducted to evaluate the effects of varying ionic content.These findings serve as a foundation for improving reservoir fluid dynamics and optimizing the concentration of anti-swelling agents in water flooding operations.The experiments revealed a marked disparity in response between cores with differing permeabilities.In Core No.5,characterized by low permeability,a 0.5% anti-swelling agent achieved only a modest 7.47% reduction in water sensitivity.Conversely,in the higher-permeability Core No.8,a 5%anti-swelling agent significantly reduced the water sensitivity index by 44.84% while enhancing permeability.Further,two displacement strategies-gas flooding following water flooding and water flooding after gas injection-were tested to assess the potential of CO_(2)water-alternating-gas(WAG)displacement.CO_(2)injection after water flooding in Core No.5 increased oil recovery by 9.24%,though gas channeling,evidenced by a sharp rise in the gas-liquid ratio,emerged as a critical concern.In Core No.8,water flooding following gas injection failed to improve recovery,likely due to pronounced water sensitivity,reduced permeability,and the formation of dominant flow channels under high displacement pressure,which limited sweep efficiency.展开更多
Oilfields worldwide are increasingly grappling with challenges such as early water breakthrough and high water production,yet direct,targeted solutions remain elusive.In recent years,chemical flooding techniques desig...Oilfields worldwide are increasingly grappling with challenges such as early water breakthrough and high water production,yet direct,targeted solutions remain elusive.In recent years,chemical flooding techniques designed for tertiary oil recovery have garnered significant attention,with microgel flooding emerging as a particularly prominent area of research.Despite its promise,the complex mechanisms underlying microgel flooding have been rarely investigated numerically.This study aims to address these gaps by characterizing the distribution of microgel concentration and viscosity within different pore structures.To enhance the accuracy of these characterizations,the viscosity of microgels is adjusted to account for the shear effects induced by flow rate and the swelling effects driven by salinity variations.The absolute permeability of the rock and the relative permeability of both oil and microgel are also analyzed to elucidate the mechanisms of microgel flooding.Additionally,a connectivity model is employed to achieve a quantitative representation of fluid flow capacity.The proposed model is validated through conceptual examples and applied to real oilfield blocks,demonstrating its accuracy and practical applicability.展开更多
Soil microorganisms and labile soil organic carbon(SOC)fractions are essential factors affecting greenhouse gas(GHG)emissions in paddy fields.However,the effects of labile SOC fractions and microorganisms on GHG emiss...Soil microorganisms and labile soil organic carbon(SOC)fractions are essential factors affecting greenhouse gas(GHG)emissions in paddy fields.However,the effects of labile SOC fractions and microorganisms on GHG emissions from flooding to drying after organic fertilizer replacing for chemical fertilizer remain unclear.Here,a long-term experiment was conducted with four treatments:chemical fertilization only(control),organic fertilizer substituting 25%of chemical N fertilizer(NM1),50%of chemical N fertilizer(NM2),and NM2combined with crop straw(NMS).GHG emissions were monitored,and soil samples were collected to determine labile SOC fractions and microorganisms.Results revealed the GHG emissions in the NM2 significantly increased by 196.88%from flooding to drying,mainly due to the higher CO_(2) emissions.The GHG emissions per kg of C input in NMS was the lowest with the value of 9.17.From flooding to drying,organic fertilizer application significantly increased the readily oxidizable organic carbon(ROC)contents and C lability;the NM2 and NMS dramatically increased the SOC and non-readily oxidizable organic carbon(NROC).The bacterial communities showed significant differences among different treatments in the flooding,while the significant difference was only found between the NMS and other treatments in the drying.From flooding to drying,changing soil moisture conditions causes C fractions and microbial communities to jointly affect carbon emissions,and the NMS promoted carbon sequestration and mitigated GHG emissions.Our findings highlight the importance of the labile SOC fractions and microorganisms linked to GHG emissions in paddy fields.展开更多
【Objective】Jatropha curcas is a potential source of biodiesel plant grown on waste and unattended lands,and parts of the areas are often suffered from flooding.The present study was conducted to develop a model to c...【Objective】Jatropha curcas is a potential source of biodiesel plant grown on waste and unattended lands,and parts of the areas are often suffered from flooding.The present study was conducted to develop a model to calculate the net CO_(2)assimilation rate,transpiration rate and stomatal conductance with respect to leaf position,which affect the J.curcas productivity under soil flooding.【Method】The process of developing mathematical models for physiological responses associated with parameterization,optimization and validation.The concept was applied for the calculation of net CO 2 assimilation rate from transpiration rate and stomatal conductance,transpiration rate from net CO_(2)assimilation rate and stomatal conductance,and stomatal conductance from net CO_(2)assimilation rate and transpiration rate in different leaf positions of J.curcas.The models were tested under soil flooding and normal conditions to suffice its wider applicability.A model was proposed to calculate net CO 2 assimilation rate,transpiration rate and stomatal conductance responses from a known set of response function data by calculating a transformation characteristic constant between any two possible paired response functions.【Result】The mean deviations and root mean square errors(RMSE)of calculated physiological responses were low,which validated the proposed hypothesis and statistical models.The approach was applied for modeling physiological responses successfully in J.curcas.RMSE ranged from1.69%to 11.17%when transpiration rate and stomatal conductance were transformed to net CO_(2)assimilation rate,and from 1.70%to 11.61%in case net CO_(2)assimilation rate and stomatal conductance were transformed to transpiration rate,and from 3.87%to 13.21%if net CO_(2)assimilation rate and transpiration rate were transformed to stomatal conductance,respectively.【Conclusion】The model can be useful for calculating cumulative responses under different conditions from a basic known set of data.The key to successful physiological models is finding the better options that are realistic,easy to understand,interpretative and practical between adherence to reality,comprehensibility,interpretative value,and practical usefulness on sustainable agriculture in years to come.展开更多
China boasts abundant heavy oil resources,which is vital for its energy security.However,its heavy oil typically exhibits high viscosity,which severely hinders its flow and extraction.Enhancing heavy oil flowability i...China boasts abundant heavy oil resources,which is vital for its energy security.However,its heavy oil typically exhibits high viscosity,which severely hinders its flow and extraction.Enhancing heavy oil flowability is vital for its effective exploitation.This study independently developed a visualization experimental system and explored the mechanisms through which combined thermal flooding(a combination of heat,chemical agents and gas)enhances heavy oil flowability.Results indicate that combined thermal flooding,that is,synergistically integrating heat,chemical agents,and gas,can effectively enhance the recovery of heavy oil by improving its flowability.Its working mechanisms were explored from the aspects of thermal effects,emulsification,precursor film,profile control capacity,and CO_(2) solution and extraction effects.The emulsification was observed using a confocal laser scanning fluorescence microscope(CLSFM).Findings reveal that steam flooding can boost crude oil flowability by augmenting temperature,while a chemical system tends to produce low-viscosity oil-in-water emul-sions,thus further aiding the flow of crude oil.During CO_(2) flooding,the solvent initially reduced crude oil viscosity and formed foamy oil,followed by the pronounced component separation of the produced fluids in the later stage.This demonstrates the effectiveness of CO_(2) in viscosity reduction and component extraction.Additionally,the results of interfacial tension experiments indicate that surfactants can reduce the heavy oil's interfacial tension,fostering the formation of nano-scale precursor films.They can also thicken these films and diminish their spreading resistance,thus accelerating residual oil removal and promoting heavy oil production.This study further elaborated the mechanisms behind the combined thermal flooding's efficiency in enhancing heavy oil recovery,offering a theoretical foundation for its broader application.展开更多
Extensive research has been conducted on remaining oil in the Daqing Oilfield during high water cuts’late stage,but few studies have offered multi-level analyses from both macro and micro perspectives for remaining o...Extensive research has been conducted on remaining oil in the Daqing Oilfield during high water cuts’late stage,but few studies have offered multi-level analyses from both macro and micro perspectives for remaining oil under varying formation conditions and displacement methods.This article focuses on the remaining oil in the S,P,and G reservoirs of Daqing Oilfield by employing the frozen section analysis method on the cores from the S,P,and G oil layers.The research identifies patterns among them,revealing that the Micro Remaining Oil types in these cores primarily include pore surface thin film,corner,throat,cluster,intergranular adsorption,and particle adsorption.Among these,intergranular adsorption contains the highest amount of remaining oil(the highest proportion reaches 60%)and serves as the main target for development potential.The overall distribution pattern of the Micro Remaining Oil in the S,P,and G oil layers shows that as flooding intensity increases,the amount of free-state remaining oil gradually decreases,while bound-state remaining oil gradually increases.The study also examines eight typical coring wells for macroscopic remaining oil,finding four main types in the reservoir:interlayer difference,interlayer loss,interlayer interference,and injection-production imperfect types.Among these,the injection-production imperfect type has the highest remaining oil content and is the primary target for development potential.Analyzing the reservoir utilization status and oil flooding efficiency reveals that as water flooding intensifies,the oil displacement efficiency of the oil layer gradually decreases,while the efficiency of oil layer displacement improves.Strongly flooded cores exhibit less free-state remaining oil than weakly flooded cores,making displacement more challenging.This study aims to provide a foundation and support for the development of remaining oil in the S,P,and G oil layers.展开更多
Using the ultra-low permeability reservoirs in the L block of the Jiangsu oilfield as an example,a series of experiments,including slim tube displacement experiments of CO_(2)-oil system,injection capacity experiments...Using the ultra-low permeability reservoirs in the L block of the Jiangsu oilfield as an example,a series of experiments,including slim tube displacement experiments of CO_(2)-oil system,injection capacity experiments,and high-temperature,high-pressure online nuclear magnetic resonance(NMR)displacement experiments,are conducted to reveal the oil/gas mass transfer pattern and oil production mechanisms during CO_(2) flooding in ultra-low permeability reservoirs.The impacts of CO_(2) storage pore range and miscibility on oil production and CO_(2) storage characteristics during CO_(2) flooding are clarified.The CO_(2) flooding process is divided into three stages:oil displacement stage by CO_(2),CO_(2) breakthrough stage,CO_(2) extraction stage.Crude oil expansion and viscosity reduction are the main mechanisms for improving recovery in the CO_(2) displacement stage.After CO_(2) breakthrough,the extraction of light components from the crude oil further enhances oil recovery.During CO_(2) flooding,the contribution of crude oil in large pores to the enhanced recovery exceeds 46%,while crude oil in medium pores serves as a reserve for incremental recovery.After CO_(2) breakthrough,a small portion of the crude oil is extracted and carried into nano-scale pores by CO_(2),becoming residual oil that is hard to recover.As the miscibility increases,the CO_(2) front moves more stably and sweeps a larger area,leading to increased CO_(2) storage range and volume.The CO_(2) full-storage stage contributes the most to the overall CO_(2) storage volume.In the CO_(2) escape stage,the storage mechanism involves partial in-situ storage of crude oil within the initial pore range and the CO_(2) carrying crude oil into smaller pores to increase the volume of stored CO_(2).In the CO_(2) leakage stage,as crude oil is produced,a significant amount of CO_(2) leaks out,causing a sharp decline in the storage efficiency.展开更多
Based on the technological demands for significantly enhancing oil recovery and long-term CO_(2)sequestration in the lacustrine oil reservoirs of China,this study systematically reviews the progress and practices of C...Based on the technological demands for significantly enhancing oil recovery and long-term CO_(2)sequestration in the lacustrine oil reservoirs of China,this study systematically reviews the progress and practices of CO_(2)flooding and storage technologies in recent years.It addresses the key technological needs and challenges faced in scaling up the application of CO_(2)flooding and storage to mature,developed oil fields,and analyzes future development directions.During the pilot test phase(2006-2019),continuous development and application practices led to the establishment of the first-generation CO_(2)flooding and storage technology system for lacustrine reservoirs.In the industrialization phase(since 2020),significant advances and insights have been achieved in terms of confined phase behavior,storage mechanisms,reservoir engineering,sweep control,engineering process and storage monitoring,enabling the maturation of the second-generation CO_(2)flooding and storage theories and technologies to effectively support the demonstration projects of Carbon Capture,Utilization and Storage(CCUS).To overcome key technical issues such as low miscibility,difficulty in gas channeling control,high process requirements,limited application scenarios,and coordination challenges in CO_(2)flooding and storage,and to support the large-scale application of CCUS,it is necessary to strengthen research on key technologies for establishing the third-generation CO_(2)flooding and storage technological system incorporating miscibility enhancement and transformation,comprehensive regulation for sweep enhancement,whole-process engineering techniques and equipment,long-term storage monitoring safety,and synergistic optimization of flooding and storage.展开更多
The author affiliation and the funding information in the Acknowledgement section of the online version of the original article was revised.One affiliation(the 8th affiliation)of the first author is added.The Acknowle...The author affiliation and the funding information in the Acknowledgement section of the online version of the original article was revised.One affiliation(the 8th affiliation)of the first author is added.The Acknowledgement section of the original article has been revised to:Acknowledgments:This research was funded by the National University of Mongolia under grant agreement P2023(grant number P2023-4578)and supported by the Chey Institute for Advanced Studies“International Scholarship Exchange Fellowship for the academic year of 2024-2025”,Republic of Korea,and the National University of Mongolia.We would like to acknowledge the National University of Mongolia and Soumik Das from the Center for the Study of Regional Development,Jawaharlal Nehru University,New Delhi-110067,for his valuable assistance in preparing the geological maps.展开更多
To investigate the relationship between grain sizes, seepage capacity, and oil-displacement efficiency in the Liushagang Formation of the Beibuwan Basin, this study identifies the multistage pore-throat structure as a...To investigate the relationship between grain sizes, seepage capacity, and oil-displacement efficiency in the Liushagang Formation of the Beibuwan Basin, this study identifies the multistage pore-throat structure as a crucial factor through a comparison of oil displacement in microscopic pore-throat experiments. The two-phase flow evaluation method based on the Li-Horne model is utilized to effectively characterize and quantify the seepage characteristics of different reservoirs, closely relating them to the distribution of microscopic pores and throats. It is observed that conglomerate sandstones at different stages exhibit significant heterogeneity and noticeable differences in seepage capacity, highlighting the crucial role played by certain large pore throats in determining seepage capacity and oil displacement efficiency. Furthermore, it was found that the displacement effects of conglomeratic sandstones with strong heterogeneity were inferior to those of conventional homogeneous sandstone, as evidenced by multiple displacement experiments conducted on core samples with varying granularities and flooding systems. Subsequently, core-based experiments on associated gas flooding after water flooding were conducted to address the challenge of achieving satisfactory results in a single displacement mode for reservoirs with significant heterogeneity. The results indicate that the oil recovery rates for associated gas flooding after water flooding increased by 7.3%-16.4% compared with water flooding alone at a gas-oil ratio of approximately 7000 m^(3)/m^(3). Therefore, considering the advantages of gas flooding in terms of seepage capacity, oil exchange ratio, and the potential for two-phase production, gas flooding is recommended as an energy supplement mode for homogeneous reservoirs in the presence of sufficient gas source and appropriate tectonic angle. On the other hand, associated gas flooding after water flooding is suggested to achieve a more favorable development effect compared to a single mode of energy supplementation for strongly heterogeneous sandstone reservoirs.展开更多
Zero-valent iron(ZVI)is a promising material for the remediation of Cd-contaminated paddy soils.However,the effects of ZVI added during flooding or drainage processes on cadmium(Cd)retention remain unclear.Herein,Cd-c...Zero-valent iron(ZVI)is a promising material for the remediation of Cd-contaminated paddy soils.However,the effects of ZVI added during flooding or drainage processes on cadmium(Cd)retention remain unclear.Herein,Cd-contaminated paddy soil was incubated for 40days of flooding and then for 15 days of drainage,and the underlying mechanisms of Cd immobilization coupled with Fe/S/N redox processes were investigated.The addition of ZVI to the flooding process was more conducive to Cd immobilization.Less potential available Cd was detected by adding ZVI before flooding,which may be due to the increase in paddy soil pH and newly formed secondary Fe minerals.Moreover,the reductive dissolution of Fe minerals promoted the release of soil colloids,thereby increasing significantly the surface sites and causing Cd immobilization.Additionally,the addition of ZVI before flooding played a vital role in Cd retention after soil drainage.In contrast,the addition of ZVI in the drainage phase was not conducive to Cd retention,which might be due to the rapid decrease in soil pH that inhibited Cd adsorption and further immobilization on soil surfaces.The findings of this study demonstrated that Cd availability in paddy soil was largely reduced by adding ZVI during the flooding period and provide a novel insight into the mechanisms of ZVI remediation in Cd-contaminated paddy soils.展开更多
The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing ...The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing to insufficient evidence,the quantitative correlation between flooding and climate change remains illdefined.We present a long time series of maximum flood discharge in the YRB dating back to 1843 compiled from historical documents and instrument measurements.Variations in yearly maximum flood discharge show distinct periods:a dramatic decreasing period from 1843 to 1950,and an oscillating gentle decreasing from 1950 to 2021,with the latter period also showing increasing more extreme floods.A Mann-Kendall test analysis suggests that the latter period can be further split into two distinct sub-periods:an oscillating gentle decreasing period from 1950 to 2000,and a clear recent increasing period from 2000 to 2021.We further predict that climate change will cause an ongoing remarkable increase in future flooding risk and an∼44.4 billion US dollars loss of floods in the YRB in 2100.展开更多
基金supported by the National Natural Science Foundation of China(No.42072211)the National Natural Science Foundation of China(No.42401048)the Third Xinjiang Scientific Expedition and Research Program(No.2021xjkk0302)。
文摘The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.
文摘The implementation of Countermeasure Techniques(CTs)in the context of Network-On-Chip(NoC)based Multiprocessor System-On-Chip(MPSoC)routers against the Flooding Denial-of-Service Attack(F-DoSA)falls under Multi-Criteria Decision-Making(MCDM)due to the three main concerns,called:traffic variations,multiple evaluation criteria-based traffic features,and prioritization NoC routers as an alternative.In this study,we propose a comprehensive evaluation of various NoC traffic features to identify the most efficient routers under the F-DoSA scenarios.Consequently,an MCDM approach is essential to address these emerging challenges.While the recent MCDM approach has some issues,such as uncertainty,this study utilizes Fuzzy-Weighted Zero-Inconsistency(FWZIC)to estimate the criteria weight values and Fuzzy Decision by Opinion Score Method(FDOSM)for ranking the routers with fuzzy Single-valued Neutrosophic under names(SvN-FWZIC and SvN-FDOSM)to overcome the ambiguity.The results obtained by using the SvN-FWZIC method indicate that the Max packet count has the highest importance among the evaluated criteria,with a weighted score of 0.1946.In contrast,the Hop count is identified as the least significant criterion,with a weighted score of 0.1090.The remaining criteria fall within a range of intermediate importance,with enqueue time scoring 0.1845,packet count decremented and traversal index scoring 0.1262,packet count incremented scoring 0.1124,and packet count index scoring 0.1472.In terms of ranking,SvN-FDOSM has two approaches:individual and group.Both the individual and group ranking processes show that(Router 4)is the most effective router,while(Router 3)is the lowest router under F-DoSA.The sensitivity analysis provides a high stability in ranking among all 10 scenarios.This approach offers essential feedback in making proper decisions in the design of countermeasure techniques in the domain of NoC-based MPSoC.
基金the University Grants Commission(UGC),Government of India for the UGC-Non-NET Fellowship during the PhD degree program(Grant No.R/Dev/IX-Sch/BHU-Res-Sch/2022-23/51137).
文摘Flooding in rice fields,especially in coastal regions and low-lying river basins,causes significant devastation to crops.Rice is highly susceptible to prolonged flooding,with a drastic decline in yields if inundation persists for more than 7 d,especially during the reproductive stage.Although the SUB1 QTL,which confers tolerance to complete submergence during the vegetative stage,has been incorporated into breeding programs,the development of alternative sources is crucial.These alternatives would broaden the genetic base,mitigate the influence of the genomic background,and extend the efficacy of SUB1 QTL to withstand longer submergence periods(up to approximately 21 d).Contemporary breeding strategies predominantly target submergence stress at the vegetative stage.However,stagnant flooding(partial submergence of vegetative parts)during the reproductive phase inflicts severe damage on the rice crop,leading to reduced yields,heightened susceptibility to pests and diseases,lodging,and inferior grain quality.The ability to tolerate stagnant flooding can be ascribed to several adaptive traits:accelerated aerenchyma formation,efficient underwater photosynthesis,reduced radial oxygen loss in submerged tissues,reinforced culms,enhanced reactive oxygen species scavenging within cells,dehydration tolerance post-flooding,and resistance to pests and diseases.A thorough investigation of the genetics underlying these traits,coupled with the integration of key alleles into elite genetic backgrounds,can significantly enhance food and income security in flood-prone rice-growing regions,particularly in coastal high-rainfall areas and low-lying river basins.This review aims to delineate an innovative breeding strategy that employs genomic,phenomic,and traditional breeding methodologies to develop rice varieties resilient to various dimensions of flooding stress at both the vegetative and reproductive stages.
文摘Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance water and nutrient uptake.This study investigates the growth and yield of rice with both SUB1A and DRO1 in the background of IR64,under early-season flooding,and mid-season drought.The study used a randomized complete design with two factors:soil moisture treatments(submergence,drought,and their combination)and genotypes.The genotypes included IR64,and three near-isogenic lines(NILs):NIL-SUB1DRO1,NIL-SUB1,and NIL-DRO1.Complete submergence was imposed for 7 days on 14-day-old seedlings,while drought was imposed on control and submerged plants following a 21-day recovery period from submergence,using 42-day-old plants.Variables were measured before and after treatments(submergence and drought),and at harvest or grain maturity.The stresses negatively affected the genotypes.At harvest,IR64 and NIL-SUB1DRO1 under both stresses showed a significant reduction in tiller numbers,shoot dry weights,and yields compared to their control plants.IR64 exhibited a significant delay in reaching flowering under all stresses.The rice introgression lines showed significant improvements in tolerance to the stresses.The study showed no negative consequences of combining drought and submergence tolerance in rice.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.42422502,42275038)the China Meteorological Administration Climate Change Special Program(Grant No.QBZ202306)。
文摘Extensive flooding swept across large areas of Central Asia,mainly over Kazakhstan and southwestern Russia,from late March to April 2024.It was reported to be the worst flooding in the area in the past 70 years and caused widespread devastation to society and infrastructure.However,the drivers of this record-breaking flood remain unexplored.Here,we show that the record-breaking floods were contributed by both long-term climate warming and interannual variability,with multiple climatic drivers at play across the synoptic to seasonal timescales.First,the heavy snowmelt in March 2024 was associated with above-normal preceding winter snow accumulation.Second,extreme rainfall was at a record-high during March 2024,in line with its increasing trend under climate warming.Third,the snowmelt and extreme rainfall in March were compounded by record-high soil moisture conditions in the preceding winter,which was a result of interannual variability and related to excessive winter rainfall over Central Asia.As climate warming continues,the interplay between the increasing trend of extreme rainfall,interannual variations in soil moisture pre-conditions,as well as shifting timing and magnitudes of spring snowmelt,will further increase and complicate spring flooding risks.This is a growing and widespread challenge for the mid-to high-latitude regions.
基金supported by National Key Research and Development Program of China(2023YFD1201403)The Science and Technology Innovation Program of Hunan Province(2023RC1077)+2 种基金Key Research and Development Projects of Hunan Provincial(2023NK2012)Hunan Provincial Science and Technology Talent Promotion Project(2023 TJ-Z09)The Hunan Agricultural Science and Technology Innovation Fund Project(2024CX096).
文摘Flooding can lead to oxygen deprivation in rapeseed,negatively affecting its growth and development and ul-timately reducing yields.Vitreoscilla hemoglobin(VHb),a bacterial hemoglobin with a high oxygen-binding affinity,plays a key role in enhancing oxygen uptake and metabolic efficiency under low-oxygen conditions.Through genetic transformation,we overexpressed the VHb gene in rapeseed,which resulted in significant im-provements in survival rate,root length,and biomass under submerged conditions.Additionally,we observed that transgenic plants developed adventitious roots in response to submergence stress.These transgenic plants also exhibited increased activities of ethanol dehydrogenase and pyruvate decarboxylase-enzymes associated with anaerobic respiration.Our findings indicate that VHb enhances flooding tolerance in rapeseed by promoting adventitious root formation and strengthening the plant's capacity for fermentation metabolism under anaerobic conditions.
基金supported by the Vietnam National University,Ho Chi Minh City(VNU-HCM)project entitled“Identifying and quantifying drivers causing water level fluctuations in the Vietnamese Mekong Delta”grant number[B2024-18-01].
文摘Urban flooding in low-lying coastal regions(LCRs)is intensifying due to climate change and sea-level rise;however,the complex interplay of hydrological,climatic,and anthropogenic drivers remains poorly understood.This study investigates the specific meteo-hydrological factors linking climate-induced changes and human activities to the urban flooding event in My Tho City,a vulnerable coastal city in Vietnam's Tien Giang Province,from February 9 to 12,2024.Analyzing historical meteo-hydrological data(rainfall,monsoon winds,river discharge,and water levels),we examined the contributing factors.Our findings reveal that the flooding was predominantly driven by the combination of high astronomical tidal levels and significant water surges.These surges were amplified by northeast monsoon circulation.This situation was compounded by critically low Mekong River discharge during the dry season,which enhanced the inland penetration of tidal effects.Rainfall during the period was minimal and did not contribute significantly.We utilized a filtering technique to differentiate between astronomical tides and non-tidal surges in the water level data.These results provide empirical evidence demonstrating that climate-driven sea-level influences(manifesting as high tides and surges)and anthropogenic alterations to river flow governed the urban flooding dynamics.The study underscores the urgent need for integrated adaptation solutions addressing the complex land-ocean interactions, particularly in the context ofclimate change and relative sea-level rise.
基金supported by the National Natural Science Foundation of China(52104049)the Young Elite Scientist Sponsorship Program by Beijing Association for Science and Technology(BYESS2023262)。
文摘Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer solutions exhibit non-Newtonian and nonlinear flow behavior including shear thinning and shear thickening,polymer convection,diffusion,adsorption,retention,inaccessible pore volume,and reduced effective permeability.However,available well test model of polymer flooding wells generally simplifies these characteristics on pressure transient response,which may lead to inaccurate results.This work proposes a novel two-phase numerical well test model to better describe the polymer viscoelasticity and nonlinear flow behavior.Different influence factors that related to near-well blockage during polymer flooding process,including the degree of blockage(inner zone permeability),the extent of blockage(composite radius),and polymer flooding front radius are explored to investigate these impacts on bottom hole pressure responses.Results show that polymer viscoelasticity has a significant impact on the transitional flow segment of type curves,and the effects of near-well formation blockage and polymer concentration distribution on well test curves are very similar.Thus,to accurately interpret the degree of near-well blockage in injection wells,it is essential to first eliminate the influence of polymer viscoelasticity.Finally,a field case is comprehensively analyzed and discussed to illustrate the applicability of the proposed model.
文摘To address the water sensitivity of conglomerate reservoirs,a series of core sensitivity tests were conducted to evaluate the effects of varying ionic content.These findings serve as a foundation for improving reservoir fluid dynamics and optimizing the concentration of anti-swelling agents in water flooding operations.The experiments revealed a marked disparity in response between cores with differing permeabilities.In Core No.5,characterized by low permeability,a 0.5% anti-swelling agent achieved only a modest 7.47% reduction in water sensitivity.Conversely,in the higher-permeability Core No.8,a 5%anti-swelling agent significantly reduced the water sensitivity index by 44.84% while enhancing permeability.Further,two displacement strategies-gas flooding following water flooding and water flooding after gas injection-were tested to assess the potential of CO_(2)water-alternating-gas(WAG)displacement.CO_(2)injection after water flooding in Core No.5 increased oil recovery by 9.24%,though gas channeling,evidenced by a sharp rise in the gas-liquid ratio,emerged as a critical concern.In Core No.8,water flooding following gas injection failed to improve recovery,likely due to pronounced water sensitivity,reduced permeability,and the formation of dominant flow channels under high displacement pressure,which limited sweep efficiency.
基金supported by the National Natural Science Foundation project“Micro-Scale Effect of Oil-Gas Flow and the Mechanism of Enhancing Shale Oil Recovery by Natural Gas Injection”(No.52074317)。
文摘Oilfields worldwide are increasingly grappling with challenges such as early water breakthrough and high water production,yet direct,targeted solutions remain elusive.In recent years,chemical flooding techniques designed for tertiary oil recovery have garnered significant attention,with microgel flooding emerging as a particularly prominent area of research.Despite its promise,the complex mechanisms underlying microgel flooding have been rarely investigated numerically.This study aims to address these gaps by characterizing the distribution of microgel concentration and viscosity within different pore structures.To enhance the accuracy of these characterizations,the viscosity of microgels is adjusted to account for the shear effects induced by flow rate and the swelling effects driven by salinity variations.The absolute permeability of the rock and the relative permeability of both oil and microgel are also analyzed to elucidate the mechanisms of microgel flooding.Additionally,a connectivity model is employed to achieve a quantitative representation of fluid flow capacity.The proposed model is validated through conceptual examples and applied to real oilfield blocks,demonstrating its accuracy and practical applicability.
基金the support of the National Natural Science Foundation of China(No.42107247)the National Key Research and Development Project(No.2022YFD1901605)+1 种基金the Natural Science Foundation of Sichuan Province(Nos.2025YFHZ0142 and 2024NSFSC0800)the Tobacco Science Foundation of Sichuan Province(No.SCYC202407)。
文摘Soil microorganisms and labile soil organic carbon(SOC)fractions are essential factors affecting greenhouse gas(GHG)emissions in paddy fields.However,the effects of labile SOC fractions and microorganisms on GHG emissions from flooding to drying after organic fertilizer replacing for chemical fertilizer remain unclear.Here,a long-term experiment was conducted with four treatments:chemical fertilization only(control),organic fertilizer substituting 25%of chemical N fertilizer(NM1),50%of chemical N fertilizer(NM2),and NM2combined with crop straw(NMS).GHG emissions were monitored,and soil samples were collected to determine labile SOC fractions and microorganisms.Results revealed the GHG emissions in the NM2 significantly increased by 196.88%from flooding to drying,mainly due to the higher CO_(2) emissions.The GHG emissions per kg of C input in NMS was the lowest with the value of 9.17.From flooding to drying,organic fertilizer application significantly increased the readily oxidizable organic carbon(ROC)contents and C lability;the NM2 and NMS dramatically increased the SOC and non-readily oxidizable organic carbon(NROC).The bacterial communities showed significant differences among different treatments in the flooding,while the significant difference was only found between the NMS and other treatments in the drying.From flooding to drying,changing soil moisture conditions causes C fractions and microbial communities to jointly affect carbon emissions,and the NMS promoted carbon sequestration and mitigated GHG emissions.Our findings highlight the importance of the labile SOC fractions and microorganisms linked to GHG emissions in paddy fields.
文摘【Objective】Jatropha curcas is a potential source of biodiesel plant grown on waste and unattended lands,and parts of the areas are often suffered from flooding.The present study was conducted to develop a model to calculate the net CO_(2)assimilation rate,transpiration rate and stomatal conductance with respect to leaf position,which affect the J.curcas productivity under soil flooding.【Method】The process of developing mathematical models for physiological responses associated with parameterization,optimization and validation.The concept was applied for the calculation of net CO 2 assimilation rate from transpiration rate and stomatal conductance,transpiration rate from net CO_(2)assimilation rate and stomatal conductance,and stomatal conductance from net CO_(2)assimilation rate and transpiration rate in different leaf positions of J.curcas.The models were tested under soil flooding and normal conditions to suffice its wider applicability.A model was proposed to calculate net CO 2 assimilation rate,transpiration rate and stomatal conductance responses from a known set of response function data by calculating a transformation characteristic constant between any two possible paired response functions.【Result】The mean deviations and root mean square errors(RMSE)of calculated physiological responses were low,which validated the proposed hypothesis and statistical models.The approach was applied for modeling physiological responses successfully in J.curcas.RMSE ranged from1.69%to 11.17%when transpiration rate and stomatal conductance were transformed to net CO_(2)assimilation rate,and from 1.70%to 11.61%in case net CO_(2)assimilation rate and stomatal conductance were transformed to transpiration rate,and from 3.87%to 13.21%if net CO_(2)assimilation rate and transpiration rate were transformed to stomatal conductance,respectively.【Conclusion】The model can be useful for calculating cumulative responses under different conditions from a basic known set of data.The key to successful physiological models is finding the better options that are realistic,easy to understand,interpretative and practical between adherence to reality,comprehensibility,interpretative value,and practical usefulness on sustainable agriculture in years to come.
基金The authors thank the National Natural Science Foundation of China(Grant No.U20B6003)for their financial support to carry out this research.
文摘China boasts abundant heavy oil resources,which is vital for its energy security.However,its heavy oil typically exhibits high viscosity,which severely hinders its flow and extraction.Enhancing heavy oil flowability is vital for its effective exploitation.This study independently developed a visualization experimental system and explored the mechanisms through which combined thermal flooding(a combination of heat,chemical agents and gas)enhances heavy oil flowability.Results indicate that combined thermal flooding,that is,synergistically integrating heat,chemical agents,and gas,can effectively enhance the recovery of heavy oil by improving its flowability.Its working mechanisms were explored from the aspects of thermal effects,emulsification,precursor film,profile control capacity,and CO_(2) solution and extraction effects.The emulsification was observed using a confocal laser scanning fluorescence microscope(CLSFM).Findings reveal that steam flooding can boost crude oil flowability by augmenting temperature,while a chemical system tends to produce low-viscosity oil-in-water emul-sions,thus further aiding the flow of crude oil.During CO_(2) flooding,the solvent initially reduced crude oil viscosity and formed foamy oil,followed by the pronounced component separation of the produced fluids in the later stage.This demonstrates the effectiveness of CO_(2) in viscosity reduction and component extraction.Additionally,the results of interfacial tension experiments indicate that surfactants can reduce the heavy oil's interfacial tension,fostering the formation of nano-scale precursor films.They can also thicken these films and diminish their spreading resistance,thus accelerating residual oil removal and promoting heavy oil production.This study further elaborated the mechanisms behind the combined thermal flooding's efficiency in enhancing heavy oil recovery,offering a theoretical foundation for its broader application.
文摘Extensive research has been conducted on remaining oil in the Daqing Oilfield during high water cuts’late stage,but few studies have offered multi-level analyses from both macro and micro perspectives for remaining oil under varying formation conditions and displacement methods.This article focuses on the remaining oil in the S,P,and G reservoirs of Daqing Oilfield by employing the frozen section analysis method on the cores from the S,P,and G oil layers.The research identifies patterns among them,revealing that the Micro Remaining Oil types in these cores primarily include pore surface thin film,corner,throat,cluster,intergranular adsorption,and particle adsorption.Among these,intergranular adsorption contains the highest amount of remaining oil(the highest proportion reaches 60%)and serves as the main target for development potential.The overall distribution pattern of the Micro Remaining Oil in the S,P,and G oil layers shows that as flooding intensity increases,the amount of free-state remaining oil gradually decreases,while bound-state remaining oil gradually increases.The study also examines eight typical coring wells for macroscopic remaining oil,finding four main types in the reservoir:interlayer difference,interlayer loss,interlayer interference,and injection-production imperfect types.Among these,the injection-production imperfect type has the highest remaining oil content and is the primary target for development potential.Analyzing the reservoir utilization status and oil flooding efficiency reveals that as water flooding intensifies,the oil displacement efficiency of the oil layer gradually decreases,while the efficiency of oil layer displacement improves.Strongly flooded cores exhibit less free-state remaining oil than weakly flooded cores,making displacement more challenging.This study aims to provide a foundation and support for the development of remaining oil in the S,P,and G oil layers.
基金Supported by the National Natural Science Foundation of China(52274053)Natural Science Foundation of Beijing(3232028).
文摘Using the ultra-low permeability reservoirs in the L block of the Jiangsu oilfield as an example,a series of experiments,including slim tube displacement experiments of CO_(2)-oil system,injection capacity experiments,and high-temperature,high-pressure online nuclear magnetic resonance(NMR)displacement experiments,are conducted to reveal the oil/gas mass transfer pattern and oil production mechanisms during CO_(2) flooding in ultra-low permeability reservoirs.The impacts of CO_(2) storage pore range and miscibility on oil production and CO_(2) storage characteristics during CO_(2) flooding are clarified.The CO_(2) flooding process is divided into three stages:oil displacement stage by CO_(2),CO_(2) breakthrough stage,CO_(2) extraction stage.Crude oil expansion and viscosity reduction are the main mechanisms for improving recovery in the CO_(2) displacement stage.After CO_(2) breakthrough,the extraction of light components from the crude oil further enhances oil recovery.During CO_(2) flooding,the contribution of crude oil in large pores to the enhanced recovery exceeds 46%,while crude oil in medium pores serves as a reserve for incremental recovery.After CO_(2) breakthrough,a small portion of the crude oil is extracted and carried into nano-scale pores by CO_(2),becoming residual oil that is hard to recover.As the miscibility increases,the CO_(2) front moves more stably and sweeps a larger area,leading to increased CO_(2) storage range and volume.The CO_(2) full-storage stage contributes the most to the overall CO_(2) storage volume.In the CO_(2) escape stage,the storage mechanism involves partial in-situ storage of crude oil within the initial pore range and the CO_(2) carrying crude oil into smaller pores to increase the volume of stored CO_(2).In the CO_(2) leakage stage,as crude oil is produced,a significant amount of CO_(2) leaks out,causing a sharp decline in the storage efficiency.
基金Supported by the China National Key R&D Program(2023YFF0614100)National Science and Technology Major Project of China(2024ZD14066)+1 种基金Major Project of PetroChina Company Limited(2021ZZ01)Key R&D Project of Xinjiang Uygur Autonomous Region of China(2024B03001).
文摘Based on the technological demands for significantly enhancing oil recovery and long-term CO_(2)sequestration in the lacustrine oil reservoirs of China,this study systematically reviews the progress and practices of CO_(2)flooding and storage technologies in recent years.It addresses the key technological needs and challenges faced in scaling up the application of CO_(2)flooding and storage to mature,developed oil fields,and analyzes future development directions.During the pilot test phase(2006-2019),continuous development and application practices led to the establishment of the first-generation CO_(2)flooding and storage technology system for lacustrine reservoirs.In the industrialization phase(since 2020),significant advances and insights have been achieved in terms of confined phase behavior,storage mechanisms,reservoir engineering,sweep control,engineering process and storage monitoring,enabling the maturation of the second-generation CO_(2)flooding and storage theories and technologies to effectively support the demonstration projects of Carbon Capture,Utilization and Storage(CCUS).To overcome key technical issues such as low miscibility,difficulty in gas channeling control,high process requirements,limited application scenarios,and coordination challenges in CO_(2)flooding and storage,and to support the large-scale application of CCUS,it is necessary to strengthen research on key technologies for establishing the third-generation CO_(2)flooding and storage technological system incorporating miscibility enhancement and transformation,comprehensive regulation for sweep enhancement,whole-process engineering techniques and equipment,long-term storage monitoring safety,and synergistic optimization of flooding and storage.
文摘The author affiliation and the funding information in the Acknowledgement section of the online version of the original article was revised.One affiliation(the 8th affiliation)of the first author is added.The Acknowledgement section of the original article has been revised to:Acknowledgments:This research was funded by the National University of Mongolia under grant agreement P2023(grant number P2023-4578)and supported by the Chey Institute for Advanced Studies“International Scholarship Exchange Fellowship for the academic year of 2024-2025”,Republic of Korea,and the National University of Mongolia.We would like to acknowledge the National University of Mongolia and Soumik Das from the Center for the Study of Regional Development,Jawaharlal Nehru University,New Delhi-110067,for his valuable assistance in preparing the geological maps.
基金supported by the Major Science and Technology Project(Nos.CNOOC-KJ 135 ZDXM 38 ZJ 01 ZJ,KJGG2021-0505) of CNOOC Co.,Ltd.of Chinathe National Natural Science Foundation of China(No.42002171)+2 种基金China Postdoctoral Science Foundation(Nos.2020TQ0299,2020M682520)Postdoctoral Innovation Science Foundation of Hubei Province of ChinaScientific Research Project of Zhanjiang Branch of CNOOC(No.ZYKY-2022-ZJ-02)。
文摘To investigate the relationship between grain sizes, seepage capacity, and oil-displacement efficiency in the Liushagang Formation of the Beibuwan Basin, this study identifies the multistage pore-throat structure as a crucial factor through a comparison of oil displacement in microscopic pore-throat experiments. The two-phase flow evaluation method based on the Li-Horne model is utilized to effectively characterize and quantify the seepage characteristics of different reservoirs, closely relating them to the distribution of microscopic pores and throats. It is observed that conglomerate sandstones at different stages exhibit significant heterogeneity and noticeable differences in seepage capacity, highlighting the crucial role played by certain large pore throats in determining seepage capacity and oil displacement efficiency. Furthermore, it was found that the displacement effects of conglomeratic sandstones with strong heterogeneity were inferior to those of conventional homogeneous sandstone, as evidenced by multiple displacement experiments conducted on core samples with varying granularities and flooding systems. Subsequently, core-based experiments on associated gas flooding after water flooding were conducted to address the challenge of achieving satisfactory results in a single displacement mode for reservoirs with significant heterogeneity. The results indicate that the oil recovery rates for associated gas flooding after water flooding increased by 7.3%-16.4% compared with water flooding alone at a gas-oil ratio of approximately 7000 m^(3)/m^(3). Therefore, considering the advantages of gas flooding in terms of seepage capacity, oil exchange ratio, and the potential for two-phase production, gas flooding is recommended as an energy supplement mode for homogeneous reservoirs in the presence of sufficient gas source and appropriate tectonic angle. On the other hand, associated gas flooding after water flooding is suggested to achieve a more favorable development effect compared to a single mode of energy supplementation for strongly heterogeneous sandstone reservoirs.
基金supported by the National Natural Science Foundation of China(Nos.42277034 and 42207249)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110904)+1 种基金the Guangdong Academy of Sciences(GDAS)Project of Science and Technology Development(No.2022GDASZH-2022010105)the Guangdong Foundation for Program of Science and Technology Research(No.2020B1212060048)。
文摘Zero-valent iron(ZVI)is a promising material for the remediation of Cd-contaminated paddy soils.However,the effects of ZVI added during flooding or drainage processes on cadmium(Cd)retention remain unclear.Herein,Cd-contaminated paddy soil was incubated for 40days of flooding and then for 15 days of drainage,and the underlying mechanisms of Cd immobilization coupled with Fe/S/N redox processes were investigated.The addition of ZVI to the flooding process was more conducive to Cd immobilization.Less potential available Cd was detected by adding ZVI before flooding,which may be due to the increase in paddy soil pH and newly formed secondary Fe minerals.Moreover,the reductive dissolution of Fe minerals promoted the release of soil colloids,thereby increasing significantly the surface sites and causing Cd immobilization.Additionally,the addition of ZVI before flooding played a vital role in Cd retention after soil drainage.In contrast,the addition of ZVI in the drainage phase was not conducive to Cd retention,which might be due to the rapid decrease in soil pH that inhibited Cd adsorption and further immobilization on soil surfaces.The findings of this study demonstrated that Cd availability in paddy soil was largely reduced by adding ZVI during the flooding period and provide a novel insight into the mechanisms of ZVI remediation in Cd-contaminated paddy soils.
基金the National Natural Science Foundation of China(Grants No.42041006,41790443 and 41927806).
文摘The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing to insufficient evidence,the quantitative correlation between flooding and climate change remains illdefined.We present a long time series of maximum flood discharge in the YRB dating back to 1843 compiled from historical documents and instrument measurements.Variations in yearly maximum flood discharge show distinct periods:a dramatic decreasing period from 1843 to 1950,and an oscillating gentle decreasing from 1950 to 2021,with the latter period also showing increasing more extreme floods.A Mann-Kendall test analysis suggests that the latter period can be further split into two distinct sub-periods:an oscillating gentle decreasing period from 1950 to 2000,and a clear recent increasing period from 2000 to 2021.We further predict that climate change will cause an ongoing remarkable increase in future flooding risk and an∼44.4 billion US dollars loss of floods in the YRB in 2100.
