It has been well recognized that sand particles significantly affect the mechanical properties of reconstituted sandy clays,including the hosted clay and sand particles.However,interrelation between the permeability a...It has been well recognized that sand particles significantly affect the mechanical properties of reconstituted sandy clays,including the hosted clay and sand particles.However,interrelation between the permeability and compressibility of reconstituted sandy clays by considering the structural effects of sand particles is still rarely reported.For this,a series of consolidation-permeability coefficient tests were conducted on reconstituted sandy clays with different sand fractions(ψ_(ss)),initial void ratio of hosted clays(e_(c0))and void ratio at liquid limit of hosted clays(e_(cL)).The roles of ψ_(ss) in both the relationships of permeability coefficient of hosted clay(k_(v-hosted clay))versus effective vertical stress(σ'_(v))and void ratio of hosted clay(e_(c-hosted clay))versus σ'_(v) were analyzed.The results show that the permeability coefficient of reconstituted sandy clays(k_(v))is dominated by hosted clay(k_(v)=k_(v-hosted clay)).Both ψ_(ss) and σ'_(v) affect the k_(v) of sandy clays by changing the e_(c-hosted clay) at any given σ'_(v).Due to the partial contacts and densified clay bridges between the sand particles(i.e.structure effects),the e_(c-hosted clay) in sandy clays is higher than that in clays at the same σ'_(v)v.The k_(v)-e_(c-hosted clay) relationship of sandy clays is independent of σ'_(v) and ψ_(ss)but is a function of e_(cL).The types of hosted clays affect the k_(v) of sandy clays by changing the e_(cL).Based on the relationship between permeability coefficient and void ratio for the reconstituted clays,an empirical method for determining the k_(v) is proposed and validated for sandy clays.The predicted values are almost consistent with the measured values with k_(v-predicted)=k_(v-measured)=0.6-2.5.展开更多
The relative permeability of oil and water is a key factor in assessing the production performance of a reservoir.This study analyzed the impact of injecting a viscosity reducer solution into low-viscosity crude oil t...The relative permeability of oil and water is a key factor in assessing the production performance of a reservoir.This study analyzed the impact of injecting a viscosity reducer solution into low-viscosity crude oil to enhance fluid flow within a low-permeability reservoir.At 72°C,the oil-water dispersion solution achieved a viscosity reduction rate(f)of 92.42%,formulated with a viscosity reducer agent concentration(C_(VR))of 0.1%and an oil-water ratio of 5:5.The interfacial tension between the viscosity reducer solution and the crude oil remained stable at approximately 1.0 mN/m across different concentrations,with the minimum value of 4.07×10^(-1)mN/m recorded at a C_(VR)of 0.2%.As the CVR increased,the relative permeability curve of the oil phase gradually decreased while the oil-water two-phase region(Ro-wtp)expanded significantly.At a C_(VR)of 0.1%,the R_(o-wtp)peaked,making an increase of 7.93 percentage points compared to water flooding.In addition,the final displacement efficiency(E_(R),final)achieved with a 0.1%viscosity reducer solution reached 48.64%,exceeding water flooding by 15.46 percentage points,highlighting the effectiveness of the viscosity reducer solution in enhancing oil recovery.展开更多
The physical properties of hydrocarbon reservoirs are important factors affecting the percolation ability of the reservoirs.Tight-sand reservoirs exhibit complex pore throat connectivity due to the extensive developme...The physical properties of hydrocarbon reservoirs are important factors affecting the percolation ability of the reservoirs.Tight-sand reservoirs exhibit complex pore throat connectivity due to the extensive development of micro-and nano-scale pore and throat systems.Characterizing the microscopic properties of these reservoirs using nondestructive,quantitative methods serves as an important means to determine the characteristics of microscopic pores and throats in tight-sand reservoirs and the mechanism behind the influence of these characteristics on reservoir porosity and permeability.In this study,a low-permeability sandstone sample and two tight sandstone samples collected from the Ordos Basin were nondestructively tested using high-resolution nano-CT technology to quantitively characterize their microscopic pore throat structures and model them three-dimensionally(in 3D)based on CT threshold differences and gray models.A thorough analysis and comparison reveal that the three samples exhibit a certain positive correlation between their porosity and permeability but the most important factor affecting both porosity and permeability is the microscopic pore throat structure.Although the number of pores in tight sandstones shows a minor impact on their porosity,large pores(more than 20μm)contribute predominantly to porosity,suggesting that the permeability of tight sandstones is controlled primarily by large pore throats.For these samples,higher permeability corresponds to larger average throat sizes.Therefore,throats with average radii greater than 2μm can significantly improve the permeability of tight sandstones.展开更多
Irregular bone scaffolds fabricated using the Voronoi tessellation method resemble the morphology and properties of human cancellous bones.This has become a prominent topic in bone tissue engineering research in recen...Irregular bone scaffolds fabricated using the Voronoi tessellation method resemble the morphology and properties of human cancellous bones.This has become a prominent topic in bone tissue engineering research in recent years.However,studies on the radial-gradient design of irregular bionic scaffolds are limited.Therefore,this study aims to develop a radial-gradient structure similar to that of natural long bones,enhancing the development of bionic bone scaffolds.A novel gradient method was adopted to maintain constant porosity,control the seed site-specific distribution within the irregular porous structure,and vary the strut diameter to generate radial gradients.The irregular scaffolds were compared with four conventional scaffolds(cube,pillar BCC,vintiles,and diamond)in terms of permeability,stress concentration characteristics,and mechanical properties.The results indicate that the radial-gradient irregular porous structure boasts the widest permeability range and superior stress distribution compared to conventional scaffolds.With an elastic modulus ranging from 4.20 GPa to 22.96 GPa and a yield strength between 68.37 MPa and 149.40 MPa,it meets bone implant performance requirements and demonstrates significant application potential.展开更多
2'-Fucosyllactose(2'-FL)shows the potential to support intestinal health as a natural prebiotic that bridges the gap between infant formula feeding and breastfeeding.However,the effect and mechanism of 2'-...2'-Fucosyllactose(2'-FL)shows the potential to support intestinal health as a natural prebiotic that bridges the gap between infant formula feeding and breastfeeding.However,the effect and mechanism of 2'-FL in improving intestinal permeability are not clear.In this study,we constructed human microbiota-associated(HMA)mouse models by colonizing healthy infant feces in mice with antibiotic-depleted intestinal microbiota.The protective effect of 2'-FL on the intestinal permeability was explored using the HMA mouse models,and the combination of metagenomics was used to analyze the possible mechanisms by which the microorganisms reduced the intestinal permeability.The results showed that 2'-FL decreased the concentration of markers of intestinal permeability(enterotoxin and diamine oxidase(DAO))and increased the expression levels of tight junctions(occludin and claudin).Metagenomics revealed the enrichment of Bifidobacterium and increased the expression of glycoside hydrolases(GHs),including GH31,GH28,and GH5.In conclusion,2'-FL strengthened intestinal permeability function by improving microbiota composition to control the translocation of harmful substance.展开更多
CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pe...CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pessimistic gas channeling.Consequently,there is a need to develop conformance control materials that can be used in CO_(2)-EOR.Herein,to address the challenges of low strength and poor stability of polymer gel in high temperature and low permeability reservoirs,a new organic/metal ion composite crosslinking polymer gel(AR-Gel)is reported,which is formed by low hydrolysis and medium to high molecular weight polymer(CX-305),organic crosslinking agent(phenolic resin),and aluminium citrate(AI(Ⅲ)).The crosslinking of AI(Ⅲ)with carboxyl group and organic/metal ion double crosslinking can construct a more complex and stable polymer gel structure on the basis of traditional chemical crosslinking,to cope with the harsh conditions such as high temperature.The structure-activity relationship of AR-Gel was revealed by rheology behavior and micro-morphology.The applicability of AR-Gel in reservoir was investigated,as was its strength and stability in supercritical CO_(2).The anti-gas channeling and enhanced oil recovery of AR-Gel were investigated using low permeability fractured cores,and the field process parameters were provided.The gel can be used to meet supercritical CO_(2)reservoirs at 110℃and 20,000 mg/L salinity,with long-term stability over 60 days.The plugging rate of AR-Gel for fractured co re was 97%,with subsequent CO_(2)flooding re sulting in an enhanced oil recovery by 34.5%.ARGel can effectively control CO_(2)gas channeling and enhanced oil recovery.It offers a new material with high strength and temperature resistance,which is particularly beneficial in the CO_(2)flooding for the conformance control of oil field.展开更多
As the first gold mine discovered at the sea in China and the only coastal gold mine currently mined there,Sanshandao Gold Mine faces unique challenges.The mine's safety is under continual threat from its faulted ...As the first gold mine discovered at the sea in China and the only coastal gold mine currently mined there,Sanshandao Gold Mine faces unique challenges.The mine's safety is under continual threat from its faulted structure coupled with the overlying water.As the mining proceeds deeper,the risk of water inrush increases.The mine's maximum water yield reaches 15000 m3/day,which is attributable to water channels present in fault zones.Predominantly composed of soil–rock mixtures(SRM),these fault zones'seepage characteristics significantly impact water inrush risk.Consequently,investigating the seepage characteristics of SRM is of paramount importance.However,the existing literature mostly concentrates on a single stress state.Therefore,this study examined the characteristics of the permeability coefficient under three distinct stress states:osmotic,osmotic–uniaxial,and osmotic–triaxial pressure.The SRM samples utilized in this study were extracted from in situ fault zones and then reshaped in the laboratory.In addition,the micromechanical properties of the SRM samples were analyzed using computed tomography scanning.The findings reveal that the permeability coefficient is the highest under osmotic pressure and lowest under osmotic–triaxial pressure.The sensitivity coefficient shows a higher value when the rock block percentage ranges between 30%and 40%,but it falls below 1.0 when this percentage exceeds 50%under no confining pressure.Notably,rock block percentages of 40%and 60%represent the two peak points of the sensitivity coefficient under osmotic–triaxial pressure.However,SRM samples with a 40%rock block percentage consistently show the lowest permeability coefficient under all stress states.This study establishes that a power function can model the relationship between the permeability coefficient and osmotic pressure,while its relationship with axial pressure can be described using an exponential function.These insights are invaluable for developing water inrush prevention and control strategies in mining environments.展开更多
The strength of the sliding zone soil determines the stability of reservoir landslides.Fluctuations in water levels cause a change in the seepage field,which serves as both the external hydrogeological environment and...The strength of the sliding zone soil determines the stability of reservoir landslides.Fluctuations in water levels cause a change in the seepage field,which serves as both the external hydrogeological environment and the internal component of a landslide.Therefore,considering the strength changes of the sliding zone with seepage effects,they correspond with the actual hydrogeological circumstances.To investigate the shear behavior of sliding zone soil under various seepage pressures,24 samples were conducted by a self-developed apparatus to observe the shear strength and measure the permeability coefficients at different deformation stages.After seepage-shear tests,the composition of clay minerals and microscopic structure on the shear surface were analyzed through X-ray and scanning electron microscope(SEM)to understand the coupling effects of seepage on strength.The results revealed that the sliding zone soil exhibited strain-hardening without seepage pressure.However,the introduction of seepage caused a significant reduction in shear strength,resulting in strain-softening characterized by a three-stage process.Long-term seepage action softened clay particles and transported broken particles into effective seepage channels,causing continuous damage to the interior structure and reducing the permeability coefficient.Increased seepage pressure decreased the peak strength by disrupting occlusal and frictional forces between sliding zone soil particles,which carried away more clay particles,contributing to an overhead structure in the soil that raised the permeability coefficient and decreased residual strength.The internal friction angle was less sensitive to variations in seepage pressure than cohesion.展开更多
Clayey-silt natural gas hydrate reservoirs in the South China Sea exhibit loose and unconsolidated structures, heterogeneous pore structures, high clay mineral contents, and strong hydrophilicity. These characteristic...Clayey-silt natural gas hydrate reservoirs in the South China Sea exhibit loose and unconsolidated structures, heterogeneous pore structures, high clay mineral contents, and strong hydrophilicity. These characteristics complicate the gas-water two-phase flow process in porous media following hydrate decomposition, posing challenges for efficient development. This study examines the transport response of clayey-silt reservoir samples from the Shenhu area using gas-water two-phase flow experiments and CT scanning to explore changes in pore structure, gas-water distribution, and relative permeability under varying flow conditions. The results indicate that pore heterogeneity significantly influences flow characteristics. Gas preferentially displaces water in larger pores, forming fracture-like pores, which serve as preferential flow channels for gas migration. The preferential flow channels enhance gas-phase permeability up to 19 times that of the water phase when fluid pressures exceed total stresses. However,small pores retain liquid, leading to a high residual water saturation of 0.561. CT imaging reveals that these hydro-fractures improve gas permeability but also confine gas flow to specific channels. Pore network analysis shows that gas injection expands the pore-throat network, enhancing connectivity and forming fracture-like pores. Residual water remains trapped in smaller pores and throats, while structural changes, including new fractures, improve gas flow pathways and overall connectivity. Relative permeability curves demonstrate a narrow gas-water cocurrent-flow zone, a right-shifted iso-permeability point and high reservoir capillary pressure, indicating a strong "water-blocking" effect. The findings suggest that optimizing reservoir stimulation techniques to enhance fracture formation, reduce residual water saturation, and improve gas flow capacity is critical for efficient hydrate reservoir development.展开更多
Understanding the storage mechanisms in CO_(2)flooding is crucial,as many carbon capture,utilization,and storage(CCUS)projects are related to enhanced oil recovery(EOR).CO_(2)storage in reservoirs across large timesca...Understanding the storage mechanisms in CO_(2)flooding is crucial,as many carbon capture,utilization,and storage(CCUS)projects are related to enhanced oil recovery(EOR).CO_(2)storage in reservoirs across large timescales undergoes the two storage stages of oil displacement and well shut-in,which cover mul-tiple replacement processes of injection-production synchronization,injection only with no production,and injection-production stoppage.Because the controlling mechanism of CO_(2)storage in different stages is unknown,the evolution of CO_(2)storage mechanisms over large timescales is not understood.A math-ematical model for the evaluation of CO_(2)storage,including stratigraphic,residual,solubility,and mineral trapping in low-permeability tight sandstone reservoirs,was established using experimental and theoret-ical analyses.Based on a detailed geological model of the Huaziping Oilfield,calibrated with reservoir permeability and fracture characteristic parameters obtained from well test results,a dynamic simulation of CO_(2)storage for the entire reservoir life cycle under two scenarios of continuous injection and water-gas alternation were considered.The results show that CO_(2)storage exhibits the significant stage charac-teristics of complete storage,dynamic storage,and stable storage.The CO_(2)storage capacity and storage rate under the continuous gas injection scenario(scenario 1)were 6.34×10^(4)t and 61%,while those under the water-gas alternation scenario(scenario 2)were 4.62×10^(4)t and 46%.The proportions of stor-age capacity under scenarios 1 and 2 for structural or stratigraphic,residual,solubility,and mineral trap-ping were 33.36%,33.96%,32.43%,and 0.25%;and 15.09%,38.65%,45.77%,and 0.49%,respectively.The evolution of the CO_(2)storage mechanism showed an overall trend:stratigraphic and residual trapping first increased and then decreased,whereas solubility trapping gradually decreased,and mineral trapping continuously increased.Based on these results,an evolution diagram of the CO_(2)storage mechanism of low-permeability tight sandstone reservoirs across large timescales was established.展开更多
In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability o...In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability of the fracture.To evaluate this relationship,we numerically generated self-affine fractures reproducing the scaling relationship of the power spectral density(PSD)of the measured fracture surfaces.The fractures were then subjected to a uniform and stepwise increase in normal stress.A fast Fourier transform(FFT)-based elastic contact model was used to simulate the fracture closure.The evolution of fracture contact area,fracture closure,and fracture normal stiffness were determined throughout the whole process.In addition,the fracture permeability at each step was calculated by the local cubic law(LCL).The influences of roughness exponent and correlation length on the fracture hydraulic and mechanical behaviors were investigated.Based on the power law of normal stiffness versus normal stress,the corrected cubic law and the linear relationship between fracture closure and mechanical aperture were obtained from numerical modeling of a set of fractures.Then,we derived a fracture normal stiffness-permeability equation which incorporates fracture geometric parameters such as the root-mean-square(RMS),roughness exponent,and correlation length,which can describe the fracture flow under an effective medium regime and a percolation regime.Finally,we interpreted the flow transition behavior from the effective medium regime to the percolation regime during fracture closure with the established stiffness-permeability function.展开更多
In view of the increased focus on“green”and sustainable development and compliance with the national strategy for“carbon peak and carbon neutrality,”this study investigated the effect of replacing cement(0-20%)wit...In view of the increased focus on“green”and sustainable development and compliance with the national strategy for“carbon peak and carbon neutrality,”this study investigated the effect of replacing cement(0-20%)with limestone powder(stone powder)as a mineral admixture on the micro,meso,and macro properties of mortar.First,the applicability of stone powder was examined based on the physical filling and heat of hydration of stone powder-cement.Second,micro-meso testing methods,such as X-ray diffraction,scanning electron microscopy,thermogravimetry-differential scanning calorimetry,and nuclear magnetic resonance,were utilized to reveal the influencing mechanisms of stone powder on the microstructure of the mortar.Furthermore,the effect of stone powder on the compressive strength and gas permeability of the mortar was analyzed.Additionally,the time-dependent variations in the gas permeability and its functional relationship with the mechanical properties were determined.Finally,the correlation between the compressive strength and gas permeability with respect to the pore size of stone powder-doped mortar was established via gray-correlation analysis.The results show that an appropriate amount of stone powder(5%)can effectively improve the particle gradation,decelerate the release of the heat of hydration,increase the amount of hydration products,and improve the pore structure,thereby increasing the compressive strength and reducing the gas permeability coefficient.The gas permeability of stone powder-doped mortar was found to exhibit good time-dependent characteristics as well as a quadratic linear correlation with the compressive strength.The gray-correlation analysis results indicate that air pores exhibit the highest influence on the compressive strength and that the gas permeability coefficient is most significantly affected by large pores.展开更多
BACKGROUND Although an association between gut microbiota and cholestatic liver disease(CLD)has been reported,the precise functional roles of these microbes in CLD pathogenesis remain largely unknown.AIM To explore th...BACKGROUND Although an association between gut microbiota and cholestatic liver disease(CLD)has been reported,the precise functional roles of these microbes in CLD pathogenesis remain largely unknown.AIM To explore the function of gut microbes in CLD pathogenesis and the effects of gut microbiota on intestinal barrier and bile acid(BA)metabolism in CLD.METHODS Male C57BL/6J mice were fed a 0.05%3,5-diethoxycarbonyl-1,4-dihydrocollidine diet for 2 weeks to induce CLD.The sterile liver tissues of mice were then meticulously harvested,and bacteria in homogenates were identified through culture methods.Furthermore,16S ribosomal DNA sequencing was employed to analyze sterile liver samples collected from eight patients with primary biliary cholangitis(PBC)and three control individuals with hepatic cysts.The functional roles of the identified bacteria in CLD pathogenesis were assessed through microbiota transfer experiments,involving the evaluation of changes in intestinal permeability and BA dynamics.RESULTS Ligilactobacillus murinus(L.murinus)and Lactococcus garvieae(L.garvieae)were isolated from the bacterial culture of livers from CLD mice.L.murinus was prevalently detected in PBC patients and controls,whereas L.garvieae was detected only in patients with PBC but not in controls.Mice inoculated with L.garvieae exhibited increased susceptibility to experimental CLD,with both in vitro and in vivo indicating that L.garvieae disrupted the intestinal barrier function by down-regulating the expression of occludin and zonula occludens-1.Moreover,L.garvieae administration significantly upregulated the expression of the apical sodium-dependent BA transporter in the terminal ileum and increased serum BA levels.CONCLUSION L.garvieae contributes to excessive BA-induced hepatobiliary injury and liver fibrosis by increasing intestinal permeability and enhancing BA reabsorption.展开更多
Reliable forecasting of coal seam gas production and gas injectivity(e.g.,CO_(2) or air)requires an accurate understanding of coal’s anisotropic permeability,which governs the directional flow of gas.Although the ani...Reliable forecasting of coal seam gas production and gas injectivity(e.g.,CO_(2) or air)requires an accurate understanding of coal’s anisotropic permeability,which governs the directional flow of gas.Although the anisotropic nature of coal permeability is well recognized,little attention has been paid to how this ratio evolves with changes in effective stress or with the injection of gases that have different affinities to coal.In this work,more than 600 permeability tests were conducted on eight cubic Australian coal samples using He,N_(2) and CO_(2) gases under varying effective stresses,providing a comprehensive dataset that allows the combined effects of effective stress and gas adsorption on permeability anisotropy to be robustly assessed on the same samples.The results demonstrated that all coal samples exhibited evident permeability anisotropy,with ratios ranging from 1.11 to 6.55.For the first time,quantitative relationships between the anisotropy ratio,effective stress,and initial permeability were established for each of the three injection gases,highlighting how gas adsorption and effective stress changes both anisotropic permeability magnitude and ratio.These findings provide new insights into the directional flow behavior of gases in coal seams,with implications for underground compressed air energy storage and CO_(2) sequestration.展开更多
During gas extraction from deep coal,the rock endures high effective stress,with both the time-dependent deformation and anisotropic structure of the rock controlling the permeability evolution.To reveal this phenomen...During gas extraction from deep coal,the rock endures high effective stress,with both the time-dependent deformation and anisotropic structure of the rock controlling the permeability evolution.To reveal this phenomenon,a numerical simulation framework of the finite volume method and transient embedded discrete fracture model is proposed to establish a new constitutive model that links poroelastoplastic deformation,adsorption-induced swelling,and aperture compression.From this model,anisotropic permeability tensors were derived to further achieve the simulation of coevolution.Meanwhile,our permeability model was verified against the measured permeability data,and the history match of the numerical model showed better results where the mismatch was less than 5%.The results indicate that(1)the long-term permeability evolution clearly showed the competitive effects of multiple deformation mechanisms,which involves three stages:compaction-dominated decline,adsorption-dominated rebound,and creep-controlled loss.(2)The increased number of compressible cleats/fractures accelerated the initial permeability decline,while the increased desorption-induced strain promoted faster rebound and enhancement and higher viscosity coefficients enhanced the creep effect,which led to significant long-term permeability loss.(3)Massive hydraulic fracturing created a larger drainage area,accelerating methane desorption and causing sharp permeability rebound with reduced residual gas,which shows that the permeability remained higher than the initial values even after the extensive extraction via the fractured horizontal wells.The permeability evolution mechanisms displayed varying properties,such as coal rank and burial depth,and distinct characteristics.A precise understanding of multiple competitive stress effects is crucial for optimizing coalbed methane extraction techniques and improving recovery efficiency.展开更多
Permeability is one of the main oil reservoir characteristics.It affects potential oil production,well-completion technologies,the choice of enhanced oil recovery methods,and more.The methods used to determine and pre...Permeability is one of the main oil reservoir characteristics.It affects potential oil production,well-completion technologies,the choice of enhanced oil recovery methods,and more.The methods used to determine and predict reservoir permeability have serious shortcomings.This article aims to refine and adapt machine learning techniques using historical data from hydrocarbon field development to evaluate and predict parameters such as the skin factor and permeability of the remote reservoir zone.The article analyzes data from 4045 wells tests in oil fields in the Perm Krai(Russia).An evaluation of the performance of different Machine Learning(ML)al-gorithms in the prediction of the well permeability is performed.Three different real datasets are used to train more than 20 machine learning regressors,whose hyperparameters are optimized using Bayesian Optimization(BO).The resulting models demonstrate significantly better predictive performance compared to traditional methods and the best ML model found is one that never was applied before to this problem.The permeability prediction model is characterized by a high R^(2) adjusted value of 0.799.A promising approach is the integration of machine learning methods and the use of pressure recovery curves to estimate permeability in real-time.The work is unique for its approach to predicting pressure recovery curves during well operation without stopping wells,providing primary data for interpretation.These innovations are exclusive and can improve the accuracy of permeability forecasts.It also reduces well downtime associated with traditional well-testing procedures.The proposed methods pave the way for more efficient and cost-effective reservoir development,ultimately sup-porting better decision-making and resource optimization in oil production.展开更多
Based on the waterflooding development in carbonate reservoirs in the Middle East,this study analyzes the geological characteristics and waterflooding behaviors/patterns of different types of high permeability zones(H...Based on the waterflooding development in carbonate reservoirs in the Middle East,this study analyzes the geological characteristics and waterflooding behaviors/patterns of different types of high permeability zones(HPZs),and proposes rational waterflooding strategies and modes.Four types of HPZs,i.e.sedimentation-dominated,sedimentation-diagenesis coupling,biogenic and composite,are identified in the carbonate reservoirs in the Middle East.Based on their distribution patterns,flow mechanisms,and waterflooding behaviors/patterns,five waterflooding modes are established:(1)the mode with stepwise-infilled areal vertical well pattern,for composite HFZs in patchy distribution;(2)the mode with regular row vertical well pattern for TypeⅠchannel“network”HFZs(with dominant water flow pathways at the base),and the mode with irregular differentiated vertical well pattern for TypeⅡchannel“network”HFZs(where multi-stage superimposition leads to“layered flooding”),for sedimentation-diagenesis coupling HFZs;(3)the mode with row horizontal wells through bottom injection and top production,for biogenic HFZs characterized by thin,contiguous distribution and rapid advancing of injected water along a工-shaped path;and(4)the mode with progressive waterflooding through edge water injection via vertical well and oil production via horizontal well,for sedimentation-dominated HFZs characterized by thick,contiguous distribution and flood first in upper anti-rhythmic reservoirs.Development practices demonstrate that the proposed waterflooding modes are efficient in the highly heterogeneous carbonate reservoirs in the Middle East,with balanced employment of reserves in the adjacent reservoirs and enhanced oil recovery.展开更多
Carbonates present complex pore systems that strongly influence the physical properties and their interrelationships.This study proposes a new approach to establish pore-type mixing-based permeability transforms by in...Carbonates present complex pore systems that strongly influence the physical properties and their interrelationships.This study proposes a new approach to establish pore-type mixing-based permeability transforms by integrating well-log and core data.We investigate the influence of pore-structure heterogeneity on permeability and velocity through the rock-frame flexibility factors(γ and γ_(μ)),derivable using standard sonic and density logs.We derive permeability transforms,with correlation coefficients,R of 0.8 to 0.9,from core measurements and pore-structure variations-dependent physical parameters,namely the porosity exponent(m),Poisson’s ratio(σ),velocity deviation log(VDL),and velocity ratio(VR).Through extrapolation using log-data,the m-and VDL-based correlations provide significantly better permeability estimates,with the highest accuracy attained with the m-based correlation,whereas the VR-andσ-based correlations lead to permeability overes-timation for high porosities.We plotted log-derived porosity vs.permeability,obtained applying the m-based correlation,to generate consistent porosity-permeability relationships,which account for pore-structure heterogeneity,by sorting the scattering points into distinct groups/trends by considering the variations of pore-structure types and abundance of a specific porosity.For the studied oilfield,three porosity-permeability relationships are identified,with correlation coefficients approaching 0.9,thus validating the approach and supporting its application in petrophysically similar reservoirs.展开更多
In this study,a series of triaxial tests are conducted on sandstone specimens to investigate the evolution of their mechanics and permeability characteristics under the combined action of immersion corrosion and seepa...In this study,a series of triaxial tests are conducted on sandstone specimens to investigate the evolution of their mechanics and permeability characteristics under the combined action of immersion corrosion and seepage of different chemical solutions.It is observed that with the increase of confining pressure,the peak stress,dilatancy stress,dilatancy stress ratio,peak strain,and elastic modulus of the sandstone increase while the Poisson ratio decreases and less secondary cracks are produced when the samples are broken.The pore pressure and confining pressure have opposite influences on the mechanical properties.With the increase of the applied axial stress,three stages are clearly identified in the permeability evolution curves:initial compaction stage,linear elasticity stage and plastic deformation stage.The permeability reaches the maximum value when the highest volumetric dilatancy is obtained.In addition,the hydrochemical action of salt solution with pH=7 and 4 has an obvious deteriorating effect on the mechanical properties and induces the increase of permeability.The obtained results will be useful in engineering to understand the mechanical and seepage properties of sandstone under the coupled chemical-seepage-stress multiple fields.展开更多
Kirsten rat sarcoma viral oncogene homolog(KRAS)protein inhibitors are a promising class of therapeutics,but research on molecules that effectively penetrate the blood-brain barrier(BBB)remains limited,which is crucia...Kirsten rat sarcoma viral oncogene homolog(KRAS)protein inhibitors are a promising class of therapeutics,but research on molecules that effectively penetrate the blood-brain barrier(BBB)remains limited,which is crucial for treating central nervous system(CNS)malignancies.Although molecular generation models have recently advanced drug discovery,they often overlook the complexity of biological and chemical factors,leaving room for improvement.In this study,we present a structureconstrained molecular generation workflow designed to optimize lead compounds for both drug efficacy and drug absorption properties.Our approach utilizes a variational autoencoder(VAE)generative model integrated with reinforcement learning for multi-objective optimization.This method specifically aims to enhance BBB permeability(BBBp)while maintaining high-affinity substructures of KRAS inhibitors.To support this,we incorporate a specialized KRAS BBB predictor based on active learning and an affinity predictor employing comparative learning models.Additionally,we introduce two novel metrics,the knowledge-integrated reproduction score(KIRS)and the composite diversity score(CDS),to assess structural performance and biological relevance.Retrospective validation with KRAS inhibitors,AMG510 and MRTX849,demonstrates the framework’s effectiveness in optimizing BBBp and highlights its potential for real-world drug development applications.This study provides a robust framework for accelerating the structural enhancement of lead compounds,advancing the drug development process across diverse targets.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.52278334 and 4197724)Fundamental Research Funds for the Central Universities (Grant No.2242024k30066).
文摘It has been well recognized that sand particles significantly affect the mechanical properties of reconstituted sandy clays,including the hosted clay and sand particles.However,interrelation between the permeability and compressibility of reconstituted sandy clays by considering the structural effects of sand particles is still rarely reported.For this,a series of consolidation-permeability coefficient tests were conducted on reconstituted sandy clays with different sand fractions(ψ_(ss)),initial void ratio of hosted clays(e_(c0))and void ratio at liquid limit of hosted clays(e_(cL)).The roles of ψ_(ss) in both the relationships of permeability coefficient of hosted clay(k_(v-hosted clay))versus effective vertical stress(σ'_(v))and void ratio of hosted clay(e_(c-hosted clay))versus σ'_(v) were analyzed.The results show that the permeability coefficient of reconstituted sandy clays(k_(v))is dominated by hosted clay(k_(v)=k_(v-hosted clay)).Both ψ_(ss) and σ'_(v) affect the k_(v) of sandy clays by changing the e_(c-hosted clay) at any given σ'_(v).Due to the partial contacts and densified clay bridges between the sand particles(i.e.structure effects),the e_(c-hosted clay) in sandy clays is higher than that in clays at the same σ'_(v)v.The k_(v)-e_(c-hosted clay) relationship of sandy clays is independent of σ'_(v) and ψ_(ss)but is a function of e_(cL).The types of hosted clays affect the k_(v) of sandy clays by changing the e_(cL).Based on the relationship between permeability coefficient and void ratio for the reconstituted clays,an empirical method for determining the k_(v) is proposed and validated for sandy clays.The predicted values are almost consistent with the measured values with k_(v-predicted)=k_(v-measured)=0.6-2.5.
基金supported by the Petrochina Daqing Oilfield Research Project(No.DQYT-1201002-2023-JS-1201).
文摘The relative permeability of oil and water is a key factor in assessing the production performance of a reservoir.This study analyzed the impact of injecting a viscosity reducer solution into low-viscosity crude oil to enhance fluid flow within a low-permeability reservoir.At 72°C,the oil-water dispersion solution achieved a viscosity reduction rate(f)of 92.42%,formulated with a viscosity reducer agent concentration(C_(VR))of 0.1%and an oil-water ratio of 5:5.The interfacial tension between the viscosity reducer solution and the crude oil remained stable at approximately 1.0 mN/m across different concentrations,with the minimum value of 4.07×10^(-1)mN/m recorded at a C_(VR)of 0.2%.As the CVR increased,the relative permeability curve of the oil phase gradually decreased while the oil-water two-phase region(Ro-wtp)expanded significantly.At a C_(VR)of 0.1%,the R_(o-wtp)peaked,making an increase of 7.93 percentage points compared to water flooding.In addition,the final displacement efficiency(E_(R),final)achieved with a 0.1%viscosity reducer solution reached 48.64%,exceeding water flooding by 15.46 percentage points,highlighting the effectiveness of the viscosity reducer solution in enhancing oil recovery.
文摘The physical properties of hydrocarbon reservoirs are important factors affecting the percolation ability of the reservoirs.Tight-sand reservoirs exhibit complex pore throat connectivity due to the extensive development of micro-and nano-scale pore and throat systems.Characterizing the microscopic properties of these reservoirs using nondestructive,quantitative methods serves as an important means to determine the characteristics of microscopic pores and throats in tight-sand reservoirs and the mechanism behind the influence of these characteristics on reservoir porosity and permeability.In this study,a low-permeability sandstone sample and two tight sandstone samples collected from the Ordos Basin were nondestructively tested using high-resolution nano-CT technology to quantitively characterize their microscopic pore throat structures and model them three-dimensionally(in 3D)based on CT threshold differences and gray models.A thorough analysis and comparison reveal that the three samples exhibit a certain positive correlation between their porosity and permeability but the most important factor affecting both porosity and permeability is the microscopic pore throat structure.Although the number of pores in tight sandstones shows a minor impact on their porosity,large pores(more than 20μm)contribute predominantly to porosity,suggesting that the permeability of tight sandstones is controlled primarily by large pore throats.For these samples,higher permeability corresponds to larger average throat sizes.Therefore,throats with average radii greater than 2μm can significantly improve the permeability of tight sandstones.
基金the National Natural Science Foundation of China(No.52165026)。
文摘Irregular bone scaffolds fabricated using the Voronoi tessellation method resemble the morphology and properties of human cancellous bones.This has become a prominent topic in bone tissue engineering research in recent years.However,studies on the radial-gradient design of irregular bionic scaffolds are limited.Therefore,this study aims to develop a radial-gradient structure similar to that of natural long bones,enhancing the development of bionic bone scaffolds.A novel gradient method was adopted to maintain constant porosity,control the seed site-specific distribution within the irregular porous structure,and vary the strut diameter to generate radial gradients.The irregular scaffolds were compared with four conventional scaffolds(cube,pillar BCC,vintiles,and diamond)in terms of permeability,stress concentration characteristics,and mechanical properties.The results indicate that the radial-gradient irregular porous structure boasts the widest permeability range and superior stress distribution compared to conventional scaffolds.With an elastic modulus ranging from 4.20 GPa to 22.96 GPa and a yield strength between 68.37 MPa and 149.40 MPa,it meets bone implant performance requirements and demonstrates significant application potential.
基金financially supported by the National Key Research and Development Program of China(2022YFF1100402)National Center of Technology Innovation for Dairy(2022-Open subject-11)+1 种基金Young Elite Scientist Sponsorship Program by CAST(YESS20200271)the National Natural Science Foundation of China(32101919)。
文摘2'-Fucosyllactose(2'-FL)shows the potential to support intestinal health as a natural prebiotic that bridges the gap between infant formula feeding and breastfeeding.However,the effect and mechanism of 2'-FL in improving intestinal permeability are not clear.In this study,we constructed human microbiota-associated(HMA)mouse models by colonizing healthy infant feces in mice with antibiotic-depleted intestinal microbiota.The protective effect of 2'-FL on the intestinal permeability was explored using the HMA mouse models,and the combination of metagenomics was used to analyze the possible mechanisms by which the microorganisms reduced the intestinal permeability.The results showed that 2'-FL decreased the concentration of markers of intestinal permeability(enterotoxin and diamine oxidase(DAO))and increased the expression levels of tight junctions(occludin and claudin).Metagenomics revealed the enrichment of Bifidobacterium and increased the expression of glycoside hydrolases(GHs),including GH31,GH28,and GH5.In conclusion,2'-FL strengthened intestinal permeability function by improving microbiota composition to control the translocation of harmful substance.
基金project was supported by the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China)(No.SKLDOG2024-ZYRC-06)Key Program of National Natural Science Foundation of China(52130401)+1 种基金National Natural Science Foundation of China(52104055,52374058)Shandong Provincial Natural Science Foundation,China(ZR2021ME171,ZR2024YQ043)。
文摘CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pessimistic gas channeling.Consequently,there is a need to develop conformance control materials that can be used in CO_(2)-EOR.Herein,to address the challenges of low strength and poor stability of polymer gel in high temperature and low permeability reservoirs,a new organic/metal ion composite crosslinking polymer gel(AR-Gel)is reported,which is formed by low hydrolysis and medium to high molecular weight polymer(CX-305),organic crosslinking agent(phenolic resin),and aluminium citrate(AI(Ⅲ)).The crosslinking of AI(Ⅲ)with carboxyl group and organic/metal ion double crosslinking can construct a more complex and stable polymer gel structure on the basis of traditional chemical crosslinking,to cope with the harsh conditions such as high temperature.The structure-activity relationship of AR-Gel was revealed by rheology behavior and micro-morphology.The applicability of AR-Gel in reservoir was investigated,as was its strength and stability in supercritical CO_(2).The anti-gas channeling and enhanced oil recovery of AR-Gel were investigated using low permeability fractured cores,and the field process parameters were provided.The gel can be used to meet supercritical CO_(2)reservoirs at 110℃and 20,000 mg/L salinity,with long-term stability over 60 days.The plugging rate of AR-Gel for fractured co re was 97%,with subsequent CO_(2)flooding re sulting in an enhanced oil recovery by 34.5%.ARGel can effectively control CO_(2)gas channeling and enhanced oil recovery.It offers a new material with high strength and temperature resistance,which is particularly beneficial in the CO_(2)flooding for the conformance control of oil field.
基金State Key Research Development Program of China,Grant/Award Number:2021YFC3001301。
文摘As the first gold mine discovered at the sea in China and the only coastal gold mine currently mined there,Sanshandao Gold Mine faces unique challenges.The mine's safety is under continual threat from its faulted structure coupled with the overlying water.As the mining proceeds deeper,the risk of water inrush increases.The mine's maximum water yield reaches 15000 m3/day,which is attributable to water channels present in fault zones.Predominantly composed of soil–rock mixtures(SRM),these fault zones'seepage characteristics significantly impact water inrush risk.Consequently,investigating the seepage characteristics of SRM is of paramount importance.However,the existing literature mostly concentrates on a single stress state.Therefore,this study examined the characteristics of the permeability coefficient under three distinct stress states:osmotic,osmotic–uniaxial,and osmotic–triaxial pressure.The SRM samples utilized in this study were extracted from in situ fault zones and then reshaped in the laboratory.In addition,the micromechanical properties of the SRM samples were analyzed using computed tomography scanning.The findings reveal that the permeability coefficient is the highest under osmotic pressure and lowest under osmotic–triaxial pressure.The sensitivity coefficient shows a higher value when the rock block percentage ranges between 30%and 40%,but it falls below 1.0 when this percentage exceeds 50%under no confining pressure.Notably,rock block percentages of 40%and 60%represent the two peak points of the sensitivity coefficient under osmotic–triaxial pressure.However,SRM samples with a 40%rock block percentage consistently show the lowest permeability coefficient under all stress states.This study establishes that a power function can model the relationship between the permeability coefficient and osmotic pressure,while its relationship with axial pressure can be described using an exponential function.These insights are invaluable for developing water inrush prevention and control strategies in mining environments.
基金supported by the Major Program of the National Natural Science Foundation of China (Grant No.42090055)the National Major Scientific Instruments and Equipment Development Projects of China (Grant No.41827808)the National Nature Science Foundation of China (Grant No.42207216).
文摘The strength of the sliding zone soil determines the stability of reservoir landslides.Fluctuations in water levels cause a change in the seepage field,which serves as both the external hydrogeological environment and the internal component of a landslide.Therefore,considering the strength changes of the sliding zone with seepage effects,they correspond with the actual hydrogeological circumstances.To investigate the shear behavior of sliding zone soil under various seepage pressures,24 samples were conducted by a self-developed apparatus to observe the shear strength and measure the permeability coefficients at different deformation stages.After seepage-shear tests,the composition of clay minerals and microscopic structure on the shear surface were analyzed through X-ray and scanning electron microscope(SEM)to understand the coupling effects of seepage on strength.The results revealed that the sliding zone soil exhibited strain-hardening without seepage pressure.However,the introduction of seepage caused a significant reduction in shear strength,resulting in strain-softening characterized by a three-stage process.Long-term seepage action softened clay particles and transported broken particles into effective seepage channels,causing continuous damage to the interior structure and reducing the permeability coefficient.Increased seepage pressure decreased the peak strength by disrupting occlusal and frictional forces between sliding zone soil particles,which carried away more clay particles,contributing to an overhead structure in the soil that raised the permeability coefficient and decreased residual strength.The internal friction angle was less sensitive to variations in seepage pressure than cohesion.
基金the National Natural Science Foundation of China (Nos. 42302143, 42172159)China Geological Survey Project (No. DD20211350)support from the G. Albert Shoemaker endowment
文摘Clayey-silt natural gas hydrate reservoirs in the South China Sea exhibit loose and unconsolidated structures, heterogeneous pore structures, high clay mineral contents, and strong hydrophilicity. These characteristics complicate the gas-water two-phase flow process in porous media following hydrate decomposition, posing challenges for efficient development. This study examines the transport response of clayey-silt reservoir samples from the Shenhu area using gas-water two-phase flow experiments and CT scanning to explore changes in pore structure, gas-water distribution, and relative permeability under varying flow conditions. The results indicate that pore heterogeneity significantly influences flow characteristics. Gas preferentially displaces water in larger pores, forming fracture-like pores, which serve as preferential flow channels for gas migration. The preferential flow channels enhance gas-phase permeability up to 19 times that of the water phase when fluid pressures exceed total stresses. However,small pores retain liquid, leading to a high residual water saturation of 0.561. CT imaging reveals that these hydro-fractures improve gas permeability but also confine gas flow to specific channels. Pore network analysis shows that gas injection expands the pore-throat network, enhancing connectivity and forming fracture-like pores. Residual water remains trapped in smaller pores and throats, while structural changes, including new fractures, improve gas flow pathways and overall connectivity. Relative permeability curves demonstrate a narrow gas-water cocurrent-flow zone, a right-shifted iso-permeability point and high reservoir capillary pressure, indicating a strong "water-blocking" effect. The findings suggest that optimizing reservoir stimulation techniques to enhance fracture formation, reduce residual water saturation, and improve gas flow capacity is critical for efficient hydrate reservoir development.
基金supported by the National Key Research and Development Program of China(2022YFE0206700).
文摘Understanding the storage mechanisms in CO_(2)flooding is crucial,as many carbon capture,utilization,and storage(CCUS)projects are related to enhanced oil recovery(EOR).CO_(2)storage in reservoirs across large timescales undergoes the two storage stages of oil displacement and well shut-in,which cover mul-tiple replacement processes of injection-production synchronization,injection only with no production,and injection-production stoppage.Because the controlling mechanism of CO_(2)storage in different stages is unknown,the evolution of CO_(2)storage mechanisms over large timescales is not understood.A math-ematical model for the evaluation of CO_(2)storage,including stratigraphic,residual,solubility,and mineral trapping in low-permeability tight sandstone reservoirs,was established using experimental and theoret-ical analyses.Based on a detailed geological model of the Huaziping Oilfield,calibrated with reservoir permeability and fracture characteristic parameters obtained from well test results,a dynamic simulation of CO_(2)storage for the entire reservoir life cycle under two scenarios of continuous injection and water-gas alternation were considered.The results show that CO_(2)storage exhibits the significant stage charac-teristics of complete storage,dynamic storage,and stable storage.The CO_(2)storage capacity and storage rate under the continuous gas injection scenario(scenario 1)were 6.34×10^(4)t and 61%,while those under the water-gas alternation scenario(scenario 2)were 4.62×10^(4)t and 46%.The proportions of stor-age capacity under scenarios 1 and 2 for structural or stratigraphic,residual,solubility,and mineral trap-ping were 33.36%,33.96%,32.43%,and 0.25%;and 15.09%,38.65%,45.77%,and 0.49%,respectively.The evolution of the CO_(2)storage mechanism showed an overall trend:stratigraphic and residual trapping first increased and then decreased,whereas solubility trapping gradually decreased,and mineral trapping continuously increased.Based on these results,an evolution diagram of the CO_(2)storage mechanism of low-permeability tight sandstone reservoirs across large timescales was established.
基金supported by the China Postdoctoral Science Foundation Funded Project(Grant No.2023M740385)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233326)the support by the Helmholtz Association's Initiative and Networking Fund for the Helmholtz Young Investigator Group ARES(Contract No.VH-NG-1516).
文摘In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability of the fracture.To evaluate this relationship,we numerically generated self-affine fractures reproducing the scaling relationship of the power spectral density(PSD)of the measured fracture surfaces.The fractures were then subjected to a uniform and stepwise increase in normal stress.A fast Fourier transform(FFT)-based elastic contact model was used to simulate the fracture closure.The evolution of fracture contact area,fracture closure,and fracture normal stiffness were determined throughout the whole process.In addition,the fracture permeability at each step was calculated by the local cubic law(LCL).The influences of roughness exponent and correlation length on the fracture hydraulic and mechanical behaviors were investigated.Based on the power law of normal stiffness versus normal stress,the corrected cubic law and the linear relationship between fracture closure and mechanical aperture were obtained from numerical modeling of a set of fractures.Then,we derived a fracture normal stiffness-permeability equation which incorporates fracture geometric parameters such as the root-mean-square(RMS),roughness exponent,and correlation length,which can describe the fracture flow under an effective medium regime and a percolation regime.Finally,we interpreted the flow transition behavior from the effective medium regime to the percolation regime during fracture closure with the established stiffness-permeability function.
基金Funded by the National Natural Science Foundation of China project(Nos.52108219 and U21A20150)the Lanzhou University of Technology Hongliu Outstanding Young Talent Program,China(No.04-062407)the Research on Quality Control Technology of High-performance Concrete Prepared by Manufactured Sand(No.2020Y21)。
文摘In view of the increased focus on“green”and sustainable development and compliance with the national strategy for“carbon peak and carbon neutrality,”this study investigated the effect of replacing cement(0-20%)with limestone powder(stone powder)as a mineral admixture on the micro,meso,and macro properties of mortar.First,the applicability of stone powder was examined based on the physical filling and heat of hydration of stone powder-cement.Second,micro-meso testing methods,such as X-ray diffraction,scanning electron microscopy,thermogravimetry-differential scanning calorimetry,and nuclear magnetic resonance,were utilized to reveal the influencing mechanisms of stone powder on the microstructure of the mortar.Furthermore,the effect of stone powder on the compressive strength and gas permeability of the mortar was analyzed.Additionally,the time-dependent variations in the gas permeability and its functional relationship with the mechanical properties were determined.Finally,the correlation between the compressive strength and gas permeability with respect to the pore size of stone powder-doped mortar was established via gray-correlation analysis.The results show that an appropriate amount of stone powder(5%)can effectively improve the particle gradation,decelerate the release of the heat of hydration,increase the amount of hydration products,and improve the pore structure,thereby increasing the compressive strength and reducing the gas permeability coefficient.The gas permeability of stone powder-doped mortar was found to exhibit good time-dependent characteristics as well as a quadratic linear correlation with the compressive strength.The gray-correlation analysis results indicate that air pores exhibit the highest influence on the compressive strength and that the gas permeability coefficient is most significantly affected by large pores.
基金Supported by Tianjin Health Research Project,No.TJWJ2024QN005Beijing iGandan Public Welfare Foundation Artificial Liver Special Fund,No.iGandanF-1082024-RGG122.
文摘BACKGROUND Although an association between gut microbiota and cholestatic liver disease(CLD)has been reported,the precise functional roles of these microbes in CLD pathogenesis remain largely unknown.AIM To explore the function of gut microbes in CLD pathogenesis and the effects of gut microbiota on intestinal barrier and bile acid(BA)metabolism in CLD.METHODS Male C57BL/6J mice were fed a 0.05%3,5-diethoxycarbonyl-1,4-dihydrocollidine diet for 2 weeks to induce CLD.The sterile liver tissues of mice were then meticulously harvested,and bacteria in homogenates were identified through culture methods.Furthermore,16S ribosomal DNA sequencing was employed to analyze sterile liver samples collected from eight patients with primary biliary cholangitis(PBC)and three control individuals with hepatic cysts.The functional roles of the identified bacteria in CLD pathogenesis were assessed through microbiota transfer experiments,involving the evaluation of changes in intestinal permeability and BA dynamics.RESULTS Ligilactobacillus murinus(L.murinus)and Lactococcus garvieae(L.garvieae)were isolated from the bacterial culture of livers from CLD mice.L.murinus was prevalently detected in PBC patients and controls,whereas L.garvieae was detected only in patients with PBC but not in controls.Mice inoculated with L.garvieae exhibited increased susceptibility to experimental CLD,with both in vitro and in vivo indicating that L.garvieae disrupted the intestinal barrier function by down-regulating the expression of occludin and zonula occludens-1.Moreover,L.garvieae administration significantly upregulated the expression of the apical sodium-dependent BA transporter in the terminal ileum and increased serum BA levels.CONCLUSION L.garvieae contributes to excessive BA-induced hepatobiliary injury and liver fibrosis by increasing intestinal permeability and enhancing BA reabsorption.
基金funded by industry members APLNG,Arrow Energy,and Santos through The Gas and Energy Transition Research Centre in The University of Queensland.
文摘Reliable forecasting of coal seam gas production and gas injectivity(e.g.,CO_(2) or air)requires an accurate understanding of coal’s anisotropic permeability,which governs the directional flow of gas.Although the anisotropic nature of coal permeability is well recognized,little attention has been paid to how this ratio evolves with changes in effective stress or with the injection of gases that have different affinities to coal.In this work,more than 600 permeability tests were conducted on eight cubic Australian coal samples using He,N_(2) and CO_(2) gases under varying effective stresses,providing a comprehensive dataset that allows the combined effects of effective stress and gas adsorption on permeability anisotropy to be robustly assessed on the same samples.The results demonstrated that all coal samples exhibited evident permeability anisotropy,with ratios ranging from 1.11 to 6.55.For the first time,quantitative relationships between the anisotropy ratio,effective stress,and initial permeability were established for each of the three injection gases,highlighting how gas adsorption and effective stress changes both anisotropic permeability magnitude and ratio.These findings provide new insights into the directional flow behavior of gases in coal seams,with implications for underground compressed air energy storage and CO_(2) sequestration.
基金support of the National Natural Science Foundation of China(U23B6004 and 52404045)the CAST Young Talent Support Program,Doctoral Student Special Project.
文摘During gas extraction from deep coal,the rock endures high effective stress,with both the time-dependent deformation and anisotropic structure of the rock controlling the permeability evolution.To reveal this phenomenon,a numerical simulation framework of the finite volume method and transient embedded discrete fracture model is proposed to establish a new constitutive model that links poroelastoplastic deformation,adsorption-induced swelling,and aperture compression.From this model,anisotropic permeability tensors were derived to further achieve the simulation of coevolution.Meanwhile,our permeability model was verified against the measured permeability data,and the history match of the numerical model showed better results where the mismatch was less than 5%.The results indicate that(1)the long-term permeability evolution clearly showed the competitive effects of multiple deformation mechanisms,which involves three stages:compaction-dominated decline,adsorption-dominated rebound,and creep-controlled loss.(2)The increased number of compressible cleats/fractures accelerated the initial permeability decline,while the increased desorption-induced strain promoted faster rebound and enhancement and higher viscosity coefficients enhanced the creep effect,which led to significant long-term permeability loss.(3)Massive hydraulic fracturing created a larger drainage area,accelerating methane desorption and causing sharp permeability rebound with reduced residual gas,which shows that the permeability remained higher than the initial values even after the extensive extraction via the fractured horizontal wells.The permeability evolution mechanisms displayed varying properties,such as coal rank and burial depth,and distinct characteristics.A precise understanding of multiple competitive stress effects is crucial for optimizing coalbed methane extraction techniques and improving recovery efficiency.
基金funded by the Ministry of Science and Higher Education of the Russian Federation(Project No.FSNM-2024-0005).
文摘Permeability is one of the main oil reservoir characteristics.It affects potential oil production,well-completion technologies,the choice of enhanced oil recovery methods,and more.The methods used to determine and predict reservoir permeability have serious shortcomings.This article aims to refine and adapt machine learning techniques using historical data from hydrocarbon field development to evaluate and predict parameters such as the skin factor and permeability of the remote reservoir zone.The article analyzes data from 4045 wells tests in oil fields in the Perm Krai(Russia).An evaluation of the performance of different Machine Learning(ML)al-gorithms in the prediction of the well permeability is performed.Three different real datasets are used to train more than 20 machine learning regressors,whose hyperparameters are optimized using Bayesian Optimization(BO).The resulting models demonstrate significantly better predictive performance compared to traditional methods and the best ML model found is one that never was applied before to this problem.The permeability prediction model is characterized by a high R^(2) adjusted value of 0.799.A promising approach is the integration of machine learning methods and the use of pressure recovery curves to estimate permeability in real-time.The work is unique for its approach to predicting pressure recovery curves during well operation without stopping wells,providing primary data for interpretation.These innovations are exclusive and can improve the accuracy of permeability forecasts.It also reduces well downtime associated with traditional well-testing procedures.The proposed methods pave the way for more efficient and cost-effective reservoir development,ultimately sup-porting better decision-making and resource optimization in oil production.
基金Supported by the China National Petroleum Corporation Major Science and Technology Project(2023ZZ19-01,2023ZZ19-07).
文摘Based on the waterflooding development in carbonate reservoirs in the Middle East,this study analyzes the geological characteristics and waterflooding behaviors/patterns of different types of high permeability zones(HPZs),and proposes rational waterflooding strategies and modes.Four types of HPZs,i.e.sedimentation-dominated,sedimentation-diagenesis coupling,biogenic and composite,are identified in the carbonate reservoirs in the Middle East.Based on their distribution patterns,flow mechanisms,and waterflooding behaviors/patterns,five waterflooding modes are established:(1)the mode with stepwise-infilled areal vertical well pattern,for composite HFZs in patchy distribution;(2)the mode with regular row vertical well pattern for TypeⅠchannel“network”HFZs(with dominant water flow pathways at the base),and the mode with irregular differentiated vertical well pattern for TypeⅡchannel“network”HFZs(where multi-stage superimposition leads to“layered flooding”),for sedimentation-diagenesis coupling HFZs;(3)the mode with row horizontal wells through bottom injection and top production,for biogenic HFZs characterized by thin,contiguous distribution and rapid advancing of injected water along a工-shaped path;and(4)the mode with progressive waterflooding through edge water injection via vertical well and oil production via horizontal well,for sedimentation-dominated HFZs characterized by thick,contiguous distribution and flood first in upper anti-rhythmic reservoirs.Development practices demonstrate that the proposed waterflooding modes are efficient in the highly heterogeneous carbonate reservoirs in the Middle East,with balanced employment of reserves in the adjacent reservoirs and enhanced oil recovery.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA14010302)the National Key Research and Development Program of China(No.2017YFC0603104)the Ministère de l’Enseignement Supérieur et de la Recherche,Agence Nigérienne des Allocations et des Bourses,ANAB-Niger(No.2015563007).
文摘Carbonates present complex pore systems that strongly influence the physical properties and their interrelationships.This study proposes a new approach to establish pore-type mixing-based permeability transforms by integrating well-log and core data.We investigate the influence of pore-structure heterogeneity on permeability and velocity through the rock-frame flexibility factors(γ and γ_(μ)),derivable using standard sonic and density logs.We derive permeability transforms,with correlation coefficients,R of 0.8 to 0.9,from core measurements and pore-structure variations-dependent physical parameters,namely the porosity exponent(m),Poisson’s ratio(σ),velocity deviation log(VDL),and velocity ratio(VR).Through extrapolation using log-data,the m-and VDL-based correlations provide significantly better permeability estimates,with the highest accuracy attained with the m-based correlation,whereas the VR-andσ-based correlations lead to permeability overes-timation for high porosities.We plotted log-derived porosity vs.permeability,obtained applying the m-based correlation,to generate consistent porosity-permeability relationships,which account for pore-structure heterogeneity,by sorting the scattering points into distinct groups/trends by considering the variations of pore-structure types and abundance of a specific porosity.For the studied oilfield,three porosity-permeability relationships are identified,with correlation coefficients approaching 0.9,thus validating the approach and supporting its application in petrophysically similar reservoirs.
基金Projects(12072102,12102129)supported by the National Natural Science Foundation of ChinaProject(DM2022B01)supported by the Key Laboratory of Safe Mining of Deep Metal Mines,Ministry of Education,ChinaProject(JZ-008)supported by the Six Talent Peaks Project in Jiangsu Province,China。
文摘In this study,a series of triaxial tests are conducted on sandstone specimens to investigate the evolution of their mechanics and permeability characteristics under the combined action of immersion corrosion and seepage of different chemical solutions.It is observed that with the increase of confining pressure,the peak stress,dilatancy stress,dilatancy stress ratio,peak strain,and elastic modulus of the sandstone increase while the Poisson ratio decreases and less secondary cracks are produced when the samples are broken.The pore pressure and confining pressure have opposite influences on the mechanical properties.With the increase of the applied axial stress,three stages are clearly identified in the permeability evolution curves:initial compaction stage,linear elasticity stage and plastic deformation stage.The permeability reaches the maximum value when the highest volumetric dilatancy is obtained.In addition,the hydrochemical action of salt solution with pH=7 and 4 has an obvious deteriorating effect on the mechanical properties and induces the increase of permeability.The obtained results will be useful in engineering to understand the mechanical and seepage properties of sandstone under the coupled chemical-seepage-stress multiple fields.
基金supported by National Key Research and Development Program of China(Grant Nos.:2022YFC3400504 and 2023YFC2305904)the Strategic Priority Research Program of the Chinese Academy of Sciences,China(Grant Nos.:XDB0830203 and XDB0830200)+2 种基金the National Natural Science Foundation of China(Grant Nos.:82204278,31960198,T2225002,and 82273855)SIMM-SHUTCM Traditional Chinese Medicine Innovation Joint Research Program,China(Grant No.:E2G805H)Shanghai Municipal Science and Technology Major Project,China,and Key Technologies R&D Program of Guangdong Province,China(Grant No.:2023B1111030004).
文摘Kirsten rat sarcoma viral oncogene homolog(KRAS)protein inhibitors are a promising class of therapeutics,but research on molecules that effectively penetrate the blood-brain barrier(BBB)remains limited,which is crucial for treating central nervous system(CNS)malignancies.Although molecular generation models have recently advanced drug discovery,they often overlook the complexity of biological and chemical factors,leaving room for improvement.In this study,we present a structureconstrained molecular generation workflow designed to optimize lead compounds for both drug efficacy and drug absorption properties.Our approach utilizes a variational autoencoder(VAE)generative model integrated with reinforcement learning for multi-objective optimization.This method specifically aims to enhance BBB permeability(BBBp)while maintaining high-affinity substructures of KRAS inhibitors.To support this,we incorporate a specialized KRAS BBB predictor based on active learning and an affinity predictor employing comparative learning models.Additionally,we introduce two novel metrics,the knowledge-integrated reproduction score(KIRS)and the composite diversity score(CDS),to assess structural performance and biological relevance.Retrospective validation with KRAS inhibitors,AMG510 and MRTX849,demonstrates the framework’s effectiveness in optimizing BBBp and highlights its potential for real-world drug development applications.This study provides a robust framework for accelerating the structural enhancement of lead compounds,advancing the drug development process across diverse targets.
