Many labdane-related diterpenoids(LRDs) exhibit high values in drug development.Their diversity in structure and bioactivity,to a large extent,arise from oxidative modifications which are mainly catalyzed by cytochrom...Many labdane-related diterpenoids(LRDs) exhibit high values in drug development.Their diversity in structure and bioactivity,to a large extent,arise from oxidative modifications which are mainly catalyzed by cytochrome P450s(CYPs).The medicinal plant Euphorbia fischeriana Steud.is rich in LRDs with distinct scaffolds.Herein,we characterized three cytochrome P450s involved in LRD biosynthesis from this plant.Notably,CYP71D450 and CYP701A148 are two substrate-promiscuity CYPs.The former is the first example of CYPs which can oxidize C-3 of ent-atisane skeleton and ent-isopimara-7(8),15-diene,and the latter is the first example of CYPs which can oxidize C-19 of ent-abietane and ent-pimarane skeletons.This study expands the toolkit for bioproduction of diverse LRDs.展开更多
To address the challenges associated with existing separated zone oil production technologies,such as incompatibility with pump inspection operations,short effective working life,and poor communication reliability,an ...To address the challenges associated with existing separated zone oil production technologies,such as incompatibility with pump inspection operations,short effective working life,and poor communication reliability,an innovative electromagnetic coupling intelligent zonal oil production technology has been proposed.The core and accessory tools have been developed and applied in field tests.This technology employs a pipe string structure incorporation a release sub,which separates the production and allocation pipe strings.When the two strings are docked downhole,electromagnetic coupling enables close-range wireless transmission of electrical power and signals between the strings,powering multiple downhole intelligent production allocators(IPAs)and enabling two-way communication.Core tools adapted to the complex working conditions downhole were developed,including downhole electricity&signal transmission equipment based on electromagnetic coupling(EST),IPAs,and ground communication controllers(GCCs).Accessory tools,including large-diameter release sub anchor and cable-crossing packers,have also been technically finalized.Field tests conducted on ten wells in Daqing Oilfield demonstrated that the downhole docking of the two strings was convenient and reliable,and the EST worked stably.Real-time monitoring of flow rate,pressure and temperature in separate layers and regulation of zonal fluid production were also achieved.This technology has enhanced reservoir understanding and achieved practical production results of increased oil output with reduced water cut.展开更多
Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesi...Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesis and food processing.However,over 90 % of industrial H_(2)O_(2) is currently produced through the multi-step anthraquinone oxidation process,which suffers from a process with some drawbacks such as complex,high-energy consumption,and toxic byproducts emissions.Compared to the traditional anthraquinone method,artificial photosynthesis of H_(2)O_(2) using semiconductor photocatalysts has emerged as a sustainable alternative due to its use of water and O_(2) as the clean reactants and sole energy as the driving force.In recent years,metal-free photocatalysts mainly including covalent organic frameworks(COFs),covalent triazine frameworks(CTFs) and carbon nitrile(g-C_(3)N_(4)) have garnered significant interest due to their superior thermal and chemical stability,diverse synthesis methods,tunable functionality,light weight nature and non-toxicity.These materials also exhibit adjustable band structure and unique photoelectric properties.Sustainable efforts have been made to advance metal-free photocatalysts for artificial photosynthesis of H_(2)O_(2),however,a comprehensive summary of current research status on metalfree-based photocatalytic overall H_(2)O_(2) production remain scarce.This review outlines recent process in overall H_(2)O_(2) photosynthesis based on metal-free photocatalysts.First,we introduced the fundamental concepts of photocatalytic overall H_(2)O_(2) production.Then,we analyze representative studies on photocatalytic overall H_(2)O_(2) synthesis using metal-free materials.Finally,we discuss the challenges and future perspectives in this field to guide the design and synthesis of metal-free systems for H_(2)O_(2) generation.展开更多
Long-termpetroleum production forecasting is essential for the effective development andmanagement of oilfields.Due to its ability to extract complex patterns,deep learning has gained popularity for production forecas...Long-termpetroleum production forecasting is essential for the effective development andmanagement of oilfields.Due to its ability to extract complex patterns,deep learning has gained popularity for production forecasting.However,existing deep learning models frequently overlook the selective utilization of information from other production wells,resulting in suboptimal performance in long-term production forecasting across multiple wells.To achieve accurate long-term petroleum production forecast,we propose a spatial-geological perception graph convolutional neural network(SGP-GCN)that accounts for the temporal,spatial,and geological dependencies inherent in petroleum production.Utilizing the attention mechanism,the SGP-GCN effectively captures intricate correlations within production and geological data,forming the representations of each production well.Based on the spatial distances and geological feature correlations,we construct a spatial-geological matrix as the weight matrix to enable differential utilization of information from other wells.Additionally,a matrix sparsification algorithm based on production clustering(SPC)is also proposed to optimize the weight distribution within the spatial-geological matrix,thereby enhancing long-term forecasting performance.Empirical evaluations have shown that the SGP-GCN outperforms existing deep learning models,such as CNN-LSTM-SA,in long-term petroleum production forecasting.This demonstrates the potential of the SGP-GCN as a valuable tool for long-term petroleum production forecasting across multiple wells.展开更多
The clinical application of solid lipid particles(SLPs)is hampered due to the need for advanced nano/micro-suspension production technology.This research aims to establish a pilot-scale production line employing high-...The clinical application of solid lipid particles(SLPs)is hampered due to the need for advanced nano/micro-suspension production technology.This research aims to establish a pilot-scale production line employing high-speed shears as emulsification equipment.The primary purpose is to manufacture nano/micro-suspensions using solid lipid particles(SLPs).The study also exhaustively introduces and analyzes the regulatory schemes for process parameters and formulations at various stages of production.The process and formulation endured optimization through orthog-onal or single-factor tests at various production steps:laboratory research,small-scale trial production,and pilot production.Quality standards for the product were determined,and key parameters were obtained at each stage.The laboratory research demonstrated that the optimal SLPs comprised 15 mL 3%polyvinyl alcohol(PVA)per 1.0 g tilmicosin and 2.5 g carnauba wax(WAX).During small-scale production,modifications were made to the volume of the aqueous phase,emulsifier concentration,and emulsification strength,setting them to 16 mL,5%,and 2200 r/min,respectively.In the pilot production stage,the shear time was considered optimal at eight min.The impurity,content,polydispersion coefficient(PDI),and size of the pilot product were<3%,5%,0385 and 2.64μm,respectively.Among the several parameters studied,heating temperature,drug-lipid ratio,and emulsifier concentration were identified as the main factors affecting product quality,and they were regulated at 100℃,1:3,and 5%,respectively.A novel hot melt emulsification shear method aided the development of a new solid lipid-based suspension from its preliminary stages in the laboratory to pilot production.This innovation is expected to enhance solid lipid-based suspensions'industrial evolution extensively.展开更多
This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adap...This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adaptability of oilfields in China,the development of separate zone oil production technology is divided into four stages:flowing well zonal oil production,mechanical recovery and water blocking,hydraulically adjustable zonal oil production,and intelligent zonal production.The principles,construction processes,adaptability,advantages and disadvantages of the technology are introduced in detail.Based on the actual production situation of the oilfields in China at present,three development directions of the technology are proposed.First,the real-time monitoring and adjustment level of separated zone oil production needs to be improved by developing downhole sensor technology and two-way communication technology between ground and downhole and enhancing full life cycle service capability and adaptability to horizontal wells.Second,an integrated platform of zonal oil production and management should be built using a digital artificial lifting system.Third,integration of injection and production should be implemented through large-scale application of zonal oil production and zonal water injection to improve matching and adjustment level between the injection and production parameters,thus making the development adjustment from"lag control"to"real-time optimization"and improving the development effect.展开更多
Aligning leaf nitrogen(N) distribution to match the light gradient is crucial for maximizing canopy dry matter production(DMP) and improving N utilization efficiency. However, the relationship between the gradient of ...Aligning leaf nitrogen(N) distribution to match the light gradient is crucial for maximizing canopy dry matter production(DMP) and improving N utilization efficiency. However, the relationship between the gradient of root-derived cytokinins and N distribution in rice leaves and its impact on DMP and the underlying mechanisms remains poorly understood. A two-year field experiment was conducted using two japonica N-efficient varieties(NEVs) and two japonica N-inefficient varieties(NIVs) under four different N rates(0, 90, 180, and 360 kg N ha^(-1)). These selected varieties exhibited similar values in the coefficient of light extinction(K_(L)). Results showed that at lower N rates(0–180 kg N ha^(-1)), the NEVs exhibited greater dry matter weight at maturity, higher grain yield, and improved internal N use efficiency(IE_(N)) compared to the NIVs, despite possessing comparable total N uptake. Compared with the NIVs, the NEVs exhibited a more pronounced nitrogen distribution gradient in leaves, as indicated by the coefficient of nitrogen extinction(K_(N)) values during the middle and early grain-filling stages. This enhanced gradient led to improved coordination between light and nitrogen, resulting in greater photosynthetic production, particularly at lower N rates. Furthermore, the NEVs demonstrated a larger gradient of zeatin(Z)+zeatin riboside(ZR) in leaves(i.e., higher ratios of Z+ZR levels between upper and lower leaves), enhanced expression levels of genes related to N export in lower leaves and Z+ZR loading in the root, respectively, elevated enzymes activities related to N assimilation in upper leaves, in relative to the NIVs. Correlation and random forest analyses demonstrated a strong positive correlation between the Z+ZR gradient, K_(N), and DMP, and the gradient facilitated the export of N from lower leaves and its assimilation in upper leaves, contributing significantly to both K_(N) and DMP. This process was closely linked to root activity, including root oxidation activity, root Z+ZR content, and Z+ZR loading capacity, as confirmed by applying an inhibitor or a promoter of cytokinins biosynthesis to roots. Interestingly, at the N rate of 360 kg N ha^(-1), both NEVs and NIVs showed indistinguishable plant traits, achieving a super high-yielding level(over 10.5 t ha^(-1)) but with remarkably low IE_(N). The results suggest that increasing the Z+ZR gradient can improve K_(N) and DMP, where it needs to maintain higher root activity, thus leading to high yield and high IE_(N). Further research is needed to explore and develop cultivation practices with reduced N to unlock the super-high-yielding potential of the NEVs.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
The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,w...The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,we developed a novel hybrid seed production scheme using herbicide-resistance alleles(OsALS and CYP81A6).P/TGMS lines were bred for imazamox sensitivity and bentazon resistance,while male parents were engineered for the opposite traits.This system enables mechanical harvesting and ensures hybrid purity by eliminating self-pollinated contaminants through herbicide application.We identified suitable sterile lines and developed complementary male parents via breeding and CRISPR/Cas9 editing,validated through herbicide assays.This strategy enhances hybrid seed purity and mechanization efficiency in two-line hybrid rice production.展开更多
Objective To explore the risk management of the changes of sponsors and/or production sites during drug clinical trials based on the theories of quality management,risk management,and change management.Methods The met...Objective To explore the risk management of the changes of sponsors and/or production sites during drug clinical trials based on the theories of quality management,risk management,and change management.Methods The method of failure modes and effect analysis(FMEA)was used to identify risks through literature research,expert consultation,comparative research,and comprehensive analysis.Besides,risk priority number(RPN)was used to evaluate the risks.Results and Conclusion A FMEA of the changes of sponsors and/or production sites in clinical trials was constructed and RPN values of every failure mode and causes were obtained.Based on the RPN values,the core risk control points for different combination modes of sponsors and/or production sites after their changes were identified.It is recommended that China should strengthen the construction of the sponsor responsibility system.In addition,the changes of sponsors and/or production sites during the clinical trial period should be allowed in an orderly manner under the premise of ensuring the quality of clinical trials and subject protection.展开更多
Assessing the sensitivities of ecosystem functions to climatic factors is essential to understanding the response of ecosystems to environmental change.Temperate plantation forests contribute to global greening and cl...Assessing the sensitivities of ecosystem functions to climatic factors is essential to understanding the response of ecosystems to environmental change.Temperate plantation forests contribute to global greening and climate change mitigation,yet little is known as to the sensitivity of gross primary production(GPP)and evapotranspiration(ET)of these forests to heat and drought stress.Based on near-continuous,eddy-covariance and hydrometeorological data from a young temperate plantation forest in Beijing,China(2012-2019),we used a slidingwindow-fitting technique to assess the seasonal and interannual variation in ecosystem sensitivity(i.e.,calculated slopes,S_(GPP-Ta),S_(ET-Ta),S_(GPP-EF),and S_(ET-EF))in GPP and ET to anomalies in air temperature(T_(a))and evaporative fraction(EF).The EF was used here as an indicator of drought.Seasonally,daily SGPP-Ta,SET-Ta,and SGPP-EF were greatest in summer,reaching maxima of 1.120.56 g C··m^(-2)·d^(-1)·℃^(-1),1.360.56 g H_(2)O·m^(-2)·d^(-1)·℃^(-1),and 0.370.35 g C·m^(-2)·d^(-1),respectively.Evapotranspiration was constrained by drought,especially during the spring-to-summer period,SET-EF reaching0.510.34 g H_(2)O·m^(-2)·d^(-1).Variables EF,T_(a),soil water content(SWC),vapor pressure deficit(VPD),and precipitation(PPT)were the main controls of sensitivity,with SGPP-Ta and SET-Ta increasing with Ta,VPD,and PPT(<50 mm·d^(-1))during both spring and autumn.Increased drought stress during summer caused the positive response in GPP and ET to decrease with atmospheric warming.Variable SET-EF intensified(i.e.,became more negative)with decreasing EF and increasing Ta.Interannually,annual S_(GPP-Ta)and S_(ET-Ta)were positive,S_(GPP-EF)near-neutral,and S_(ET-EF)negative.Interannual variability in S_(GPP-Ta),S_(ET-Ta),S_(ET-EF),and S_(GPP-EF)was largely due to variations in bulk surface conductance.Our study suggests that the dynamics associated with the sensitivity of ecosystems to changes in climatic factors need to be considered in the management of plantation forests under future global climate change.展开更多
On-time mapping dynamics of crop area,yield,and production is important for global food security.Such information,however,is often not available.Here,we used satellite information,a spectral-phenology integration appr...On-time mapping dynamics of crop area,yield,and production is important for global food security.Such information,however,is often not available.Here,we used satellite information,a spectral-phenology integration approach for mapping crop area,and a machine learning model for predicting yield in the war-stricken Ukraine.We found that in Ukraine crop area and production declined in 2022 relative to 2017–2021 and 2021 for wintertriticeae crops,which was invaded before the cropping season in February of that year.At the same time,crop area and production for rapeseed increased in Ukraine,with yields consistently lower by 6.5%relative to 2021.The low precipitation and the Russian-Ukrainian conflict-related factors contributed to such yield variations by-1.3%and-0.9%for winter-triticeae crops and-4.2%and-0.5%for rapeseed in 2022.We demonstrate a robust framework for monitoring country-wide crop production dynamics in near real-time,serving as an early-foodsecurity-warning system.展开更多
Carbon dioxide enhanced oil recovery(CO_(2)-EOR)technology is used for oil production and CO_(2) storage in reservoirs.Methods are being constantly developed to optimize oil recovery and CO_(2) storage during the CO_(...Carbon dioxide enhanced oil recovery(CO_(2)-EOR)technology is used for oil production and CO_(2) storage in reservoirs.Methods are being constantly developed to optimize oil recovery and CO_(2) storage during the CO_(2) displacement process,especially for low-permeability reservoirs under varying geological conditions.In this study,long-core experiments and trans-scale numerical simulations are employed to examine the characteristics of oil production and CO_(2) storage.Optimal production parameters for the target reservoir are also proposed.The results indicate that maintaining the pressure at 1.04 to 1.10 times the minimum miscible pressure(MMP)and increasing the injection rate can enhance oil production in the early stage of reservoir development.In contrast,reducing the injection rate at the later stages prevents CO_(2) channeling,thus improving oil recovery and CO_(2) storage efficiency.A solution-doubling factor is introduced to modify the calculation method for CO_(2) storage,increasing its accuracy to approximately 90%.Before CO_(2) breakthrough,prioritizing oil production is recommended to maximize the economic benefits of this process.In the middle stage of CO_(2) displacement,decreasing the injection rate optimizes the coordination between oil displacement and CO_(2) storage.Further,in the late stage,reduced pressure and injection rates are required as the focus shifts to CO_(2) storage.展开更多
The dynamic relationship between field management and reservoir characterization has often been a puzzle,especially in complex deepwater channel systems.Reservoir management and infill drilling success cases were ofte...The dynamic relationship between field management and reservoir characterization has often been a puzzle,especially in complex deepwater channel systems.Reservoir management and infill drilling success cases were often due to improved understanding of deepwater depositional systems and geological controls on channel architecture and the general distribution of individual rock facies.For confined to weakly-confined slope channel complexes,some controls on the degree of channel avulsion and aggradation are the interplay between flow hydraulics,sediment calibre,depositional gradient,and the interaction of the flow with underlying substrate.This work aims at documenting the stratigraphic characterization of a Miocene deepwater channel system in a brownfield with focus on the historical evolution of the framework interpretation as well as applications of the recent updates in field management.The initial stratigraphic model(2005)was done using the layer cake concept with minimal incision,continuous shales and limited vertical connectivity based on observations from available seismic data(pre-baseline survey acquisition)and limited well control.This was modified in 2009 following acquisition of a 4D Monitor 1 seismic volume and 3 years production data from 20 wells to a more erosive model with compensationally stacked channel complexes of similar width.With new 4D Monitor 2 acquired in 2014,broadband processed seismic data in 2020,a total of 36 wells and 11 years of production,an updated framework has recently been built.In the new framework,two key fairways namely the Upper and the Lower Fairway were delineated,each comprising of 8 and 6 channel complexes,respectively.A conceptual basin-fill sequence was utilized,as well as a genetic classification of the channel complexes into erosional-confined systems,meandering systems,and levee-confined channel systems.The cut-and-fill behaviors of the individual complexes have been tied to changes in depositional gradient,sediment sand vs mud ratio,interaction of the flow with the substrate,and this has impacted the degree of channel amalgamation,avulsion and the degree of preservation of both internal and external levees.At flow unit scale,potential inter,and intra-reservoir connection pathways and compartments defined through integrated use of excess pressures,geobody attributes,well production and 4D data,have been very helpful in defining reservoir connection windows,injector-producer connectivity,and channel compartments.The implication is that this exercise or study has provided renewed insights into infill drill-well opportunities,well production performance as well as overall field management strategy.展开更多
This study introduces a comprehensive and automated framework that leverages data-driven method-ologies to address various challenges in shale gas development and production.Specifically,it harnesses the power of Auto...This study introduces a comprehensive and automated framework that leverages data-driven method-ologies to address various challenges in shale gas development and production.Specifically,it harnesses the power of Automated Machine Learning(AutoML)to construct an ensemble model to predict the estimated ultimate recovery(EUR)of shale gas wells.To demystify the“black-box”nature of the ensemble model,KernelSHAP,a kernel-based approach to compute Shapley values,is utilized for elucidating the influential factors that affect shale gas production at both global and local scales.Furthermore,a bi-objective optimization algorithm named NSGA-Ⅱ is seamlessly incorporated to opti-mize hydraulic fracturing designs for production boost and cost control.This innovative framework addresses critical limitations often encountered in applying machine learning(ML)to shale gas pro-duction:the challenge of achieving sufficient model accuracy with limited samples,the multidisciplinary expertise required for developing robust ML models,and the need for interpretability in“black-box”models.Validation with field data from the Fuling shale gas field in the Sichuan Basin substantiates the framework's efficacy in enhancing the precision and applicability of data-driven techniques.The test accuracy of the ensemble ML model reached 83%compared to a maximum of 72%of single ML models.The contribution of each geological and engineering factor to the overall production was quantitatively evaluated.Fracturing design optimization raised EUR by 7%-34%under different production and cost tradeoff scenarios.The results empower domain experts to conduct more precise and objective data-driven analyses and optimizations for shale gas production with minimal expertise in data science.展开更多
The fracture volume is gradually changed with the depletion of fracture pressure during the production process.However,there are few flowback models available so far that can estimate the fracture volume loss using pr...The fracture volume is gradually changed with the depletion of fracture pressure during the production process.However,there are few flowback models available so far that can estimate the fracture volume loss using pressure transient and rate transient data.The initial flowback involves producing back the fracturing fuid after hydraulic fracturing,while the second flowback involves producing back the preloading fluid injected into the parent wells before fracturing of child wells.The main objective of this research is to compare the initial and second flowback data to capture the changes in fracture volume after production and preload processes.Such a comparison is useful for evaluating well performance and optimizing frac-turing operations.We construct rate-normalized pressure(RNP)versus material balance time(MBT)diagnostic plots using both initial and second flowback data(FB;and FBs,respectively)of six multi-fractured horizontal wells completed in Niobrara and Codell formations in DJ Basin.In general,the slope of RNP plot during the FB,period is higher than that during the FB;period,indicating a potential loss of fracture volume from the FB;to the FB,period.We estimate the changes in effective fracture volume(Ver)by analyzing the changes in the RNP slope and total compressibility between these two flowback periods.Ver during FB,is in general 3%-45%lower than that during FB:.We also compare the drive mechanisms for the two flowback periods by calculating the compaction-drive index(CDI),hydrocarbon-drive index(HDI),and water-drive index(WDI).The dominant drive mechanism during both flowback periods is CDI,but its contribution is reduced by 16%in the FB,period.This drop is generally compensated by a relatively higher HDI during this period.The loss of effective fracture volume might be attributed to the pressure depletion in fractures,which occurs during the production period and can extend 800 days.展开更多
This study examines the role of maize in food security and economic stability,focusing on its response to climate change and strategies to enhance resilience.Using a qualitative descriptive research methodology,the st...This study examines the role of maize in food security and economic stability,focusing on its response to climate change and strategies to enhance resilience.Using a qualitative descriptive research methodology,the study analyzes the impact of climate change on global maize production and proposes innovative strategies for sustainability and food security.The agricultural environment is vulnerable to heavy metal toxicity,which is linked to the relationship between soil health and climate change.From 1850 to 2020,the Earth’s temperature increased by 1.1℃,with projections indicating continued warming.This trend has significant economic implications,particularly in developing countries where agriculture employs 69%of the population.Heat waves and droughts represent abiotic stresses faced by maize.Research suggests that high greenhouse gas emissions could lead to a 24%reduction in maize yield by 2030.The study highlights the need to focus on breeding and phenotyping technologies to develop heat-and drought-tolerant maize varieties that use water efficiently.Additionally,strategies such as genomic editing,transcriptome analysis,and maize quality mapping are crucial to addressing these challenges.Developing insect-resistant maize is another objective.This study emphasizes the necessity of ongoing research to improve agricultural productivity and ensure food security,especially in light of global population growth.It also advocates for new regulations to reduce greenhouse gas emissions,which contribute to global warming.展开更多
This study explores the impact of salinity on fluid replacement during imbibition-driven oil recovery through a series of core self-imbibition experiments.By integrating key parameters such as interfacial tension,cont...This study explores the impact of salinity on fluid replacement during imbibition-driven oil recovery through a series of core self-imbibition experiments.By integrating key parameters such as interfacial tension,contact angle,and oil displacement efficiency,we systematically examine how variations in salinity level,ion type,and ion concentration affect the imbibition process.The results demonstrate that the salinity of the injected fluid exerts a strong influence on the rate and extent of oil recovery.Compared with high-salinity conditions,low-salinity injection,particularly below 5000 mg.L-1,induces pronounced fluctuations in the replacement rate,achieving the highest recovery at approximately 1000 mg·L-1.The interplay between interfacial tension and displacement efficiency is jointly governed by both ion type and concentration.Moreover,changes in ionic composition can alter rock wettability from oil-wet toward water-wet states,thereby enhancing imbibition efficiency.Among the tested ions,Mg2+and SO4²at low concentrations were found to be especially effective in promoting oil displacement.展开更多
Natural gas hydrate widely exists in the South China Sea as clean energy.A three-phase transition layer widely exists in low permeability Class I hydrates in the Shenhu offshore area.Therefore,taking into account the ...Natural gas hydrate widely exists in the South China Sea as clean energy.A three-phase transition layer widely exists in low permeability Class I hydrates in the Shenhu offshore area.Therefore,taking into account the low-permeability characteristics with an average permeability of 5.5 mD and moderate heterogeneity,a 3-D geological model of heterogeneous Class I hydrate reservoirs with three-phase transition layers is established by Kriging interpolation and stochastic modeling method,and a numerical simulation model is used to describe the depressurization production performance of the reservoir.With the development of depressurization,a specific range of complete decomposition zones appear both in the hydrate and transition layers.The entire decomposition zone of the whole reservoir tends to outward and upward diffusion.There is apparent methane escape in the three-phase transition layer.Due to the improvement of local permeability caused by the phase transition of hydrate dissociation,some methane accumulation occurs at the bottom of the hydrate layer,forming a local methane enrichment zone.The methane migration trends in reservoirs are mainly characterized by movement toward production wells and hydrate layers under the influence of gravity.However,due to the permeability limitation of hydrate reservoirs,many fluids have not been effectively produced and remain in the reservoir.Therefore,to improve the effective pressure drop of the reservoir,the perforation method and pressure reduction method were optimized by analyzing the influencing factors based on the gas production rate.The comparative study demonstrates that perforating through the free gas layer combined with one-time depressurization can enhance the effective depressurization and improve production performance.The gas production rate from perforating through the free gas layer can be twice as high as that from perforating through the transition layer.This study can provide theoretical support for the utilization of marine energy.展开更多
Global warming and climate change have made food production through conventional agriculture inefficient, and their effects on livestock and crop cultivation are leading to disruptions in the food supply. The troubles...Global warming and climate change have made food production through conventional agriculture inefficient, and their effects on livestock and crop cultivation are leading to disruptions in the food supply. The troubles are severe in regions suffering from improper land management and unsustainable practices. The Bio-CircularGreen(BCG) economic model, designed to reduce and recycle resources by using environmentally friendly procedures, has been developed. The Azolla plant represents an interesting model for BCG and for enhancing community networks in Southeast Asia(SEA) because it provides multipurpose materials. Azolla can be used for various applications in agriculture such as biofertilizer and animal feed. However, our understanding and utilization of Azolla are limited. Moreover, collaboration among farmers is insufficient to maximize the benefits of Azolla. In this study, we provide a comprehensive review of the role of Azolla in agriculture. We review the main properties of Azolla as biofertilizers, especially regarding rice production and the interaction with cyanobacteria. For livestock, we discuss procedures to use Azolla in animal feed and evaluate the ingredients of the meal. In addition, we discuss product qualities from livestock treated with Azolla in the diet. This review also describes Azolla-based farming, which is designed for efficient land use and promotes nutrient cycling.Hence, we show that the Azolla plant is one of the key factors for farm-based agroecosystem services which can drive sustainable bioresource management in SEA. Moreover, we also propose the potential development of Azolla to improve its properties as a biofertilizer, a functional feed for animals and humans, and a feedstock for bio-oil production.展开更多
基金supported by grants from the National Natural Science Foundation of China [Nos.82474024,82293682 (82293680),82073953]the Nonprofit Central Research Institute Fund of Chinese Academy of Medical Sciences (No.2021-RC350-009)+1 种基金the CAMS Innovation Fund for Medical Sciences (No.2023-I2M-2-006)the Special Fund for the Construction of Qinghai Innovation Platform (No.2024-ZJ-T02)。
文摘Many labdane-related diterpenoids(LRDs) exhibit high values in drug development.Their diversity in structure and bioactivity,to a large extent,arise from oxidative modifications which are mainly catalyzed by cytochrome P450s(CYPs).The medicinal plant Euphorbia fischeriana Steud.is rich in LRDs with distinct scaffolds.Herein,we characterized three cytochrome P450s involved in LRD biosynthesis from this plant.Notably,CYP71D450 and CYP701A148 are two substrate-promiscuity CYPs.The former is the first example of CYPs which can oxidize C-3 of ent-atisane skeleton and ent-isopimara-7(8),15-diene,and the latter is the first example of CYPs which can oxidize C-19 of ent-abietane and ent-pimarane skeletons.This study expands the toolkit for bioproduction of diverse LRDs.
基金Supported by the National Natural Science Foundation of China(52374067)PetroChina Scientific Research and Technology Development Project(2021ZG12)PetroChina Technology Project(2023ZZ09).
文摘To address the challenges associated with existing separated zone oil production technologies,such as incompatibility with pump inspection operations,short effective working life,and poor communication reliability,an innovative electromagnetic coupling intelligent zonal oil production technology has been proposed.The core and accessory tools have been developed and applied in field tests.This technology employs a pipe string structure incorporation a release sub,which separates the production and allocation pipe strings.When the two strings are docked downhole,electromagnetic coupling enables close-range wireless transmission of electrical power and signals between the strings,powering multiple downhole intelligent production allocators(IPAs)and enabling two-way communication.Core tools adapted to the complex working conditions downhole were developed,including downhole electricity&signal transmission equipment based on electromagnetic coupling(EST),IPAs,and ground communication controllers(GCCs).Accessory tools,including large-diameter release sub anchor and cable-crossing packers,have also been technically finalized.Field tests conducted on ten wells in Daqing Oilfield demonstrated that the downhole docking of the two strings was convenient and reliable,and the EST worked stably.Real-time monitoring of flow rate,pressure and temperature in separate layers and regulation of zonal fluid production were also achieved.This technology has enhanced reservoir understanding and achieved practical production results of increased oil output with reduced water cut.
基金supported by the National Natural Science Foundation of China (No.22409038,52473221)Zhejiang Province Postdoctoral Science Foundation (No.ZJ2024021)+2 种基金Hubei Provincial Natural Science Foundation of China (Nos.2024DJC032,2025AFB889)Key Project of Science and Technology Research of Hubei Provincial Department of Education (Nos.D20232701,D20232702)the research grant funded by the Research,Development,and Innovation Authority (RDIA)-Kingdom of Saudi Arabia (No.12615-iu-2023-IU-R-2-1-EI-)。
文摘Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesis and food processing.However,over 90 % of industrial H_(2)O_(2) is currently produced through the multi-step anthraquinone oxidation process,which suffers from a process with some drawbacks such as complex,high-energy consumption,and toxic byproducts emissions.Compared to the traditional anthraquinone method,artificial photosynthesis of H_(2)O_(2) using semiconductor photocatalysts has emerged as a sustainable alternative due to its use of water and O_(2) as the clean reactants and sole energy as the driving force.In recent years,metal-free photocatalysts mainly including covalent organic frameworks(COFs),covalent triazine frameworks(CTFs) and carbon nitrile(g-C_(3)N_(4)) have garnered significant interest due to their superior thermal and chemical stability,diverse synthesis methods,tunable functionality,light weight nature and non-toxicity.These materials also exhibit adjustable band structure and unique photoelectric properties.Sustainable efforts have been made to advance metal-free photocatalysts for artificial photosynthesis of H_(2)O_(2),however,a comprehensive summary of current research status on metalfree-based photocatalytic overall H_(2)O_(2) production remain scarce.This review outlines recent process in overall H_(2)O_(2) photosynthesis based on metal-free photocatalysts.First,we introduced the fundamental concepts of photocatalytic overall H_(2)O_(2) production.Then,we analyze representative studies on photocatalytic overall H_(2)O_(2) synthesis using metal-free materials.Finally,we discuss the challenges and future perspectives in this field to guide the design and synthesis of metal-free systems for H_(2)O_(2) generation.
基金funded by National Natural Science Foundation of China,grant number 62071491.
文摘Long-termpetroleum production forecasting is essential for the effective development andmanagement of oilfields.Due to its ability to extract complex patterns,deep learning has gained popularity for production forecasting.However,existing deep learning models frequently overlook the selective utilization of information from other production wells,resulting in suboptimal performance in long-term production forecasting across multiple wells.To achieve accurate long-term petroleum production forecast,we propose a spatial-geological perception graph convolutional neural network(SGP-GCN)that accounts for the temporal,spatial,and geological dependencies inherent in petroleum production.Utilizing the attention mechanism,the SGP-GCN effectively captures intricate correlations within production and geological data,forming the representations of each production well.Based on the spatial distances and geological feature correlations,we construct a spatial-geological matrix as the weight matrix to enable differential utilization of information from other wells.Additionally,a matrix sparsification algorithm based on production clustering(SPC)is also proposed to optimize the weight distribution within the spatial-geological matrix,thereby enhancing long-term forecasting performance.Empirical evaluations have shown that the SGP-GCN outperforms existing deep learning models,such as CNN-LSTM-SA,in long-term petroleum production forecasting.This demonstrates the potential of the SGP-GCN as a valuable tool for long-term petroleum production forecasting across multiple wells.
基金supported by the Fundamental Research Funds for the Central Universities(2662020DKPY008)the National Natural Science Foundation of China(grant No.31772797)。
文摘The clinical application of solid lipid particles(SLPs)is hampered due to the need for advanced nano/micro-suspension production technology.This research aims to establish a pilot-scale production line employing high-speed shears as emulsification equipment.The primary purpose is to manufacture nano/micro-suspensions using solid lipid particles(SLPs).The study also exhaustively introduces and analyzes the regulatory schemes for process parameters and formulations at various stages of production.The process and formulation endured optimization through orthog-onal or single-factor tests at various production steps:laboratory research,small-scale trial production,and pilot production.Quality standards for the product were determined,and key parameters were obtained at each stage.The laboratory research demonstrated that the optimal SLPs comprised 15 mL 3%polyvinyl alcohol(PVA)per 1.0 g tilmicosin and 2.5 g carnauba wax(WAX).During small-scale production,modifications were made to the volume of the aqueous phase,emulsifier concentration,and emulsification strength,setting them to 16 mL,5%,and 2200 r/min,respectively.In the pilot production stage,the shear time was considered optimal at eight min.The impurity,content,polydispersion coefficient(PDI),and size of the pilot product were<3%,5%,0385 and 2.64μm,respectively.Among the several parameters studied,heating temperature,drug-lipid ratio,and emulsifier concentration were identified as the main factors affecting product quality,and they were regulated at 100℃,1:3,and 5%,respectively.A novel hot melt emulsification shear method aided the development of a new solid lipid-based suspension from its preliminary stages in the laboratory to pilot production.This innovation is expected to enhance solid lipid-based suspensions'industrial evolution extensively.
基金Supported by the National Key Research and Development Program of China(2018YFE0196000)National Science and Technology Major Project of China(2016ZX05010-006)CNPC Scientific Research and Technical Development Project(2019B-4113)
文摘This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adaptability of oilfields in China,the development of separate zone oil production technology is divided into four stages:flowing well zonal oil production,mechanical recovery and water blocking,hydraulically adjustable zonal oil production,and intelligent zonal production.The principles,construction processes,adaptability,advantages and disadvantages of the technology are introduced in detail.Based on the actual production situation of the oilfields in China at present,three development directions of the technology are proposed.First,the real-time monitoring and adjustment level of separated zone oil production needs to be improved by developing downhole sensor technology and two-way communication technology between ground and downhole and enhancing full life cycle service capability and adaptability to horizontal wells.Second,an integrated platform of zonal oil production and management should be built using a digital artificial lifting system.Third,integration of injection and production should be implemented through large-scale application of zonal oil production and zonal water injection to improve matching and adjustment level between the injection and production parameters,thus making the development adjustment from"lag control"to"real-time optimization"and improving the development effect.
基金supported by the National Natural Science Foundation of China (32301930, 32071943, 32272198, and 32372214)the Major Program of the Ministry of Agriculture and Rural Affairs of China (FSNK202218080316)+3 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD-2020-01)the Jiangsu Funding Program for Excellent Postdoctoral Talent, China (2022ZB618)the Government Funding to the Chinese University of Hong Kong State Key Laboratory of Agrobiotechnology via Innovation and Technology Commission, China (2022/23–2023/24)the National Key Research and Development Program of China (2022YFD2300304)。
文摘Aligning leaf nitrogen(N) distribution to match the light gradient is crucial for maximizing canopy dry matter production(DMP) and improving N utilization efficiency. However, the relationship between the gradient of root-derived cytokinins and N distribution in rice leaves and its impact on DMP and the underlying mechanisms remains poorly understood. A two-year field experiment was conducted using two japonica N-efficient varieties(NEVs) and two japonica N-inefficient varieties(NIVs) under four different N rates(0, 90, 180, and 360 kg N ha^(-1)). These selected varieties exhibited similar values in the coefficient of light extinction(K_(L)). Results showed that at lower N rates(0–180 kg N ha^(-1)), the NEVs exhibited greater dry matter weight at maturity, higher grain yield, and improved internal N use efficiency(IE_(N)) compared to the NIVs, despite possessing comparable total N uptake. Compared with the NIVs, the NEVs exhibited a more pronounced nitrogen distribution gradient in leaves, as indicated by the coefficient of nitrogen extinction(K_(N)) values during the middle and early grain-filling stages. This enhanced gradient led to improved coordination between light and nitrogen, resulting in greater photosynthetic production, particularly at lower N rates. Furthermore, the NEVs demonstrated a larger gradient of zeatin(Z)+zeatin riboside(ZR) in leaves(i.e., higher ratios of Z+ZR levels between upper and lower leaves), enhanced expression levels of genes related to N export in lower leaves and Z+ZR loading in the root, respectively, elevated enzymes activities related to N assimilation in upper leaves, in relative to the NIVs. Correlation and random forest analyses demonstrated a strong positive correlation between the Z+ZR gradient, K_(N), and DMP, and the gradient facilitated the export of N from lower leaves and its assimilation in upper leaves, contributing significantly to both K_(N) and DMP. This process was closely linked to root activity, including root oxidation activity, root Z+ZR content, and Z+ZR loading capacity, as confirmed by applying an inhibitor or a promoter of cytokinins biosynthesis to roots. Interestingly, at the N rate of 360 kg N ha^(-1), both NEVs and NIVs showed indistinguishable plant traits, achieving a super high-yielding level(over 10.5 t ha^(-1)) but with remarkably low IE_(N). The results suggest that increasing the Z+ZR gradient can improve K_(N) and DMP, where it needs to maintain higher root activity, thus leading to high yield and high IE_(N). Further research is needed to explore and develop cultivation practices with reduced N to unlock the super-high-yielding potential of the NEVs.
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 Zhongshan Biological Breeding Laboratory,China(Grant No.ZSBBL-KY2023-07)the Jiangsu Agricultural Science and Technology Innovation Fund,China(Grant No.CX(22)3138)+1 种基金the National Natural Science Foundation of China(Grant Nos.32101736,32002124)the Jiangsu Provincial Key Research and Development Program,China(Grant No.BE2021360-2).
文摘The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,we developed a novel hybrid seed production scheme using herbicide-resistance alleles(OsALS and CYP81A6).P/TGMS lines were bred for imazamox sensitivity and bentazon resistance,while male parents were engineered for the opposite traits.This system enables mechanical harvesting and ensures hybrid purity by eliminating self-pollinated contaminants through herbicide application.We identified suitable sterile lines and developed complementary male parents via breeding and CRISPR/Cas9 editing,validated through herbicide assays.This strategy enhances hybrid seed purity and mechanization efficiency in two-line hybrid rice production.
文摘Objective To explore the risk management of the changes of sponsors and/or production sites during drug clinical trials based on the theories of quality management,risk management,and change management.Methods The method of failure modes and effect analysis(FMEA)was used to identify risks through literature research,expert consultation,comparative research,and comprehensive analysis.Besides,risk priority number(RPN)was used to evaluate the risks.Results and Conclusion A FMEA of the changes of sponsors and/or production sites in clinical trials was constructed and RPN values of every failure mode and causes were obtained.Based on the RPN values,the core risk control points for different combination modes of sponsors and/or production sites after their changes were identified.It is recommended that China should strengthen the construction of the sponsor responsibility system.In addition,the changes of sponsors and/or production sites during the clinical trial period should be allowed in an orderly manner under the premise of ensuring the quality of clinical trials and subject protection.
基金supported by the National Key Research and Development Program of China(No.2020YFA0608100)the National Natural Science Foundation of China(NSFC,No.32071842 and 32101588)。
文摘Assessing the sensitivities of ecosystem functions to climatic factors is essential to understanding the response of ecosystems to environmental change.Temperate plantation forests contribute to global greening and climate change mitigation,yet little is known as to the sensitivity of gross primary production(GPP)and evapotranspiration(ET)of these forests to heat and drought stress.Based on near-continuous,eddy-covariance and hydrometeorological data from a young temperate plantation forest in Beijing,China(2012-2019),we used a slidingwindow-fitting technique to assess the seasonal and interannual variation in ecosystem sensitivity(i.e.,calculated slopes,S_(GPP-Ta),S_(ET-Ta),S_(GPP-EF),and S_(ET-EF))in GPP and ET to anomalies in air temperature(T_(a))and evaporative fraction(EF).The EF was used here as an indicator of drought.Seasonally,daily SGPP-Ta,SET-Ta,and SGPP-EF were greatest in summer,reaching maxima of 1.120.56 g C··m^(-2)·d^(-1)·℃^(-1),1.360.56 g H_(2)O·m^(-2)·d^(-1)·℃^(-1),and 0.370.35 g C·m^(-2)·d^(-1),respectively.Evapotranspiration was constrained by drought,especially during the spring-to-summer period,SET-EF reaching0.510.34 g H_(2)O·m^(-2)·d^(-1).Variables EF,T_(a),soil water content(SWC),vapor pressure deficit(VPD),and precipitation(PPT)were the main controls of sensitivity,with SGPP-Ta and SET-Ta increasing with Ta,VPD,and PPT(<50 mm·d^(-1))during both spring and autumn.Increased drought stress during summer caused the positive response in GPP and ET to decrease with atmospheric warming.Variable SET-EF intensified(i.e.,became more negative)with decreasing EF and increasing Ta.Interannually,annual S_(GPP-Ta)and S_(ET-Ta)were positive,S_(GPP-EF)near-neutral,and S_(ET-EF)negative.Interannual variability in S_(GPP-Ta),S_(ET-Ta),S_(ET-EF),and S_(GPP-EF)was largely due to variations in bulk surface conductance.Our study suggests that the dynamics associated with the sensitivity of ecosystems to changes in climatic factors need to be considered in the management of plantation forests under future global climate change.
基金supported by the National Natural Science Foundation of China(Grant No.42061144003).
文摘On-time mapping dynamics of crop area,yield,and production is important for global food security.Such information,however,is often not available.Here,we used satellite information,a spectral-phenology integration approach for mapping crop area,and a machine learning model for predicting yield in the war-stricken Ukraine.We found that in Ukraine crop area and production declined in 2022 relative to 2017–2021 and 2021 for wintertriticeae crops,which was invaded before the cropping season in February of that year.At the same time,crop area and production for rapeseed increased in Ukraine,with yields consistently lower by 6.5%relative to 2021.The low precipitation and the Russian-Ukrainian conflict-related factors contributed to such yield variations by-1.3%and-0.9%for winter-triticeae crops and-4.2%and-0.5%for rapeseed in 2022.We demonstrate a robust framework for monitoring country-wide crop production dynamics in near real-time,serving as an early-foodsecurity-warning system.
基金funded by the National Science and Technology Major Project for the Exploration and Development of New Types of Oil and Gas(No.2024ZD14066)the National Natural Science Foundation of China(No.52274053)+1 种基金the Natural Science Foundation of Beijing Municipality(No.3173044)the Xinjiang Conglomerate Reservoir Laboratory Development Foundation Project(No.2020D04045)。
文摘Carbon dioxide enhanced oil recovery(CO_(2)-EOR)technology is used for oil production and CO_(2) storage in reservoirs.Methods are being constantly developed to optimize oil recovery and CO_(2) storage during the CO_(2) displacement process,especially for low-permeability reservoirs under varying geological conditions.In this study,long-core experiments and trans-scale numerical simulations are employed to examine the characteristics of oil production and CO_(2) storage.Optimal production parameters for the target reservoir are also proposed.The results indicate that maintaining the pressure at 1.04 to 1.10 times the minimum miscible pressure(MMP)and increasing the injection rate can enhance oil production in the early stage of reservoir development.In contrast,reducing the injection rate at the later stages prevents CO_(2) channeling,thus improving oil recovery and CO_(2) storage efficiency.A solution-doubling factor is introduced to modify the calculation method for CO_(2) storage,increasing its accuracy to approximately 90%.Before CO_(2) breakthrough,prioritizing oil production is recommended to maximize the economic benefits of this process.In the middle stage of CO_(2) displacement,decreasing the injection rate optimizes the coordination between oil displacement and CO_(2) storage.Further,in the late stage,reduced pressure and injection rates are required as the focus shifts to CO_(2) storage.
文摘The dynamic relationship between field management and reservoir characterization has often been a puzzle,especially in complex deepwater channel systems.Reservoir management and infill drilling success cases were often due to improved understanding of deepwater depositional systems and geological controls on channel architecture and the general distribution of individual rock facies.For confined to weakly-confined slope channel complexes,some controls on the degree of channel avulsion and aggradation are the interplay between flow hydraulics,sediment calibre,depositional gradient,and the interaction of the flow with underlying substrate.This work aims at documenting the stratigraphic characterization of a Miocene deepwater channel system in a brownfield with focus on the historical evolution of the framework interpretation as well as applications of the recent updates in field management.The initial stratigraphic model(2005)was done using the layer cake concept with minimal incision,continuous shales and limited vertical connectivity based on observations from available seismic data(pre-baseline survey acquisition)and limited well control.This was modified in 2009 following acquisition of a 4D Monitor 1 seismic volume and 3 years production data from 20 wells to a more erosive model with compensationally stacked channel complexes of similar width.With new 4D Monitor 2 acquired in 2014,broadband processed seismic data in 2020,a total of 36 wells and 11 years of production,an updated framework has recently been built.In the new framework,two key fairways namely the Upper and the Lower Fairway were delineated,each comprising of 8 and 6 channel complexes,respectively.A conceptual basin-fill sequence was utilized,as well as a genetic classification of the channel complexes into erosional-confined systems,meandering systems,and levee-confined channel systems.The cut-and-fill behaviors of the individual complexes have been tied to changes in depositional gradient,sediment sand vs mud ratio,interaction of the flow with the substrate,and this has impacted the degree of channel amalgamation,avulsion and the degree of preservation of both internal and external levees.At flow unit scale,potential inter,and intra-reservoir connection pathways and compartments defined through integrated use of excess pressures,geobody attributes,well production and 4D data,have been very helpful in defining reservoir connection windows,injector-producer connectivity,and channel compartments.The implication is that this exercise or study has provided renewed insights into infill drill-well opportunities,well production performance as well as overall field management strategy.
基金funded by the National Natural Science Foundation of China(42050104).
文摘This study introduces a comprehensive and automated framework that leverages data-driven method-ologies to address various challenges in shale gas development and production.Specifically,it harnesses the power of Automated Machine Learning(AutoML)to construct an ensemble model to predict the estimated ultimate recovery(EUR)of shale gas wells.To demystify the“black-box”nature of the ensemble model,KernelSHAP,a kernel-based approach to compute Shapley values,is utilized for elucidating the influential factors that affect shale gas production at both global and local scales.Furthermore,a bi-objective optimization algorithm named NSGA-Ⅱ is seamlessly incorporated to opti-mize hydraulic fracturing designs for production boost and cost control.This innovative framework addresses critical limitations often encountered in applying machine learning(ML)to shale gas pro-duction:the challenge of achieving sufficient model accuracy with limited samples,the multidisciplinary expertise required for developing robust ML models,and the need for interpretability in“black-box”models.Validation with field data from the Fuling shale gas field in the Sichuan Basin substantiates the framework's efficacy in enhancing the precision and applicability of data-driven techniques.The test accuracy of the ensemble ML model reached 83%compared to a maximum of 72%of single ML models.The contribution of each geological and engineering factor to the overall production was quantitatively evaluated.Fracturing design optimization raised EUR by 7%-34%under different production and cost tradeoff scenarios.The results empower domain experts to conduct more precise and objective data-driven analyses and optimizations for shale gas production with minimal expertise in data science.
文摘The fracture volume is gradually changed with the depletion of fracture pressure during the production process.However,there are few flowback models available so far that can estimate the fracture volume loss using pressure transient and rate transient data.The initial flowback involves producing back the fracturing fuid after hydraulic fracturing,while the second flowback involves producing back the preloading fluid injected into the parent wells before fracturing of child wells.The main objective of this research is to compare the initial and second flowback data to capture the changes in fracture volume after production and preload processes.Such a comparison is useful for evaluating well performance and optimizing frac-turing operations.We construct rate-normalized pressure(RNP)versus material balance time(MBT)diagnostic plots using both initial and second flowback data(FB;and FBs,respectively)of six multi-fractured horizontal wells completed in Niobrara and Codell formations in DJ Basin.In general,the slope of RNP plot during the FB,period is higher than that during the FB;period,indicating a potential loss of fracture volume from the FB;to the FB,period.We estimate the changes in effective fracture volume(Ver)by analyzing the changes in the RNP slope and total compressibility between these two flowback periods.Ver during FB,is in general 3%-45%lower than that during FB:.We also compare the drive mechanisms for the two flowback periods by calculating the compaction-drive index(CDI),hydrocarbon-drive index(HDI),and water-drive index(WDI).The dominant drive mechanism during both flowback periods is CDI,but its contribution is reduced by 16%in the FB,period.This drop is generally compensated by a relatively higher HDI during this period.The loss of effective fracture volume might be attributed to the pressure depletion in fractures,which occurs during the production period and can extend 800 days.
文摘This study examines the role of maize in food security and economic stability,focusing on its response to climate change and strategies to enhance resilience.Using a qualitative descriptive research methodology,the study analyzes the impact of climate change on global maize production and proposes innovative strategies for sustainability and food security.The agricultural environment is vulnerable to heavy metal toxicity,which is linked to the relationship between soil health and climate change.From 1850 to 2020,the Earth’s temperature increased by 1.1℃,with projections indicating continued warming.This trend has significant economic implications,particularly in developing countries where agriculture employs 69%of the population.Heat waves and droughts represent abiotic stresses faced by maize.Research suggests that high greenhouse gas emissions could lead to a 24%reduction in maize yield by 2030.The study highlights the need to focus on breeding and phenotyping technologies to develop heat-and drought-tolerant maize varieties that use water efficiently.Additionally,strategies such as genomic editing,transcriptome analysis,and maize quality mapping are crucial to addressing these challenges.Developing insect-resistant maize is another objective.This study emphasizes the necessity of ongoing research to improve agricultural productivity and ensure food security,especially in light of global population growth.It also advocates for new regulations to reduce greenhouse gas emissions,which contribute to global warming.
基金the National Natural Science Foundation of China(Grant Nos.52374038 and U23B2089)Innovation Capability Support Program of Shaanxi(Program No.2024ZC-KJXX-064).
文摘This study explores the impact of salinity on fluid replacement during imbibition-driven oil recovery through a series of core self-imbibition experiments.By integrating key parameters such as interfacial tension,contact angle,and oil displacement efficiency,we systematically examine how variations in salinity level,ion type,and ion concentration affect the imbibition process.The results demonstrate that the salinity of the injected fluid exerts a strong influence on the rate and extent of oil recovery.Compared with high-salinity conditions,low-salinity injection,particularly below 5000 mg.L-1,induces pronounced fluctuations in the replacement rate,achieving the highest recovery at approximately 1000 mg·L-1.The interplay between interfacial tension and displacement efficiency is jointly governed by both ion type and concentration.Moreover,changes in ionic composition can alter rock wettability from oil-wet toward water-wet states,thereby enhancing imbibition efficiency.Among the tested ions,Mg2+and SO4²at low concentrations were found to be especially effective in promoting oil displacement.
基金supported by the Sinopec Technology Research and Development Project(No.30000000-22-ZC0607-0235,No.33550000-22-ZC0607-0009)the National Natural Science Foundation of China(No.52334002).
文摘Natural gas hydrate widely exists in the South China Sea as clean energy.A three-phase transition layer widely exists in low permeability Class I hydrates in the Shenhu offshore area.Therefore,taking into account the low-permeability characteristics with an average permeability of 5.5 mD and moderate heterogeneity,a 3-D geological model of heterogeneous Class I hydrate reservoirs with three-phase transition layers is established by Kriging interpolation and stochastic modeling method,and a numerical simulation model is used to describe the depressurization production performance of the reservoir.With the development of depressurization,a specific range of complete decomposition zones appear both in the hydrate and transition layers.The entire decomposition zone of the whole reservoir tends to outward and upward diffusion.There is apparent methane escape in the three-phase transition layer.Due to the improvement of local permeability caused by the phase transition of hydrate dissociation,some methane accumulation occurs at the bottom of the hydrate layer,forming a local methane enrichment zone.The methane migration trends in reservoirs are mainly characterized by movement toward production wells and hydrate layers under the influence of gravity.However,due to the permeability limitation of hydrate reservoirs,many fluids have not been effectively produced and remain in the reservoir.Therefore,to improve the effective pressure drop of the reservoir,the perforation method and pressure reduction method were optimized by analyzing the influencing factors based on the gas production rate.The comparative study demonstrates that perforating through the free gas layer combined with one-time depressurization can enhance the effective depressurization and improve production performance.The gas production rate from perforating through the free gas layer can be twice as high as that from perforating through the transition layer.This study can provide theoretical support for the utilization of marine energy.
基金Mahidol University for the support of a “Scholarship for PhD Student”, Thailandthe the cooperation with the National Science and Technology Development Agency and Mahidol University of “the Scholarship for the Development of High Quality Research Graduates in Science and Technology Project”, Thailand。
文摘Global warming and climate change have made food production through conventional agriculture inefficient, and their effects on livestock and crop cultivation are leading to disruptions in the food supply. The troubles are severe in regions suffering from improper land management and unsustainable practices. The Bio-CircularGreen(BCG) economic model, designed to reduce and recycle resources by using environmentally friendly procedures, has been developed. The Azolla plant represents an interesting model for BCG and for enhancing community networks in Southeast Asia(SEA) because it provides multipurpose materials. Azolla can be used for various applications in agriculture such as biofertilizer and animal feed. However, our understanding and utilization of Azolla are limited. Moreover, collaboration among farmers is insufficient to maximize the benefits of Azolla. In this study, we provide a comprehensive review of the role of Azolla in agriculture. We review the main properties of Azolla as biofertilizers, especially regarding rice production and the interaction with cyanobacteria. For livestock, we discuss procedures to use Azolla in animal feed and evaluate the ingredients of the meal. In addition, we discuss product qualities from livestock treated with Azolla in the diet. This review also describes Azolla-based farming, which is designed for efficient land use and promotes nutrient cycling.Hence, we show that the Azolla plant is one of the key factors for farm-based agroecosystem services which can drive sustainable bioresource management in SEA. Moreover, we also propose the potential development of Azolla to improve its properties as a biofertilizer, a functional feed for animals and humans, and a feedstock for bio-oil production.
