Two types of ultra-high-temperature resistant water-based drilling fluid additives were designed and developed:an ultra-high-temperature resistant salt-tolerant polymer fluid loss reducer,and an ultra-high-temperature...Two types of ultra-high-temperature resistant water-based drilling fluid additives were designed and developed:an ultra-high-temperature resistant salt-tolerant polymer fluid loss reducer,and an ultra-high-temperature resistant micro-nano plugging agent.An ultra-high-temperature resistant water-based drilling fluid system meeting the requirements of ultra-deep well drilling was established.Laboratory test and field application were employed for performance evaluation.The ultra-high-temperature and high-salt resistant polymer fluid loss reducer exhibits a mesh-like membrane structure with numerous cross-linking points,and its high-temperature and high-pressure(HTHP)loss was 28.2 m L after aging at 220℃under saturated salt conditions.The ultra-high-temperature resistant micro-nano plugging agent adaptively filled mud cake pores/fractures through deformation,thus reducing the fluid loss.At elevated temperatures,it transitioned to a viscoelastic state to effectively cement the rock on wellbore wall and enhanced wall stability.The ultra-high-temperature resistant water-based drilling fluid system with a density of 1.6 g/cm^(3)exhibits excellent rheological properties at high temperature and high pressure.Its HTHP fluid loss at 220℃was only 9.6 m L.It maintains a stable performance under high-temperature and high-salt conditions,with a sedimentation factor below 0.52 after holding at high temperature for 7 d,and generates no H_(2)S gas after aging,demonstrating good lubricity and safety.This drilling fluid system has been successfully applied in the 10000-meter ultra-deep well of China,Shenditake 1,in Tarim Oilfield,ensuring the well's successful drilling to a depth of 10910 m.展开更多
Rhegmatogenous retinal detachment(RRD)is a serious ocular condition marked by the separation of the neuroretina from the retinal pigment epithelium(RPE).The pathogenesis of RRD involves intricate molecular and cellula...Rhegmatogenous retinal detachment(RRD)is a serious ocular condition marked by the separation of the neuroretina from the retinal pigment epithelium(RPE).The pathogenesis of RRD involves intricate molecular and cellular mechanisms,including inflammation,cell migration,and the activation of proliferative signaling pathways.One of the most challenging complications of RRD is proliferative vitreoretinopathy(PVR),which refers to the proliferation and contraction of fibrocellular membranes on the retinal surface and in the vitreous cavity.PVR is a major cause of surgical failure in RRD,as it can lead to recurrent retinal detachment and severe vision loss.However,the pathogenesis of PVR is not yet fully understood,and the treatment options are quite limited.Recent advances in analytical techniques have offered valuable insights into the molecular alterations present in the subretinal fluid(SRF)of patients with RRD.This review seeks to consolidate the current knowledge regarding the SRF profile in RRD and PVR,emphasizing potential biomarkers and therapeutic targets.展开更多
The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesi...The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesis.Copper primarily exists as Cu^(+)and Cu^(2+)in hydrothermal solutions,with redox conditions governing their interconversion.In chloride-rich geological fluids,Cu-Cl complexes are considered critical for copper transport.However,the specific types and valence transitions of Cu-Cl complexes under varying hydrothermal conditions remain poorly understood.This study employed in situ Raman spectroscopy to systematically analyze Cu+HCl and CuCl_(2)+K_(2)S_(2)O_(3)/H_(2) systems under saturated vapor pressure at 25-300℃,elucidating the effects of temperature,Cl^(-)concentration,and redox conditions on copper speciation.In the Cu^(+)HCl system,copper dissolved as monovalent Cu-Cl complexes.At high temperatures(>200℃),[CuCl_(2)]^(-)is the dominated species,whereas[CuCl_(3)]^(2-)becomes prevalent at lower temperatures and higher HCl concentrations.For the Cu^(2+)-Cl system,the dominant species transitioned from[Cu(H_(2)O)n]^(2+)(<50℃)to[CuCl_(4)]^(2-)(100℃)and further to[CuCl]^(+)and[CuCl_(2)]^(0) at 300℃.The introduction of reducing agents(K_(2)S_(2)O_(3)/H_(2))facilitated Cu^(2+)→Cu^(+)reduction,thereby stabilizing Cu^(+)-Cl complexes and inducing partial copper precipitation.The behavior of copper in chloriderich hydrothermal fluids observed in this study indicates that high-temperature oxidizing fluids facilitate Cu mobilization,while cooling and redox changes promote deposition and ore minerals formation.展开更多
As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises s...As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.展开更多
When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may aff...When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may affect the initiation and propagation of fractures within brittle materials.Understanding the physical mechanisms leading to failure is crucial for underground engineering applications and geo-energy exploration and storage.We conducted triaxial compression experiments on porous Bentheim sandstone samples at different stress paths and pressure change rates.First,at a constant confining pressure of 35 MPa and pore pressure of 5 MPa,intact cylindrical samples were axially loaded up to about 85%of the peak strength.Subsequently,the axial piston position was fixed,and then either the pore pressure was increased or the confining pressure was decreased at two different rates(0.5 MPa/min or 2 MPa/min),leading to final catastrophic failure.The mechanical results revealed that samples subjected to higher rates of decreasing effective confining pressure exhibited larger stress drop rates,higher slip rates,higher total breakdown work,higher rates of acoustic emissions(AEs)before failure,and higher post-failure AE decay rates.In contrast,the applied stress path did not significantly affect rock failure characteristics.Comparison of located AE events with post-mortem microstructures of deformed samples shows a good agreement.The AE source type determined from the P-wave first-motion polarity shows that shear failure dominated the fracture process when approaching failure.Gutenberg-Richter b-values revealed a significant decrease before failure in all tests.Our results indicate that,in contrast to the stress path,the rate of effective stress change strongly affects fracturing behavior and AE rate changes.展开更多
The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of i...The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of its influence on fluid migration are of crucial importance.While previous studies have revealed that salinity changes can modulate fluid migration,the underlying mechanisms remain poorly understood.We employ molecular dynamics simulations to elucidate how salinity variations in ore-forming fluids modulate the adsorption onto calcite nanopore walls,thereby revealing the microscopic mechanisms governing ore fluid transport through calcite nano-fractures.The results show that the adsorption energy Eint of the solution on the calcite surface increased from -14,948.84±182.48 kcal/mol to -12,144.08±118.2 kcal/mol as salinity increased,which is conducive to the long-range transport of the fluid in the calcite nanopore.展开更多
Formulating oil-based drilling fluids(OBDFs)with an ultra-low oil-to-water ratio(OWR≤60:40)presents a formidable stability challenge due to the maximized interfacial area and intensified stress on the interfacial fil...Formulating oil-based drilling fluids(OBDFs)with an ultra-low oil-to-water ratio(OWR≤60:40)presents a formidable stability challenge due to the maximized interfacial area and intensified stress on the interfacial film under high-temperature,high-density conditions.To address this,we engineered a synergistic stabilization system through molecular and colloidal design.A novel hyperbranched polyamide emulsifier(epoxidized soybean oil polyamide)(ESOP),synthesized from epoxidized soybean oil,exhibits superior thermal stability and interfacial activity due to its hyperbranched architecture.Combined with calcium petroleum sulfonate(CPS)and hydrophobic nanosilica(HNs),it enables a high-performance OBDF with an ultra-low OWR of 60:40.The results show that the optimized formula achieves an excellent demulsification voltage of 1290 V,an ultra-low HTHP fluid loss of 1.5 mL,a yield point of 12.9 Pa,and a superior sag factor(SF)of 0.504,outperforming both base and commercial systems.Mechanistic studies reveal a multiscale stabilization strategy involving a dense composite interfacial film,Pickering stabilization,a 3D network,and a unique thermally triggered self-reinforcement effect.This work not only provides a cost-effective OBDF formulation but,more importantly,establishes a molecular topology engineering paradigm for stabilizing complex industrial fluids under extreme conditions.展开更多
While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model...While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model incorporating rate-and-state friction laws to investigate fault reactivation mechanisms during early-stage CO_(2)injection.The competing effects of pore pressure diffusion and fluid pressurization are systematically investigated,considering three key factors:permeability variations within fault damage zones,normal stress variation coefficients,and injection parameters.Numerical simulations reveal that slower CO_(2)migration causes limited pressure perturbation(<0.3 MPa over 15 d)compared to single-phase fluid injection.Fluid pressurization enhances fault strength and delays reactivation,though this stabilizing effect diminishes in low-permeability damage zones.Highly permeable damage zones promote larger rupture areas despite strengthening from pressurization,as reduced effective stress accelerates failure.Paradoxically,while fluid pressurization increases fault strength,it simultaneously elevates seismic risk through amplified stress drops during slip events.Temporal analysis shows that fluid pressurization dominates initial fault response,while sustained pore pressure diffusion ultimately drives reactivation.Increased normal stress variation coefficients and injection rates accelerate localized rupture initiation but restrict propagation due to non-critically stressed states.This discrepancy demonstrates that regions with positive Coulomb failure stress changes do not correlate well with actual slip zones.These findings highlight the critical interplay between transient pressurization effects and progressive pressure diffusion during early CO_(2)injection phases,providing crucial insights for seismic risk management in CO_(2)storage projects.展开更多
There is a need for accurate prediction of heat and mass transfer in aerodynamically designed,non-Newtonian nanofluids across aerodynamically designed,high-flux biomedical micro-devices for thermal management and reac...There is a need for accurate prediction of heat and mass transfer in aerodynamically designed,non-Newtonian nanofluids across aerodynamically designed,high-flux biomedical micro-devices for thermal management and reactive coating processes,but existing work is not uncharacteristically remiss regarding viscoelasticity,radiative heating,viscous dissipation,and homogeneous–heterogeneous reactions within a single scheme that is calibrated.This research investigates the flow of Williamson nanofluid across a dynamically wedged surface under conditions that include viscous dissipation,thermal radiation,and homogeneous-heterogeneous reactions.The paper develops a detailed mathematical approach that utilizes boundary layers to transform partial differential equations into ordinary differential equations using similarity transformations.RK4 is the technique for gaining numerical solutions,but with the addition of ANNs,there is an improvement in prediction accuracy and computational efficiency.The study investigates the influence of wedge angle parameter,along with Weissenberg number,thermal radiation parameter and Brownian motion parameter,and Schmidt number,on velocity distribution,temperature distribution,and concentra-tion distribution.Enhanced Weissenberg numbers enhance viscoelastic responses that modify velocity patterns,but radiation parameters and thermophoresis have key impacts on thermal transfer phenomena.This research develops findings that are of enormous application in aerospace,biomedical(artificial hearts and drug delivery),and industrial cooling technology applications.New findings on non-Newtonian nanofluids under full flow systems are included in this work to enhance heat transfer methods in novel fluid-based systems.展开更多
Detecting biomarkers in body fluids by optical lateral flow immune assay(LFIA) technology provides rapid access to disease information for early diagnosis.LFIA is based on an antigen-antibody reaction and is rapidly b...Detecting biomarkers in body fluids by optical lateral flow immune assay(LFIA) technology provides rapid access to disease information for early diagnosis.LFIA is based on an antigen-antibody reaction and is rapidly becoming the preferred choice of physicians and patients for point-of-care testing due to its simplicity,cost-effectiveness,and rapid detection.Observing the optical signal change from the colloidal gold of the traditional LFIA strip has been widely applied for various biomarkers detection in body fluids.Despite the significant progress,rapid real-time detection of color changes in the colloidal gold by the naked eye still faces many limitations,such as large errors and the inability to quantify and accurately detect.New optical LFIA strip technology has emerged in recent years to extend its application scenarios for achieving quantitative detection such as fluorescence,afterglow,and chemiluminescence.Herein,we summarized the development of optical LFIA technology from single to hyphenated optical signals for biomarkers detection in body fluids from invasive and non-invasive sources.Moreover,the challenge and outlook of optical LFIA strip technology are highlighted to inspire the designing of next-generation diagnostic platforms.展开更多
Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed f...Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed flow-through electrochemical reactors(FERs)primarily based on porous electrodes,where the pore structure significantly impacts the electrochemical reaction.Therefore,this study systematically investigated the impact of different pore sizes on the fluid dynamics,current potential distribution,mass transfer processes,and degradation performance of FERs.Computational Fluid Dynamics(CFD)results indicated that smaller pore sizes(10μm,30μm,and 60μm)significantly enhanced convective effects within the fluid,reduced short fluid paths and dead volume regions within the microchannels,and facilitated mass transfer processes.Additionally,smaller pore sizes were conducive to a uniform distribution of current density.Furthermore,Fe(CN)_(6)^(4−)oxidation experiments revealed that the current density at a pore size of 160μm was notably lower than that at 10μm,indicating slower mass transfer of Fe(CN)_(6)^(4−)within larger channels.Calculations based on experimental results demonstrated that the mass transfer rate at a pore size of 10μm was six times than that at 160μm,further confirming the enhancing effect of smaller pore sizes on the mass transfer process.Lastly,experiments on tetracycline degradation showed that at a residence time of 90 s,the removal efficiencies of tetracycline were 80%and 39.1%for porous electrodes with pore sizes of 10μm and 160μm,respectively,demonstrating the superior removal efficiency of smaller pore sizes for tetracycline degradation.展开更多
The airflow mechanics in adult nasal airways,whether healthy or abnormal,are extensively studied and investigated,but the flow mechanics in child nasal airways remain underexplored.This study investigates the airflow ...The airflow mechanics in adult nasal airways,whether healthy or abnormal,are extensively studied and investigated,but the flow mechanics in child nasal airways remain underexplored.This study investigates the airflow mechanics in the child’s nasal upper airway with adenoid hypertrophy,with an adenoid nasopharyngeal ratio(AN of 0.9),under cyclic inhalation and exhalation.An inlet respiratory cycle with three different flow rates(3.2 L/min calm breathing,8.6 L/min normal breathing,and 19.3 L/min intensive breathing)was simulated by using the computational fluid dynamics approach.To better capture the interaction between airflow and the flexible airway tissue,fluid-structure interaction analysis was performed at the normal breathing rate.Comparing the airflow dynamics during inhalation and exhalation,the pressure drops,nasal resistance,and wall shear stress show significant differences in the nasopharyngeal region for all different flow rates.This observation suggests that the inertial effect associated with the transient flow is important during exhalation and inhalation.Furthermore,the considerable temporal variation in flow rate distribution across a specific cross-section of the nasal airway highlights the critical role of transient data in virtual surgery planning and data for clinical decisions.展开更多
Supercritical fluids play a crucial role in material transport within Earth's deep interior.Investigating the pressure-dependent atomic structures and transport properties of such fluids is essential for understan...Supercritical fluids play a crucial role in material transport within Earth's deep interior.Investigating the pressure-dependent atomic structures and transport properties of such fluids is essential for understanding their petrological,chemical,and geophysical behaviors.In this study,we employed first-principles molecular dynamics simulations to explore the structures,self-diffusion coefficients(D),and viscosities(η)of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids under conditions of 2000 K and 3-10 GPa,with water contents of 30 wt% and 50 wt%.Our calculations indicate that at a water content of 30 wt%,Q^(2) and Q^(3) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species(n represents the number of bridging oxygens connected to Si/Al)show minimal changes.At a water content of 50 wt%,Q^(2) and Q^(0) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species show minimal changes.At both water contents,Si-O-H and molecular water in the system exhibit negative pressure dependence,suggesting that the migration of supercritical fluids from deep to shallow regions is accompanied by the release of water.The self-diffusion coefficients in the supercritical NaAlSi_(3)O_(8)-H_(2)O fluid follow the order D_(Na)≈D_(H)>D_(O)>D_(Al)≈D_(Si),with an overall weak negative pressure dependence.By comparing the viscosities of anhydrous and hydrous silicate melts from previous studies,we found that the addition of water caused a transition from negative to positive pressure dependence of viscosity,corresponding to a structural change from polymerization to depolymerization.Additionally,we calculated the fluid mobility Δp/η of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids and found that their mobility is several orders of magnitude higher than that of basalt melt and is also significantly greater than that of carbonate melt.As supercritical fluids ascend from deeper to shallower regions,their mobility is further enhanced,significantly contributing to the transport of elements from subducting slabs to the overlying mantle wedge.展开更多
With the efficient and intelligent development of computer-based big data processing,applying machine learning methods to the processing and interpretation of logging data in the field of geophysical well logging has ...With the efficient and intelligent development of computer-based big data processing,applying machine learning methods to the processing and interpretation of logging data in the field of geophysical well logging has broad potential for improving production efficiency.Currently,the Jiyuan Oilfield in the Ordos Basin relies mainly on manual reprocessing and interpretation of old well logging data to identify different fluid types in low-contrast reservoirs,guiding subsequent production work.This study uses well logging data from the Chang 1 reservoir,partitioning the dataset based on individual wells for model training and testing.A deep learning model for intelligent reservoir fluid identification was constructed by incorporating the focal loss function.Comparative validations with five other models,including logistic regression(LR),naive Bayes(NB),gradient boosting decision trees(GBDT),random forest(RF),and support vector machine(SVM),show that this model demonstrates superior identification performance and significantly improves the accuracy of identifying oil-bearing fluids.Mutual information analysis reveals the model's differential dependency on various logging parameters for reservoir fluid identification.This model provides important references and a basis for conducting regional studies and revisiting old wells,demonstrating practical value that can be widely applied.展开更多
In drilling ultra-deep wells,the drilling fluid circulation usually causes erosion damage to downhole casing and drilling tools.However,the extent and process of this damage to the downhole tools is intricate and less...In drilling ultra-deep wells,the drilling fluid circulation usually causes erosion damage to downhole casing and drilling tools.However,the extent and process of this damage to the downhole tools is intricate and less understood.In order to systematically evaluate and clarify this damage process for different types of drilling fluid contamination,this research uses a high-temperature drilling fluid damage device to simulate the damage caused to the casing/drilling tools by various drilling fluid under a field thermal gradient.The results show that the drilling fluid residues are mainly solid-phase particles and organic components.The degree of casing/tool damage decreases with an increase in bottom hole temperature,and the casing/tool is least damaged within a temperature range of 150–180°C.Moreover,the surface of the casing/tool damaged by different types of drilling fluid shows different roughness,and the wettability of drilling fluid on the casing/tool surface increases with an increase in the degree of roughness.Oil-based drilling fluid have the strongest adhesion contamination on casing/drilling tools.In contrast,polysulfonated potassium drilling fluid and super-micro drilling fluid have the most potent erosion damage on casing/drilling tools.By analyzing the damage mechanism,it was established that the damage was mainly dominated by the abrasive wearing from solid-phase particles in concert with corrosion ions in drilling fluid,with solids producing many abrasion marks and corrosive ions causing a large number of pits.Clarifying drilling fluid's contamination and damage mechanism is significant in guiding the wellbore cleaning process and cutting associated costs.展开更多
Identifying the cause of respiratory tract infections is important for reducing the burden of diagnosis and treatment.To assess viral etiologies of hospitalized patients with pulmonary infection,bronchoalveolar lavage...Identifying the cause of respiratory tract infections is important for reducing the burden of diagnosis and treatment.To assess viral etiologies of hospitalized patients with pulmonary infection,bronchoalveolar lavage fluid(BALF)specimens were collected from non-COVID-19 adult patients(n=333,including patients with lower respiratory tract infection,tuberculosis,lung cancer,and pulmonary nodules)between November 2020 and November 2021.Multiple common respiratory pathogens were detected using multiplex reverse-transcription polymerase chain reaction.The result showed that at least one virus was identified in 35.44%(118/333)of the cases.Among these,influenza virus was the most commonly identified,followed by the parainfluenza virus,coronavirus,human rhinoviruses,and human respiratory syncytial viruses.The tuberculosis group demonstrated the highest viral detection rate,yet paradoxically exhibited the lowest co-infection rate.In contrast,the highest co-infection frequency was observed in the pulmonary nodules group.Patients with viral infections exhibited more severe clinical symptoms compared to those without detected viral infections.However,this observation was only noted in the lower respiratory tract infection group among the different disease groups.Notably,among patients infected with a specific virus,there were no significant differences in viral load between single and co-infections.Our study identified the major causative agents in hospitalized adult patients with pulmonary infection,offering insights for precise disease diagnosis and the prevention of unnecessary use of antimicrobial drugs.展开更多
Temperature is a critical factor influencing the performance of coal catalytic hydrogasification in bubbling fluidized bed gasifiers.Numerical simulations at various temperatures(1023 K,1073 K,1123 K,and 1173 K)are co...Temperature is a critical factor influencing the performance of coal catalytic hydrogasification in bubbling fluidized bed gasifiers.Numerical simulations at various temperatures(1023 K,1073 K,1123 K,and 1173 K)are conducted to elucidate the mechanisms by which temperature affects bubble size,global reaction performance,and particle-scale reactivity.The simulation results indicate that bubble size increases at elevated temperatures,while H_(2)-char hydrogasification reactivity is enhanced.Particle trajectory analyses reveal that particles sized between 100 and 250μm undergo intense char hydrogasification in the dense phase,contributing to the formation of hot spots.To assess the impact of temperature on the particle-scale flow-transfer-reaction process,the dimensionless quantities of Reynolds,Nusselt,and Sherwood numbers,along with the solids dispersion coefficient,are calculated.It is found that higher temperatures inhibit bubble-induced mass and heat transfer.In general,3 MPa,1123 K,and 3-4 fluidization numbers are identified as the optimal conditions for particles ranging from 0 to350μm.These findings provide valuable insights into the inherent interactions between temperature and gas-particle reaction.展开更多
Aiming at the leakage problem in the compact sandstone drilling of the Keziluoyi Formation in South-west Tarim,Nano-core-emulsion was prepared by coating modified nano-SiO_(2) with nano-emulsion,its particle size D50 ...Aiming at the leakage problem in the compact sandstone drilling of the Keziluoyi Formation in South-west Tarim,Nano-core-emulsion was prepared by coating modified nano-SiO_(2) with nano-emulsion,its particle size D50 is about 100 nm,with good dispersion stability.When 0.8%Nano-core-emulsion is added to 5%bentonite slurry,the fluid loss can be reduced by 40%,and the filter cake thickness can be reduced by 84%.Using a Nano-core-emulsion to optimize the plugging performance of potassium pol-ysulfonate drilling fluid can reduce the fluid loss of the drilling fluid by 52%,the resulting filter cake is dense and tough,and the thickness is reduced by 40%.Using the pressure conduction method to evaluate the plugging rate,the plugging rate of the drilling fluid of the Nano-core-emulsion on the core of the Keziluoyi Formation is 63.4%,which is 20.9%higher than that of the field drilling fluid.According to microscopic examination and CT scanning analysis,the material has the plugging characteristics of"inner rigid support+outer soft deformation"and has demonstrated good field application results.展开更多
Particle-fluid two-phase flows in rock fractures and fracture networks play a pivotal role in determining the efficiency and effectiveness of hydraulic fracturing operations,a vital component in unconventional oil and...Particle-fluid two-phase flows in rock fractures and fracture networks play a pivotal role in determining the efficiency and effectiveness of hydraulic fracturing operations,a vital component in unconventional oil and gas extraction.Central to this phenomenon is the transport of proppants,tiny solid particles injected into the fractures to prevent them from closing once the injection is stopped.However,effective transport and deposition of proppant is critical in keeping fracture pathways open,especially in lowpermeability reservoirs.This review explores,then quantifies,the important role of fluid inertia and turbulent flows in governing proppant transport.While traditional models predominantly assume and then characterise flow as laminar,this may not accurately capture the complexities inherent in realworld hydraulic fracturing and proppant emplacement.Recent investigations highlight the paramount importance of fluid inertia,especially at the high Reynolds numbers typically associated with fracturing operations.Fluid inertia,often overlooked,introduces crucial forces that influence particle settling velocities,particle-particle interactions,and the eventual deposition of proppants within fractures.With their inherent eddies and transient and chaotic nature,turbulent flows introduce additional complexities to proppant transport,crucially altering proppant settling velocities and dispersion patterns.The following comprehensive survey of experimental,numerical,and analytical studies elucidates controls on the intricate dynamics of proppant transport under fluid inertia and turbulence-towards providing a holistic understanding of the current state-of-the-art,guiding future research directions,and optimising hydraulic fracturing practices.展开更多
This study comprehensively uses various methods such as production dynamic analysis,fluid inclusion thermometry and carbon-oxygen isotopic compositions testing,based on outcrop,core,well-logging,3D seismic,geochemistr...This study comprehensively uses various methods such as production dynamic analysis,fluid inclusion thermometry and carbon-oxygen isotopic compositions testing,based on outcrop,core,well-logging,3D seismic,geochemistry experiment and production test data,to systematically explore the control mechanisms of structure and fluid on the scale,quality,effectiveness and connectivity of ultra-deep fault-controlled carbonate fractured-vuggy reservoirs in the Tarim Basin.The results show that reservoir scale is influenced by strike-slip fault scale,structural position,and mechanical stratigraphy.Larger faults tend to correspond to larger reservoir scales.The reservoir scale of contractional overlaps is larger than that of extensional overlaps,while pure strike-slip segments are small.The reservoir scale is enhanced at fault intersection,bend,and tip segments.Vertically,the heterogeneity of reservoir development is controlled by mechanical stratigraphy,with strata of higher brittleness indices being more conducive to the development of fractured-vuggy reservoirs.Multiple phases of strike-slip fault activity and fluid alterations contribute to fractured-vuggy reservoir effectiveness evolution and heterogeneity.Meteoric water activity during the Late Caledonian to Early Hercynian period was the primary phase of fractured-vuggy reservoir formation.Hydrothermal activity in the Late Hercynian period further intensified the heterogeneity of effective reservoir space distribution.The study also reveals that fractured-vuggy reservoir connectivity is influenced by strike-slip fault structural position and present in-situ stress field.The reservoir connectivity of extensional overlaps is larger than that of pure strike-slip segments,while contractional overlaps show worse reservoir connectivity.Additionally,fractured-vuggy reservoirs controlled by strike-slip faults that are nearly parallel to the present in-situ stress direction exhibit excellent connectivity.Overall,high-quality reservoirs are distributed at the fault intersection of extensional overlaps,the central zones of contractional overlaps,pinnate fault zones at intersection,bend,and tip segments of pure strike-slip segments.Vertically,they are concentrated in mechanical stratigraphy with high brittleness indices.展开更多
基金Supported by the CNPC Science and Technology Project(2022ZG06)Xinjiang Uygur Autonomous Region Science and Technology Innovation Talent Project(2024TSYCCX0061)。
文摘Two types of ultra-high-temperature resistant water-based drilling fluid additives were designed and developed:an ultra-high-temperature resistant salt-tolerant polymer fluid loss reducer,and an ultra-high-temperature resistant micro-nano plugging agent.An ultra-high-temperature resistant water-based drilling fluid system meeting the requirements of ultra-deep well drilling was established.Laboratory test and field application were employed for performance evaluation.The ultra-high-temperature and high-salt resistant polymer fluid loss reducer exhibits a mesh-like membrane structure with numerous cross-linking points,and its high-temperature and high-pressure(HTHP)loss was 28.2 m L after aging at 220℃under saturated salt conditions.The ultra-high-temperature resistant micro-nano plugging agent adaptively filled mud cake pores/fractures through deformation,thus reducing the fluid loss.At elevated temperatures,it transitioned to a viscoelastic state to effectively cement the rock on wellbore wall and enhanced wall stability.The ultra-high-temperature resistant water-based drilling fluid system with a density of 1.6 g/cm^(3)exhibits excellent rheological properties at high temperature and high pressure.Its HTHP fluid loss at 220℃was only 9.6 m L.It maintains a stable performance under high-temperature and high-salt conditions,with a sedimentation factor below 0.52 after holding at high temperature for 7 d,and generates no H_(2)S gas after aging,demonstrating good lubricity and safety.This drilling fluid system has been successfully applied in the 10000-meter ultra-deep well of China,Shenditake 1,in Tarim Oilfield,ensuring the well's successful drilling to a depth of 10910 m.
文摘Rhegmatogenous retinal detachment(RRD)is a serious ocular condition marked by the separation of the neuroretina from the retinal pigment epithelium(RPE).The pathogenesis of RRD involves intricate molecular and cellular mechanisms,including inflammation,cell migration,and the activation of proliferative signaling pathways.One of the most challenging complications of RRD is proliferative vitreoretinopathy(PVR),which refers to the proliferation and contraction of fibrocellular membranes on the retinal surface and in the vitreous cavity.PVR is a major cause of surgical failure in RRD,as it can lead to recurrent retinal detachment and severe vision loss.However,the pathogenesis of PVR is not yet fully understood,and the treatment options are quite limited.Recent advances in analytical techniques have offered valuable insights into the molecular alterations present in the subretinal fluid(SRF)of patients with RRD.This review seeks to consolidate the current knowledge regarding the SRF profile in RRD and PVR,emphasizing potential biomarkers and therapeutic targets.
基金jointly funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant No.XDA0430301)the National Natural Science Foundation of China(grant Nos.42130109,41973059)。
文摘The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesis.Copper primarily exists as Cu^(+)and Cu^(2+)in hydrothermal solutions,with redox conditions governing their interconversion.In chloride-rich geological fluids,Cu-Cl complexes are considered critical for copper transport.However,the specific types and valence transitions of Cu-Cl complexes under varying hydrothermal conditions remain poorly understood.This study employed in situ Raman spectroscopy to systematically analyze Cu+HCl and CuCl_(2)+K_(2)S_(2)O_(3)/H_(2) systems under saturated vapor pressure at 25-300℃,elucidating the effects of temperature,Cl^(-)concentration,and redox conditions on copper speciation.In the Cu^(+)HCl system,copper dissolved as monovalent Cu-Cl complexes.At high temperatures(>200℃),[CuCl_(2)]^(-)is the dominated species,whereas[CuCl_(3)]^(2-)becomes prevalent at lower temperatures and higher HCl concentrations.For the Cu^(2+)-Cl system,the dominant species transitioned from[Cu(H_(2)O)n]^(2+)(<50℃)to[CuCl_(4)]^(2-)(100℃)and further to[CuCl]^(+)and[CuCl_(2)]^(0) at 300℃.The introduction of reducing agents(K_(2)S_(2)O_(3)/H_(2))facilitated Cu^(2+)→Cu^(+)reduction,thereby stabilizing Cu^(+)-Cl complexes and inducing partial copper precipitation.The behavior of copper in chloriderich hydrothermal fluids observed in this study indicates that high-temperature oxidizing fluids facilitate Cu mobilization,while cooling and redox changes promote deposition and ore minerals formation.
基金supported by the National Natural Science Foundation of China(No.12372233)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.25GH01020005)the“111 Project”of China(No.B17037)。
文摘As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.
文摘When a porous rock is subjected to overall compressive loading,either increasing pore pressure or decreasing confining pressure could result in rock failure.The stress path and the applied pressure change rate may affect the initiation and propagation of fractures within brittle materials.Understanding the physical mechanisms leading to failure is crucial for underground engineering applications and geo-energy exploration and storage.We conducted triaxial compression experiments on porous Bentheim sandstone samples at different stress paths and pressure change rates.First,at a constant confining pressure of 35 MPa and pore pressure of 5 MPa,intact cylindrical samples were axially loaded up to about 85%of the peak strength.Subsequently,the axial piston position was fixed,and then either the pore pressure was increased or the confining pressure was decreased at two different rates(0.5 MPa/min or 2 MPa/min),leading to final catastrophic failure.The mechanical results revealed that samples subjected to higher rates of decreasing effective confining pressure exhibited larger stress drop rates,higher slip rates,higher total breakdown work,higher rates of acoustic emissions(AEs)before failure,and higher post-failure AE decay rates.In contrast,the applied stress path did not significantly affect rock failure characteristics.Comparison of located AE events with post-mortem microstructures of deformed samples shows a good agreement.The AE source type determined from the P-wave first-motion polarity shows that shear failure dominated the fracture process when approaching failure.Gutenberg-Richter b-values revealed a significant decrease before failure in all tests.Our results indicate that,in contrast to the stress path,the rate of effective stress change strongly affects fracturing behavior and AE rate changes.
基金financed jointly by the National Major Science and Technology Special Project on Deep Earth Exploration(2024ZD1001701-5)the National Natural Science Foundation of China(42472127,42172086)+2 种基金the Yunnan Major Project of Basic Research(202401BN070001-002)Yunnan Mineral Resources Prediction and Evaluation Engineering Research Center(2011)Innovation Team Program of Kunming University of Science and Technology,Yunnan Province。
文摘The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of its influence on fluid migration are of crucial importance.While previous studies have revealed that salinity changes can modulate fluid migration,the underlying mechanisms remain poorly understood.We employ molecular dynamics simulations to elucidate how salinity variations in ore-forming fluids modulate the adsorption onto calcite nanopore walls,thereby revealing the microscopic mechanisms governing ore fluid transport through calcite nano-fractures.The results show that the adsorption energy Eint of the solution on the calcite surface increased from -14,948.84±182.48 kcal/mol to -12,144.08±118.2 kcal/mol as salinity increased,which is conducive to the long-range transport of the fluid in the calcite nanopore.
基金supported by the Key Research and Development Program Project of Hubei Province(2023BCB070).
文摘Formulating oil-based drilling fluids(OBDFs)with an ultra-low oil-to-water ratio(OWR≤60:40)presents a formidable stability challenge due to the maximized interfacial area and intensified stress on the interfacial film under high-temperature,high-density conditions.To address this,we engineered a synergistic stabilization system through molecular and colloidal design.A novel hyperbranched polyamide emulsifier(epoxidized soybean oil polyamide)(ESOP),synthesized from epoxidized soybean oil,exhibits superior thermal stability and interfacial activity due to its hyperbranched architecture.Combined with calcium petroleum sulfonate(CPS)and hydrophobic nanosilica(HNs),it enables a high-performance OBDF with an ultra-low OWR of 60:40.The results show that the optimized formula achieves an excellent demulsification voltage of 1290 V,an ultra-low HTHP fluid loss of 1.5 mL,a yield point of 12.9 Pa,and a superior sag factor(SF)of 0.504,outperforming both base and commercial systems.Mechanistic studies reveal a multiscale stabilization strategy involving a dense composite interfacial film,Pickering stabilization,a 3D network,and a unique thermally triggered self-reinforcement effect.This work not only provides a cost-effective OBDF formulation but,more importantly,establishes a molecular topology engineering paradigm for stabilizing complex industrial fluids under extreme conditions.
基金funded by Joint Funds of the National Natural Science Foundation of China(Grant No.U23A20671)the Major Project of Inner Mongolia Science and Technology(Grant No.2021ZD0034)the Creative Groups of Natural Science Foundation of Hubei Province,China(Grant No.2021CFA030).
文摘While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model incorporating rate-and-state friction laws to investigate fault reactivation mechanisms during early-stage CO_(2)injection.The competing effects of pore pressure diffusion and fluid pressurization are systematically investigated,considering three key factors:permeability variations within fault damage zones,normal stress variation coefficients,and injection parameters.Numerical simulations reveal that slower CO_(2)migration causes limited pressure perturbation(<0.3 MPa over 15 d)compared to single-phase fluid injection.Fluid pressurization enhances fault strength and delays reactivation,though this stabilizing effect diminishes in low-permeability damage zones.Highly permeable damage zones promote larger rupture areas despite strengthening from pressurization,as reduced effective stress accelerates failure.Paradoxically,while fluid pressurization increases fault strength,it simultaneously elevates seismic risk through amplified stress drops during slip events.Temporal analysis shows that fluid pressurization dominates initial fault response,while sustained pore pressure diffusion ultimately drives reactivation.Increased normal stress variation coefficients and injection rates accelerate localized rupture initiation but restrict propagation due to non-critically stressed states.This discrepancy demonstrates that regions with positive Coulomb failure stress changes do not correlate well with actual slip zones.These findings highlight the critical interplay between transient pressurization effects and progressive pressure diffusion during early CO_(2)injection phases,providing crucial insights for seismic risk management in CO_(2)storage projects.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(No.RS-2025-02315209).
文摘There is a need for accurate prediction of heat and mass transfer in aerodynamically designed,non-Newtonian nanofluids across aerodynamically designed,high-flux biomedical micro-devices for thermal management and reactive coating processes,but existing work is not uncharacteristically remiss regarding viscoelasticity,radiative heating,viscous dissipation,and homogeneous–heterogeneous reactions within a single scheme that is calibrated.This research investigates the flow of Williamson nanofluid across a dynamically wedged surface under conditions that include viscous dissipation,thermal radiation,and homogeneous-heterogeneous reactions.The paper develops a detailed mathematical approach that utilizes boundary layers to transform partial differential equations into ordinary differential equations using similarity transformations.RK4 is the technique for gaining numerical solutions,but with the addition of ANNs,there is an improvement in prediction accuracy and computational efficiency.The study investigates the influence of wedge angle parameter,along with Weissenberg number,thermal radiation parameter and Brownian motion parameter,and Schmidt number,on velocity distribution,temperature distribution,and concentra-tion distribution.Enhanced Weissenberg numbers enhance viscoelastic responses that modify velocity patterns,but radiation parameters and thermophoresis have key impacts on thermal transfer phenomena.This research develops findings that are of enormous application in aerospace,biomedical(artificial hearts and drug delivery),and industrial cooling technology applications.New findings on non-Newtonian nanofluids under full flow systems are included in this work to enhance heat transfer methods in novel fluid-based systems.
基金supported by the National Natural Science Foundation of China (Nos.22234005,22494632,22404081)the Natural Science Foundation of Jiangsu Province (Nos.BK20222015,BK20240534)。
文摘Detecting biomarkers in body fluids by optical lateral flow immune assay(LFIA) technology provides rapid access to disease information for early diagnosis.LFIA is based on an antigen-antibody reaction and is rapidly becoming the preferred choice of physicians and patients for point-of-care testing due to its simplicity,cost-effectiveness,and rapid detection.Observing the optical signal change from the colloidal gold of the traditional LFIA strip has been widely applied for various biomarkers detection in body fluids.Despite the significant progress,rapid real-time detection of color changes in the colloidal gold by the naked eye still faces many limitations,such as large errors and the inability to quantify and accurately detect.New optical LFIA strip technology has emerged in recent years to extend its application scenarios for achieving quantitative detection such as fluorescence,afterglow,and chemiluminescence.Herein,we summarized the development of optical LFIA technology from single to hyphenated optical signals for biomarkers detection in body fluids from invasive and non-invasive sources.Moreover,the challenge and outlook of optical LFIA strip technology are highlighted to inspire the designing of next-generation diagnostic platforms.
基金supported by the National Natural Science Foundation of China(Nos.U22A20241 and 21876105)Shaanxi“Scientist&Engineer”Team(No.2023KXJ-131)Xianyang Key S&T Special Projects(No.L2023-ZDKJ-QCY-SXGG-GY-007).
文摘Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed flow-through electrochemical reactors(FERs)primarily based on porous electrodes,where the pore structure significantly impacts the electrochemical reaction.Therefore,this study systematically investigated the impact of different pore sizes on the fluid dynamics,current potential distribution,mass transfer processes,and degradation performance of FERs.Computational Fluid Dynamics(CFD)results indicated that smaller pore sizes(10μm,30μm,and 60μm)significantly enhanced convective effects within the fluid,reduced short fluid paths and dead volume regions within the microchannels,and facilitated mass transfer processes.Additionally,smaller pore sizes were conducive to a uniform distribution of current density.Furthermore,Fe(CN)_(6)^(4−)oxidation experiments revealed that the current density at a pore size of 160μm was notably lower than that at 10μm,indicating slower mass transfer of Fe(CN)_(6)^(4−)within larger channels.Calculations based on experimental results demonstrated that the mass transfer rate at a pore size of 10μm was six times than that at 160μm,further confirming the enhancing effect of smaller pore sizes on the mass transfer process.Lastly,experiments on tetracycline degradation showed that at a residence time of 90 s,the removal efficiencies of tetracycline were 80%and 39.1%for porous electrodes with pore sizes of 10μm and 160μm,respectively,demonstrating the superior removal efficiency of smaller pore sizes for tetracycline degradation.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0707601).
文摘The airflow mechanics in adult nasal airways,whether healthy or abnormal,are extensively studied and investigated,but the flow mechanics in child nasal airways remain underexplored.This study investigates the airflow mechanics in the child’s nasal upper airway with adenoid hypertrophy,with an adenoid nasopharyngeal ratio(AN of 0.9),under cyclic inhalation and exhalation.An inlet respiratory cycle with three different flow rates(3.2 L/min calm breathing,8.6 L/min normal breathing,and 19.3 L/min intensive breathing)was simulated by using the computational fluid dynamics approach.To better capture the interaction between airflow and the flexible airway tissue,fluid-structure interaction analysis was performed at the normal breathing rate.Comparing the airflow dynamics during inhalation and exhalation,the pressure drops,nasal resistance,and wall shear stress show significant differences in the nasopharyngeal region for all different flow rates.This observation suggests that the inertial effect associated with the transient flow is important during exhalation and inhalation.Furthermore,the considerable temporal variation in flow rate distribution across a specific cross-section of the nasal airway highlights the critical role of transient data in virtual surgery planning and data for clinical decisions.
基金funded by National Natural Science Foundation of China(42373033,Yicheng Sun)Fundamental Research Funds for the Central Universities(B240201111,Yicheng Sun)。
文摘Supercritical fluids play a crucial role in material transport within Earth's deep interior.Investigating the pressure-dependent atomic structures and transport properties of such fluids is essential for understanding their petrological,chemical,and geophysical behaviors.In this study,we employed first-principles molecular dynamics simulations to explore the structures,self-diffusion coefficients(D),and viscosities(η)of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids under conditions of 2000 K and 3-10 GPa,with water contents of 30 wt% and 50 wt%.Our calculations indicate that at a water content of 30 wt%,Q^(2) and Q^(3) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species(n represents the number of bridging oxygens connected to Si/Al)show minimal changes.At a water content of 50 wt%,Q^(2) and Q^(0) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species show minimal changes.At both water contents,Si-O-H and molecular water in the system exhibit negative pressure dependence,suggesting that the migration of supercritical fluids from deep to shallow regions is accompanied by the release of water.The self-diffusion coefficients in the supercritical NaAlSi_(3)O_(8)-H_(2)O fluid follow the order D_(Na)≈D_(H)>D_(O)>D_(Al)≈D_(Si),with an overall weak negative pressure dependence.By comparing the viscosities of anhydrous and hydrous silicate melts from previous studies,we found that the addition of water caused a transition from negative to positive pressure dependence of viscosity,corresponding to a structural change from polymerization to depolymerization.Additionally,we calculated the fluid mobility Δp/η of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids and found that their mobility is several orders of magnitude higher than that of basalt melt and is also significantly greater than that of carbonate melt.As supercritical fluids ascend from deeper to shallower regions,their mobility is further enhanced,significantly contributing to the transport of elements from subducting slabs to the overlying mantle wedge.
基金supported by a project of the Shaanxi Youth Science and Technology Star(2021KJXX-87)public welfare geological survey projects of Shaanxi Institute of Geologic Survey(20180301,201918 and 202103)。
文摘With the efficient and intelligent development of computer-based big data processing,applying machine learning methods to the processing and interpretation of logging data in the field of geophysical well logging has broad potential for improving production efficiency.Currently,the Jiyuan Oilfield in the Ordos Basin relies mainly on manual reprocessing and interpretation of old well logging data to identify different fluid types in low-contrast reservoirs,guiding subsequent production work.This study uses well logging data from the Chang 1 reservoir,partitioning the dataset based on individual wells for model training and testing.A deep learning model for intelligent reservoir fluid identification was constructed by incorporating the focal loss function.Comparative validations with five other models,including logistic regression(LR),naive Bayes(NB),gradient boosting decision trees(GBDT),random forest(RF),and support vector machine(SVM),show that this model demonstrates superior identification performance and significantly improves the accuracy of identifying oil-bearing fluids.Mutual information analysis reveals the model's differential dependency on various logging parameters for reservoir fluid identification.This model provides important references and a basis for conducting regional studies and revisiting old wells,demonstrating practical value that can be widely applied.
基金support and funding from the CNPC Project(2021ZG10)National Natural Science Foundation of China(No.52174047)Sinopec Project(No.P23138).
文摘In drilling ultra-deep wells,the drilling fluid circulation usually causes erosion damage to downhole casing and drilling tools.However,the extent and process of this damage to the downhole tools is intricate and less understood.In order to systematically evaluate and clarify this damage process for different types of drilling fluid contamination,this research uses a high-temperature drilling fluid damage device to simulate the damage caused to the casing/drilling tools by various drilling fluid under a field thermal gradient.The results show that the drilling fluid residues are mainly solid-phase particles and organic components.The degree of casing/tool damage decreases with an increase in bottom hole temperature,and the casing/tool is least damaged within a temperature range of 150–180°C.Moreover,the surface of the casing/tool damaged by different types of drilling fluid shows different roughness,and the wettability of drilling fluid on the casing/tool surface increases with an increase in the degree of roughness.Oil-based drilling fluid have the strongest adhesion contamination on casing/drilling tools.In contrast,polysulfonated potassium drilling fluid and super-micro drilling fluid have the most potent erosion damage on casing/drilling tools.By analyzing the damage mechanism,it was established that the damage was mainly dominated by the abrasive wearing from solid-phase particles in concert with corrosion ions in drilling fluid,with solids producing many abrasion marks and corrosive ions causing a large number of pits.Clarifying drilling fluid's contamination and damage mechanism is significant in guiding the wellbore cleaning process and cutting associated costs.
基金supported by The National Natural Science Foundation of China(82370008,32470169)National Key R&D Program of China(2023YFC260550)Major Project of Guangzhou National Laboratory(GZNL2023A01001).
文摘Identifying the cause of respiratory tract infections is important for reducing the burden of diagnosis and treatment.To assess viral etiologies of hospitalized patients with pulmonary infection,bronchoalveolar lavage fluid(BALF)specimens were collected from non-COVID-19 adult patients(n=333,including patients with lower respiratory tract infection,tuberculosis,lung cancer,and pulmonary nodules)between November 2020 and November 2021.Multiple common respiratory pathogens were detected using multiplex reverse-transcription polymerase chain reaction.The result showed that at least one virus was identified in 35.44%(118/333)of the cases.Among these,influenza virus was the most commonly identified,followed by the parainfluenza virus,coronavirus,human rhinoviruses,and human respiratory syncytial viruses.The tuberculosis group demonstrated the highest viral detection rate,yet paradoxically exhibited the lowest co-infection rate.In contrast,the highest co-infection frequency was observed in the pulmonary nodules group.Patients with viral infections exhibited more severe clinical symptoms compared to those without detected viral infections.However,this observation was only noted in the lower respiratory tract infection group among the different disease groups.Notably,among patients infected with a specific virus,there were no significant differences in viral load between single and co-infections.Our study identified the major causative agents in hospitalized adult patients with pulmonary infection,offering insights for precise disease diagnosis and the prevention of unnecessary use of antimicrobial drugs.
基金supported by the National Natural Science Foundation of China(22308170).
文摘Temperature is a critical factor influencing the performance of coal catalytic hydrogasification in bubbling fluidized bed gasifiers.Numerical simulations at various temperatures(1023 K,1073 K,1123 K,and 1173 K)are conducted to elucidate the mechanisms by which temperature affects bubble size,global reaction performance,and particle-scale reactivity.The simulation results indicate that bubble size increases at elevated temperatures,while H_(2)-char hydrogasification reactivity is enhanced.Particle trajectory analyses reveal that particles sized between 100 and 250μm undergo intense char hydrogasification in the dense phase,contributing to the formation of hot spots.To assess the impact of temperature on the particle-scale flow-transfer-reaction process,the dimensionless quantities of Reynolds,Nusselt,and Sherwood numbers,along with the solids dispersion coefficient,are calculated.It is found that higher temperatures inhibit bubble-induced mass and heat transfer.In general,3 MPa,1123 K,and 3-4 fluidization numbers are identified as the optimal conditions for particles ranging from 0 to350μm.These findings provide valuable insights into the inherent interactions between temperature and gas-particle reaction.
基金supported by Tarim Oilfield Project“Study on Formation Characteristics and Technical Countermeasures of Drilling Fluid in Yingsha and Yulong Blocks”(Project No.201019121044)the National Natural Science Foundation of China(ZX20200280).
文摘Aiming at the leakage problem in the compact sandstone drilling of the Keziluoyi Formation in South-west Tarim,Nano-core-emulsion was prepared by coating modified nano-SiO_(2) with nano-emulsion,its particle size D50 is about 100 nm,with good dispersion stability.When 0.8%Nano-core-emulsion is added to 5%bentonite slurry,the fluid loss can be reduced by 40%,and the filter cake thickness can be reduced by 84%.Using a Nano-core-emulsion to optimize the plugging performance of potassium pol-ysulfonate drilling fluid can reduce the fluid loss of the drilling fluid by 52%,the resulting filter cake is dense and tough,and the thickness is reduced by 40%.Using the pressure conduction method to evaluate the plugging rate,the plugging rate of the drilling fluid of the Nano-core-emulsion on the core of the Keziluoyi Formation is 63.4%,which is 20.9%higher than that of the field drilling fluid.According to microscopic examination and CT scanning analysis,the material has the plugging characteristics of"inner rigid support+outer soft deformation"and has demonstrated good field application results.
基金the Australian Research Council Discovery Project(ARC DP 220100851)scheme and would acknowledge that.
文摘Particle-fluid two-phase flows in rock fractures and fracture networks play a pivotal role in determining the efficiency and effectiveness of hydraulic fracturing operations,a vital component in unconventional oil and gas extraction.Central to this phenomenon is the transport of proppants,tiny solid particles injected into the fractures to prevent them from closing once the injection is stopped.However,effective transport and deposition of proppant is critical in keeping fracture pathways open,especially in lowpermeability reservoirs.This review explores,then quantifies,the important role of fluid inertia and turbulent flows in governing proppant transport.While traditional models predominantly assume and then characterise flow as laminar,this may not accurately capture the complexities inherent in realworld hydraulic fracturing and proppant emplacement.Recent investigations highlight the paramount importance of fluid inertia,especially at the high Reynolds numbers typically associated with fracturing operations.Fluid inertia,often overlooked,introduces crucial forces that influence particle settling velocities,particle-particle interactions,and the eventual deposition of proppants within fractures.With their inherent eddies and transient and chaotic nature,turbulent flows introduce additional complexities to proppant transport,crucially altering proppant settling velocities and dispersion patterns.The following comprehensive survey of experimental,numerical,and analytical studies elucidates controls on the intricate dynamics of proppant transport under fluid inertia and turbulence-towards providing a holistic understanding of the current state-of-the-art,guiding future research directions,and optimising hydraulic fracturing practices.
基金Supported by the National Natural Science Foundation of China(U21B2062).
文摘This study comprehensively uses various methods such as production dynamic analysis,fluid inclusion thermometry and carbon-oxygen isotopic compositions testing,based on outcrop,core,well-logging,3D seismic,geochemistry experiment and production test data,to systematically explore the control mechanisms of structure and fluid on the scale,quality,effectiveness and connectivity of ultra-deep fault-controlled carbonate fractured-vuggy reservoirs in the Tarim Basin.The results show that reservoir scale is influenced by strike-slip fault scale,structural position,and mechanical stratigraphy.Larger faults tend to correspond to larger reservoir scales.The reservoir scale of contractional overlaps is larger than that of extensional overlaps,while pure strike-slip segments are small.The reservoir scale is enhanced at fault intersection,bend,and tip segments.Vertically,the heterogeneity of reservoir development is controlled by mechanical stratigraphy,with strata of higher brittleness indices being more conducive to the development of fractured-vuggy reservoirs.Multiple phases of strike-slip fault activity and fluid alterations contribute to fractured-vuggy reservoir effectiveness evolution and heterogeneity.Meteoric water activity during the Late Caledonian to Early Hercynian period was the primary phase of fractured-vuggy reservoir formation.Hydrothermal activity in the Late Hercynian period further intensified the heterogeneity of effective reservoir space distribution.The study also reveals that fractured-vuggy reservoir connectivity is influenced by strike-slip fault structural position and present in-situ stress field.The reservoir connectivity of extensional overlaps is larger than that of pure strike-slip segments,while contractional overlaps show worse reservoir connectivity.Additionally,fractured-vuggy reservoirs controlled by strike-slip faults that are nearly parallel to the present in-situ stress direction exhibit excellent connectivity.Overall,high-quality reservoirs are distributed at the fault intersection of extensional overlaps,the central zones of contractional overlaps,pinnate fault zones at intersection,bend,and tip segments of pure strike-slip segments.Vertically,they are concentrated in mechanical stratigraphy with high brittleness indices.
