Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock propert...Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock properties.Given the multiscale characteristics of rock pore structures,direct three-dimensional imaging at sub-micrometer and nanometer scales is typically infeasible.This study introduces a method for reconstructing porous media using multidimensional data,which combines one-dimensional pore structure parameters with two-dimensional images to reconstruct three-dimensional models.The pore network model(PNM)is stochastically reconstructed using one-dimensional parameters,and a generative adversarial network(GAN)is utilized to equip the PNM with pore morphologies derived from two-dimensional images.The digital rocks generated by this method possess excellent controllability.Using Berea sandstone and Grosmont carbonate samples,we performed digital rock reconstructions based on PNM extracted by the maximum ball algorithm and compared them with stochastically reconstructed PNM.Pore structure parameters,permeability,and formation factors were calculated.The results show that the generated samples exhibit good consistency with real samples in terms of pore morphology,pore structure,and physical properties.Furthermore,our method effectively supplements the micropores not captured in CT images,demonstrating its potential in multiscale carbonate samples.Thus,the proposed reconstruction method is promising for advancing porous media property research.展开更多
A series of granular activated carbons （GACs） were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET speci...A series of granular activated carbons （GACs） were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET specific surface area （SBEr）, total pore volume （Vr） and average pore diameter （da） were measured and cal- culated as well as process parameters such as yield of char （CY） and burn-off （B）. The relationship between the pore structural parameters of the GAC from coal blend （BC-GAC） and the ones of the GACs from corresponding single coals （SC-GACs） was analyzed, in which an index, the relative error （δ）, was presented to define the bias between fitted values and experimental values of these parameters of the BC-GACs. The results show that the BC-GAC keeps qualitatively the pore structural features of the SC-GACs; as concerned as the quantitative relationship, the pore structural parameters of the BC-GAC from coal blend consisting of non-caking coals can be obtained by adding proportionally the pore structural parameters of the SC-GACs with a less than 10%. Meanwhile, for the BC-GAC from coal blend containing weak caking bituminous coal, the δ increases up to 25% and the experimental pore size distribution differs greatly from the fitted one.展开更多
We considered adding different amounts(1%,2%,3%,and 4%)of EMR to prepare manganese residue polymer magnesium phosphate cement composite(EMR-PMPC).The influence mechanism of EMR doping on the early macroscopic and micr...We considered adding different amounts(1%,2%,3%,and 4%)of EMR to prepare manganese residue polymer magnesium phosphate cement composite(EMR-PMPC).The influence mechanism of EMR doping on the early macroscopic and microscopic pore structure properties of composites was studied by combining macroscopic and microscopic testing methods.The experimental results show that the addition of EMR can improve the working performance of the slurry and enhance the strength in the later stage,the 28 d compressive strength value of the slurry doped with EMR can reach 49.5 MPa.The Mn element and NH4_(+)^(-)N in EMR react with MgO in the raw material to produce Struvite and Mn(OH)_(2)and Mn_(3)(PO_(4))·6H_(2)O gel,the hydration products coexist with each other and lap each other to form a dense microfine structure and effectively refine the pores.The hydration process consists of five stages,mainly concentrated in the first 10 h or less to exothermic mainly,infrared spectral absorption band is mainly composed of O-H bond,H-O-H bond,PO_(4)bond and metal oxygen bond 3 parts,EMR makes the wave number of the absorption band from the ground wave number to the high wave number.EMR doping T_(2)spectral relaxation time will lag behind,the pore size distribution changes.The total porosity and bound fluid saturation decrease with increasing,the free fluid saturation shows the opposite trend,the permeability decreases and then increases.展开更多
Structural damage from sample preparation processes such as cutting and polishing may change the pore structure of rocks.However,changes in pore structure caused by this structural damage from crushing and its effect ...Structural damage from sample preparation processes such as cutting and polishing may change the pore structure of rocks.However,changes in pore structure caused by this structural damage from crushing and its effect on marine continental transitional shale have not been well documented.The changes of microscopic pore structure in marine continental transitional shale during the sample preparation have important research value for subsequent exploration and development of shale gas.In this study,the pore structures of transitional shale samples from the Shanxi-Taiyuan Formation of the Southern North China Basin under different degrees of damage were analyzed through low-temperature N;adsorption experiments,combined with X-ray diffraction,total organic carbon,vitrinite reflectance analysis,and scanning electron microscopy.The results showed that(1)With increasing structural damage,the specific surface area(SSA)changed within relatively tight bounds,while the pore volume(PV)varied significantly,and the growth rate(maximum)exhibited a certain critical value with the crushing mesh number increasing from 20 to 200.(2)The ratio of SSA to PV can be used as a potential proxy for evaluating the influence of changes in the pore structure.(3)Correlation analysis revealed that the microscopic pore structure of marine continental transitional shale from the Shanxi-Taiyuan Formations is mainly controlled by organic matter and clay minerals.Clay minerals play a leading role in the development of microscopic pores and changes in pore structure.展开更多
Existing imaging techniques cannot simultaneously achieve high resolution and a wide field of view,and manual multi-mineral segmentation in shale lacks precision.To address these limitations,we propose a comprehensive...Existing imaging techniques cannot simultaneously achieve high resolution and a wide field of view,and manual multi-mineral segmentation in shale lacks precision.To address these limitations,we propose a comprehensive framework based on generative adversarial network(GAN)for characterizing pore structure properties of shale,which incorporates image augmentation,super-resolution reconstruction,and multi-mineral auto-segmentation.Using real 2D and 3D shale images,the framework was assessed through correlation function,entropy,porosity,pore size distribution,and permeability.The application results show that this framework enables the enhancement of 3D low-resolution digital cores by a scale factor of 8,without paired shale images,effectively reconstructing the unresolved fine-scale pores under a low resolution,rather than merely denoising,deblurring,and edge clarification.The trained GAN-based segmentation model effectively improves manual multi-mineral segmentation results,resulting in a strong resemblance to real samples in terms of pore size distribution and permeability.This framework significantly improves the characterization of complex shale microstructures and can be expanded to other heterogeneous porous media,such as carbonate,coal,and tight sandstone reservoirs.展开更多
With the development of coal mine equipment mechanization, the wide application of </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">...With the development of coal mine equipment mechanization, the wide application of </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">hole instead of roadway</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> technology greatly reduces the cost of gas control engineering, but puts forward higher requirements for the effect of gas drainage. At present, the drainage effect of coal mine inspection boreholes is mainly evaluated by the drilling field, but the flow rate and gas concentration of each borehole in the drilling field are not the same, which causes the gas drainage effect not to be correctly mastered. In the present study, the pressure relief drilling in the goaf of the working face of a typical multi-coal seam group high gas outburst mining area was taken as the research object. Through the newly developed portable drilling inspection device, the pure amount of drilling drainage was investigated, and the drilling design was dynamically adjusted. The enhancement of the goaf pressure relief gas control effect ensures the gas safety of the mining face. At the same time, this improves the gas extraction rate and reduces the emission of greenhouse gases. If the data from the borehole investigation can be transmitted in real time and analyzed in big data, the optimal extraction negative pressure can be predicted through a regression algorithm. Under the control of the negative pressure of each borehole by the actuator, the extraction system can have the function of intelligent judgment.展开更多
Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth.However,it is still a challenge to widely tune str...Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth.However,it is still a challenge to widely tune structure parameters of scaffolds by conventional methods because of inevitable pore geometrical deformation and poor pore interconnectivity.Here,the long-term in vivo biological performances of nonstoichiometric bioceramic scaffolds with different pore dimensions were assessed in critical-size femoral bone defect model.The 6%Mg-substituted wollastonite(CSi-Mg6)powders were prepared via wet-chemical precipitation and the scaffolds elaborately printed by ceramic stereolithography,displaying designed constant pore strut and tailorable pore height(200,320,450,600μm),were investigated thoroughly in the bone regeneration process.Together with detailed structural stability and mechanical properties were collaboratively outlined.BothμCT and histological analyses indicated that bone tissue ingrowth was retarded in 200μm scaffolds in the whole stage(2-16 weeks)but the 320μm scaffolds showed appreciable bone tissue in the center of porous constructs at 6-10 weeks and matured bone tissue were uniformly invaded in the whole pore networks at 16 weeks.Interestingly,the neo-tissue ingrowth was facilitated in the 450μm and 600μm scaffolds after 2 weeks and higher extent of bone regeneration and remodeling at the later stage.These new findings provide critical information on how engineered porous architecture impact bone regeneration in vivo.Simultaneously,this study shows important implications for optimizing the porous scaffolds design by advanced additive manufacture technique to match the clinical translation with high performance.展开更多
For shale of Lower Silurian Longmaxi Formation in Chongqing,southeast Sichuan Basin,characteristics of micro-nano pores in marine shale reservoirs were well studies by means of Field-Emission Scanning Electron Microsc...For shale of Lower Silurian Longmaxi Formation in Chongqing,southeast Sichuan Basin,characteristics of micro-nano pores in marine shale reservoirs were well studies by means of Field-Emission Scanning Electron Microscope and Low-temperature Low-pressure Adsorption Experiment of CO_(2)and N_(2).Results showed that six types of pore were developed in the shale of Longmaxi Formation,i.e.,organic pores,intergranular pores,intragranular pores,intercrystalline pores,dissolution pores and microfractures,among which the organic pores and intragranular pores in interlayers of clay minerals were most developed,and a plenty of dissolution pores were also well developed because of high thermal evolution degree.BET specific surface area of the shale in Longmaxi Formation ranged from 3.5 to 18.1 m^(2)/g,BJH total pore volume was from 0.00234 to 0.01338 cm^(3)/g,DA specific surface area of micropores vaired from 1.3 to 7.3 m^(2)/g,and DA pore volume ranged from 0.00052 to 0.00273 cm^(3)/g.The specific surface area of micropores in the shale accounted for 23.1%-80.2%of total specific surface area with an average of 50.3%,and the pore volume of micropores accounted for 12.1%-48.5%of total pore volume with an average of 32.3%.Micropore was the main storage space in shale reservoir for methane adsorption,that because capacities of specific surface area provided by micropores were considerably greater than those provided by mesopores and macropores.Pore size distribution of the shale was complex,and multiple different peaks occurred in the pore size curves,showing two or three peaks in the range from 0 to 100 nm and four peaks occasionally.TOC had a good linear relationship with pore structure parameters of micropores,mesopores t macropores and total pores in the shale,indicating that TOC was the most important control factor for micron-to nano-pore structure in the shale.After normalization of pore structure parameters to TOC,the pore structure parameters of total pores and mesopores t macropores,had positive linear relationships with content of clay minerals but negative linear relationships with content of brittle minerals,indicating that clay minerals and brittle minerals mainly controlled development of mesopores and macropores in the shale.展开更多
基金supported by the Shandong Provincial Natural Science Foundation(ZR2024MD116)National Natural Science Foundation of China(Grant Nos.42174143,42004098)Technology Innovation Leading Program of Shaanxi(No.2024 ZC-YYDP-27).
文摘Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock properties.Given the multiscale characteristics of rock pore structures,direct three-dimensional imaging at sub-micrometer and nanometer scales is typically infeasible.This study introduces a method for reconstructing porous media using multidimensional data,which combines one-dimensional pore structure parameters with two-dimensional images to reconstruct three-dimensional models.The pore network model(PNM)is stochastically reconstructed using one-dimensional parameters,and a generative adversarial network(GAN)is utilized to equip the PNM with pore morphologies derived from two-dimensional images.The digital rocks generated by this method possess excellent controllability.Using Berea sandstone and Grosmont carbonate samples,we performed digital rock reconstructions based on PNM extracted by the maximum ball algorithm and compared them with stochastically reconstructed PNM.Pore structure parameters,permeability,and formation factors were calculated.The results show that the generated samples exhibit good consistency with real samples in terms of pore morphology,pore structure,and physical properties.Furthermore,our method effectively supplements the micropores not captured in CT images,demonstrating its potential in multiscale carbonate samples.Thus,the proposed reconstruction method is promising for advancing porous media property research.
基金financially supported by the National High-Tech Research and Development Program of China (No.2008AA05Z308)the National Natural Science Foundation of China (No.20776150)
文摘A series of granular activated carbons （GACs） were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET specific surface area （SBEr）, total pore volume （Vr） and average pore diameter （da） were measured and cal- culated as well as process parameters such as yield of char （CY） and burn-off （B）. The relationship between the pore structural parameters of the GAC from coal blend （BC-GAC） and the ones of the GACs from corresponding single coals （SC-GACs） was analyzed, in which an index, the relative error （δ）, was presented to define the bias between fitted values and experimental values of these parameters of the BC-GACs. The results show that the BC-GAC keeps qualitatively the pore structural features of the SC-GACs; as concerned as the quantitative relationship, the pore structural parameters of the BC-GAC from coal blend consisting of non-caking coals can be obtained by adding proportionally the pore structural parameters of the SC-GACs with a less than 10%. Meanwhile, for the BC-GAC from coal blend containing weak caking bituminous coal, the δ increases up to 25% and the experimental pore size distribution differs greatly from the fitted one.
基金Funden by the National Natural Science Foundation of China(Nos.51868044 and 52178216)the Basic Research Program of Qinghai Province(No.2022-ZJ-921)+2 种基金the Innovation Star”Project for Excellent Postgraduates in Gansu Province(No.2022-CXZX-450)the Hongliu First-class Discipline Construction Program of Lanzhou University of TechnologyScience and Technology Project of Gansu Provincial Department of Transportation(No.2022-23)。
文摘We considered adding different amounts(1%,2%,3%,and 4%)of EMR to prepare manganese residue polymer magnesium phosphate cement composite(EMR-PMPC).The influence mechanism of EMR doping on the early macroscopic and microscopic pore structure properties of composites was studied by combining macroscopic and microscopic testing methods.The experimental results show that the addition of EMR can improve the working performance of the slurry and enhance the strength in the later stage,the 28 d compressive strength value of the slurry doped with EMR can reach 49.5 MPa.The Mn element and NH4_(+)^(-)N in EMR react with MgO in the raw material to produce Struvite and Mn(OH)_(2)and Mn_(3)(PO_(4))·6H_(2)O gel,the hydration products coexist with each other and lap each other to form a dense microfine structure and effectively refine the pores.The hydration process consists of five stages,mainly concentrated in the first 10 h or less to exothermic mainly,infrared spectral absorption band is mainly composed of O-H bond,H-O-H bond,PO_(4)bond and metal oxygen bond 3 parts,EMR makes the wave number of the absorption band from the ground wave number to the high wave number.EMR doping T_(2)spectral relaxation time will lag behind,the pore size distribution changes.The total porosity and bound fluid saturation decrease with increasing,the free fluid saturation shows the opposite trend,the permeability decreases and then increases.
基金the financial support by the National Natural Science Foundation of China(Grant No.41927801)。
文摘Structural damage from sample preparation processes such as cutting and polishing may change the pore structure of rocks.However,changes in pore structure caused by this structural damage from crushing and its effect on marine continental transitional shale have not been well documented.The changes of microscopic pore structure in marine continental transitional shale during the sample preparation have important research value for subsequent exploration and development of shale gas.In this study,the pore structures of transitional shale samples from the Shanxi-Taiyuan Formation of the Southern North China Basin under different degrees of damage were analyzed through low-temperature N;adsorption experiments,combined with X-ray diffraction,total organic carbon,vitrinite reflectance analysis,and scanning electron microscopy.The results showed that(1)With increasing structural damage,the specific surface area(SSA)changed within relatively tight bounds,while the pore volume(PV)varied significantly,and the growth rate(maximum)exhibited a certain critical value with the crushing mesh number increasing from 20 to 200.(2)The ratio of SSA to PV can be used as a potential proxy for evaluating the influence of changes in the pore structure.(3)Correlation analysis revealed that the microscopic pore structure of marine continental transitional shale from the Shanxi-Taiyuan Formations is mainly controlled by organic matter and clay minerals.Clay minerals play a leading role in the development of microscopic pores and changes in pore structure.
基金Supported by the National Natural Science Foundation of China(U23A20595,52034010,52288101)National Key Research and Development Program of China(2022YFE0203400)+1 种基金Shandong Provincial Natural Science Foundation(ZR2024ZD17)Fundamental Research Funds for the Central Universities(23CX10004A).
文摘Existing imaging techniques cannot simultaneously achieve high resolution and a wide field of view,and manual multi-mineral segmentation in shale lacks precision.To address these limitations,we propose a comprehensive framework based on generative adversarial network(GAN)for characterizing pore structure properties of shale,which incorporates image augmentation,super-resolution reconstruction,and multi-mineral auto-segmentation.Using real 2D and 3D shale images,the framework was assessed through correlation function,entropy,porosity,pore size distribution,and permeability.The application results show that this framework enables the enhancement of 3D low-resolution digital cores by a scale factor of 8,without paired shale images,effectively reconstructing the unresolved fine-scale pores under a low resolution,rather than merely denoising,deblurring,and edge clarification.The trained GAN-based segmentation model effectively improves manual multi-mineral segmentation results,resulting in a strong resemblance to real samples in terms of pore size distribution and permeability.This framework significantly improves the characterization of complex shale microstructures and can be expanded to other heterogeneous porous media,such as carbonate,coal,and tight sandstone reservoirs.
文摘With the development of coal mine equipment mechanization, the wide application of </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">hole instead of roadway</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> technology greatly reduces the cost of gas control engineering, but puts forward higher requirements for the effect of gas drainage. At present, the drainage effect of coal mine inspection boreholes is mainly evaluated by the drilling field, but the flow rate and gas concentration of each borehole in the drilling field are not the same, which causes the gas drainage effect not to be correctly mastered. In the present study, the pressure relief drilling in the goaf of the working face of a typical multi-coal seam group high gas outburst mining area was taken as the research object. Through the newly developed portable drilling inspection device, the pure amount of drilling drainage was investigated, and the drilling design was dynamically adjusted. The enhancement of the goaf pressure relief gas control effect ensures the gas safety of the mining face. At the same time, this improves the gas extraction rate and reduces the emission of greenhouse gases. If the data from the borehole investigation can be transmitted in real time and analyzed in big data, the optimal extraction negative pressure can be predicted through a regression algorithm. Under the control of the negative pressure of each borehole by the actuator, the extraction system can have the function of intelligent judgment.
基金support from the National Key Research and Development Program of China(2017YFE0117700,2018YC1105401)National Natural Science Foundation of China(81772311,81871775)the Science and Technology Department of Zhejiang Province Foundation(LGF18E020001,LGF20H060016).
文摘Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth.However,it is still a challenge to widely tune structure parameters of scaffolds by conventional methods because of inevitable pore geometrical deformation and poor pore interconnectivity.Here,the long-term in vivo biological performances of nonstoichiometric bioceramic scaffolds with different pore dimensions were assessed in critical-size femoral bone defect model.The 6%Mg-substituted wollastonite(CSi-Mg6)powders were prepared via wet-chemical precipitation and the scaffolds elaborately printed by ceramic stereolithography,displaying designed constant pore strut and tailorable pore height(200,320,450,600μm),were investigated thoroughly in the bone regeneration process.Together with detailed structural stability and mechanical properties were collaboratively outlined.BothμCT and histological analyses indicated that bone tissue ingrowth was retarded in 200μm scaffolds in the whole stage(2-16 weeks)but the 320μm scaffolds showed appreciable bone tissue in the center of porous constructs at 6-10 weeks and matured bone tissue were uniformly invaded in the whole pore networks at 16 weeks.Interestingly,the neo-tissue ingrowth was facilitated in the 450μm and 600μm scaffolds after 2 weeks and higher extent of bone regeneration and remodeling at the later stage.These new findings provide critical information on how engineered porous architecture impact bone regeneration in vivo.Simultaneously,this study shows important implications for optimizing the porous scaffolds design by advanced additive manufacture technique to match the clinical translation with high performance.
基金This work was supported by National Natural Science Foundation of China(No.41690134)National Science and Technology Major Project of China(No.2017ZX05035002-006).
文摘For shale of Lower Silurian Longmaxi Formation in Chongqing,southeast Sichuan Basin,characteristics of micro-nano pores in marine shale reservoirs were well studies by means of Field-Emission Scanning Electron Microscope and Low-temperature Low-pressure Adsorption Experiment of CO_(2)and N_(2).Results showed that six types of pore were developed in the shale of Longmaxi Formation,i.e.,organic pores,intergranular pores,intragranular pores,intercrystalline pores,dissolution pores and microfractures,among which the organic pores and intragranular pores in interlayers of clay minerals were most developed,and a plenty of dissolution pores were also well developed because of high thermal evolution degree.BET specific surface area of the shale in Longmaxi Formation ranged from 3.5 to 18.1 m^(2)/g,BJH total pore volume was from 0.00234 to 0.01338 cm^(3)/g,DA specific surface area of micropores vaired from 1.3 to 7.3 m^(2)/g,and DA pore volume ranged from 0.00052 to 0.00273 cm^(3)/g.The specific surface area of micropores in the shale accounted for 23.1%-80.2%of total specific surface area with an average of 50.3%,and the pore volume of micropores accounted for 12.1%-48.5%of total pore volume with an average of 32.3%.Micropore was the main storage space in shale reservoir for methane adsorption,that because capacities of specific surface area provided by micropores were considerably greater than those provided by mesopores and macropores.Pore size distribution of the shale was complex,and multiple different peaks occurred in the pore size curves,showing two or three peaks in the range from 0 to 100 nm and four peaks occasionally.TOC had a good linear relationship with pore structure parameters of micropores,mesopores t macropores and total pores in the shale,indicating that TOC was the most important control factor for micron-to nano-pore structure in the shale.After normalization of pore structure parameters to TOC,the pore structure parameters of total pores and mesopores t macropores,had positive linear relationships with content of clay minerals but negative linear relationships with content of brittle minerals,indicating that clay minerals and brittle minerals mainly controlled development of mesopores and macropores in the shale.
