To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insul...To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.展开更多
Based on the organic geochemical data and the molecular and stable carbon isotopic compositions of natural gas of the Lower Permian Fengcheng Formation in the western Central Depression of Junggar Basin,combined with ...Based on the organic geochemical data and the molecular and stable carbon isotopic compositions of natural gas of the Lower Permian Fengcheng Formation in the western Central Depression of Junggar Basin,combined with sedimentary environment analysis and hydrocarbon-generating simulation,the gas-generating potential of the Fengcheng source rock is evaluated,the distribution of large-scale effective source kitchen is described,the genetic types of natural gas are clarified,and four types of favorable exploration targets are selected.The results show that:(1)The Fengcheng Formation is a set of oil-prone source rocks,and the retained liquid hydrocarbon is conducive to late cracking into gas,with characteristics of high gas-generating potential and late accumulation;(2)The maximum thickness of Fengcheng source rock reaches 900 m.The source rock has entered the main gas-generating stage in Penyijingxi and Shawan sags,and the area with gas-generating intensity greater than 20×10^(8) m^(3)/km^(2) is approximately 6500 km^(2).(3)Around the western Central Depression,highly mature oil-type gas with light carbon isotope composition was identified to be derived from the Fengcheng source rocks mainly,while the rest was coal-derived gas from the Carboniferous source rock;(4)Four types of favorable exploration targets with exploration potential were developed in the western Central Depression which are structural traps neighboring to the source,stratigraphic traps neighboring to the source,shale-gas type within the source,and structural traps within the source.Great attention should be paid to these targets.展开更多
The year of 2024 marks the 50th anniversary of the publication of Petroleum Exploration and Development.For half a century,Petroleum Exploration and Development has been committed to disseminating petroleum technology...The year of 2024 marks the 50th anniversary of the publication of Petroleum Exploration and Development.For half a century,Petroleum Exploration and Development has been committed to disseminating petroleum technology,witnessing and recording the glorious journey of China's petroleum industry from being weak to becoming strong.The journal has also become a bright banner in China's petroleum technology industry.展开更多
Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fra...Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated.展开更多
Six hydrothermal sediment samples were collected from the Xunmei and Tongguan hydrothermal fields along the southern Mid-Atlantic Ridge during the China Ocean Cruise DY46 in 2017.Sulfides and oxides in the samples wer...Six hydrothermal sediment samples were collected from the Xunmei and Tongguan hydrothermal fields along the southern Mid-Atlantic Ridge during the China Ocean Cruise DY46 in 2017.Sulfides and oxides in the samples were separated,and Cu and Zn isotope compositions were analyzed.Results show that the ranges ofδ^(65)Cu values of the bulk sediments,sulfides,and oxides were 0.36‰-2.46‰,-0.21‰-1.10‰,and 0.68‰-1.52‰,respectively.Theδ^(65)Cu values of sulfides in four samples(46II-14,46II-30,46III-06,and 46II-09)were relatively low(-0.21‰-0.50‰),corresponding to theδ^(65)Cu values of sulfides from inactive old hydrothermal chimneys in northern Mid-Atlantic Ridge(n MAR),suggesting that the sulfides in the sediments were originated from collapsed dead chimney mainly.While theδ^(65)Cu values of the other two samples(46III-02 and 46III-08)were relatively high(1.10‰-0.96‰),corresponding to theδ^(65)Cu values for active hydrothermal chimneys sulfides in n MAR,which indicated that the sulfides in these two samples might mainly come from sulfide particles settled from active hydrothermal plume.Because of the high density of sulfide particles,they tended to settle near the hydrothermal vents first.Therefore,highδ^(65)Cu values of sulfides in 46III-02 and 46III-08 implied that undiscovered active hydrothermal vents near the sampling positions of 46III-02 in the Xunmei hydrothermal field and 46III-08 in the Tongguan hydrothermal field.Theδ^(66)Zn values of hydrothermal sediments and sulfides ranged 0.11‰-0.43‰and 0.29‰-0.67‰,respectively.In the four samples from the Xunmei hydrothermal field,a positive correlation was found between the distance of the sampling position from sulfide mineralized spot and the Zn isotopic ratio,showing that the greater the distance from the mineralized spot,the heavier the Zn isotope composition as seen in two samples(46II-30 and 46II-14)of the Xunmei-3 spot.This result aligned with the findings of Wilkinson et al.(2005)and Baumgartner et al.(2023),suggesting that the lower the Zn isotope composition,the closer it is to the hydrothermal vent.However,in the Xunmei hydrothermal field,the Zn isotope composition in the other two samples(46III-02and 46III-06)showed the opposite trend.This indicated that there might be an active hydrothermal vent near the sampling location of sample 46III-02.This observation aligned with the Cu isotope analysis results.This study showed that Cu-Zn isotopes are good indicators for understanding the formation mechanisms of hydrothermal sediments and for locating active hydrothermal vents.展开更多
Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful migration.While age and experience have been identified as key factor influencing migration route s...Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful migration.While age and experience have been identified as key factor influencing migration route selection among soaring raptors in the African-Eurasian Flyway,how they shape the migration route of soaring raptors in East Asia is still largely unknown.In this study,we investigated potential variations in the routes and timing in autumn migration of juvenile and older soaring birds,using count data of Greater Spotted Eagles(Clanga clanga)from two coastal sites and two inland sites in China.From 2020 to 2023,we recorded a total of 340 individuals,with the highest site averaging over 90 individuals per autumn,making it one of the world’s top single-season counts and thus a globally important site for this species.We found that 82% and 61% records from coastal sites were juveniles,significantly higher than inland sites(15% and 24%).Juveniles at all four sites exhibited markedly earlier median passage time than non-juveniles,with brief overlapping in their main migration periods.Both coastal sites are located on the tip of peninsulas stretching southwest,requiring long overwater flights if crossing the Bohai Bay or Beibu Gulf,which would be energetically demanding and increase mortality risk.Experienced individuals may have learned to avoid such terrain and subsequent detour,while juveniles are more prone to enter these peninsulas due to lack of experience and opportunities for social learning,or following other raptor species that are more capable of powered flight.Our findings highlight the importance of age and experience in migration route selection of large soaring birds.展开更多
Production performance of the Wufeng-Longmaxi shales varies significantly among Fuling,Weirong,and Wulong fields in the Sichuan Basin.Total organic carbon(TOC)content,mineralogy,and organic matter(OM)pore characterist...Production performance of the Wufeng-Longmaxi shales varies significantly among Fuling,Weirong,and Wulong fields in the Sichuan Basin.Total organic carbon(TOC)content,mineralogy,and organic matter(OM)pore characteristics are investigated to identify key factors governing sweet spots.Siliceous shales with good preservation conditions in the Fuling Field exhibit large thickness,high TOC content and thin-section porosity(TSP),and well-developed OM macropores,thus high initial production and estimated ultimate recovery(EUR).Thin carbonate-containing siliceous shales with good preservation conditions in the Weirong Field feature medium-to-high TOC and well-developed OM macropores but low TSP,leading to high initial production but low EUR.Siliceous shales with poor preservation conditions in the Wulong Field are characterized by large thickness,high TOC,low TSP and poorly-developed OM macropores,causing low initial production and EUR.Both sedimentary and preservation conditions are intrinsic decisive factors of sweet spots,as they control the mineral composition,TOC,and OM macropore development.Deep-water shales in transgressive systems tracts(TSTs)exhibit better-developed OM macropores and greater TOC compared to highstand systems tracts(HSTs).OM macropores are most prevalent in siliceous shales,followed by carbonate-containing siliceous shales and then argillaceous shales.Furthermore,good preservation conditions are conducive to retain OM macropores with low pore aspect ratio(PAR).Comparison among the three fields shows that high-TOC silicious shales with good preservation conditions are the highest in TSP and EUR.Therefore,organic richness,lithofacies,and preservation conditions are the major factors which determine OM pore development,governing the sweet spots of the Wufeng-Longmaxi shales.展开更多
Deep learning, especially through convolutional neural networks (CNN) such as the U-Net 3D model, has revolutionized fault identification from seismic data, representing a significant leap over traditional methods. Ou...Deep learning, especially through convolutional neural networks (CNN) such as the U-Net 3D model, has revolutionized fault identification from seismic data, representing a significant leap over traditional methods. Our review traces the evolution of CNN, emphasizing the adaptation and capabilities of the U-Net 3D model in automating seismic fault delineation with unprecedented accuracy. We find: 1) The transition from basic neural networks to sophisticated CNN has enabled remarkable advancements in image recognition, which are directly applicable to analyzing seismic data. The U-Net 3D model, with its innovative architecture, exemplifies this progress by providing a method for detailed and accurate fault detection with reduced manual interpretation bias. 2) The U-Net 3D model has demonstrated its superiority over traditional fault identification methods in several key areas: it has enhanced interpretation accuracy, increased operational efficiency, and reduced the subjectivity of manual methods. 3) Despite these achievements, challenges such as the need for effective data preprocessing, acquisition of high-quality annotated datasets, and achieving model generalization across different geological conditions remain. Future research should therefore focus on developing more complex network architectures and innovative training strategies to refine fault identification performance further. Our findings confirm the transformative potential of deep learning, particularly CNN like the U-Net 3D model, in geosciences, advocating for its broader integration to revolutionize geological exploration and seismic analysis.展开更多
Recent advances in hydrocarbon exploration have been made in the Member Deng-2 marginal microbial mound-bank complex reservoirs of the Dengying Formation in the western Sichuan Basin, SW China,where the depositional p...Recent advances in hydrocarbon exploration have been made in the Member Deng-2 marginal microbial mound-bank complex reservoirs of the Dengying Formation in the western Sichuan Basin, SW China,where the depositional process is regarded confusing. The microfacies, construction types, and depositional model of the Member Deng-2 marginal microbial mound-bank complex have been investigated using unmanned aerial vehicle photography, outcrop section investigation, thin section identification,and seismic reflections in the southwestern Sichuan Basin. The microbialite lithologic textures in this region include thrombolite, dendrolite, stromatolite, fenestral stromatolite, spongiostromata stone,oncolite, aggregated grainstone, and botryoidal grapestone. Based on the comprehensive analysis of“depositional fabrics-lithology-microfacies”, an association between a fore mound, mound framework,and back mound subfacies has been proposed based on water depth, current direction, energy level and lithologic assemblages. The microfacies of the mound base, mound core, mound flank, mound cap, and mound flat could be recognized among the mound framework subfacies. Two construction types of marginal microbial mound-bank complex have been determined based on deposition location, mound scale, migration direction, and sedimentary facies association. Type Jinkouhe microbial mound constructions(TJMMCs) develop along the windward margin owing to their proximity to the seaward subfacies fore mound, with a northeastwardly migrated microbial mound on top of the mud mound,exhibiting the characteristics of large-sized mounds and small-sized banks in the surrounding area. Type E'bian microbial mound constructions(TEMMCs) primarily occur on the leeward margin, resulting from the presence of onshore back mound subfacies, with the smaller southwestward migrated microbial mounds existing on a thicker microbial flat. The platform margin microbial mound depositional model can be correlated with certain lateral comparison profile and seismic reflection structures in the 2D seismic section, which can provide references for future worldwide exploration. Microbial mounds with larger buildups and thicker vertical reservoirs are typically targeted on the windward margin, while small-sized microbial mounds and flats with better lateral connections are typically focused on the leeward margin.展开更多
Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electr...Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electron microscopy analyses,it was found that the spot defects were caused by the residual oxide layer on the surface of the cold-rolled Fe-36%Ni alloy strip after hydrogen annealing.By properly increasing the grinding amount of the blank before cold rolling to remove the oxide layer,the spot defects on the surface of the cold-rolled strip were effectively eliminated,and the surface quality of the product was ensured.展开更多
Artificial intelligence (AI) has become increasingly important in geothermal exploration,significantly improving the efficiency of resource identification.This review examines current AI applications,focusing on the a...Artificial intelligence (AI) has become increasingly important in geothermal exploration,significantly improving the efficiency of resource identification.This review examines current AI applications,focusing on the algorithms used,the challenges addressed,and the opportunities created.In addition,the review highlights the growth of machine learning applications in geothermal exploration over the past decade,demonstrating how AI has improved the analysis of subsurface data to identify potential resources.AI techniques such as neural networks,support vector machines,and decision trees are used to estimate subsurface temperatures,predict rock and fluid properties,and identify optimal drilling locations.In particular,neural networks are the most widely used technique,further contributing to improved exploration efficiency.However,the widespread adoption of AI in geothermal exploration is hindered by challenges,such as data accessibility,data quality,and the need for tailored data science training for industry professionals.Furthermore,the review emphasizes the importance of data engineering methodologies,data scaling,and standardization to enable the development of accurate and generalizable AI models for geothermal exploration.It is concluded that the integration of AI into geothermal exploration holds great promise for accelerating the development of geothermal energy resources.By effectively addressing key challenges and leveraging AI technologies,the geothermal industry can unlock cost‐effective and sustainable power generation opportunities.展开更多
Integrated geophysical technology is a necessary and effective means for geothermal exploration.However,integration of geophysical technology for large‐scale surveys with those for geothermal reservoir localization i...Integrated geophysical technology is a necessary and effective means for geothermal exploration.However,integration of geophysical technology for large‐scale surveys with those for geothermal reservoir localization is still in development.This study used the controlled source audio‐frequency magnetotelluric method technology for large‐scale exploration to obtain underground electrical structure information and micromotion detection technology to obtain underground wave velocity structure information.The combination of two detection technologies was used for local identification of geothermal reservoirs.Further,auxiliary correction and inversion constraint were implemented through the audio magnetotelluric sounding technology for maximum authenticity restoration of the near‐and transition‐field data.Through these technology improvements,a geothermal geological model was established for the Binhai County of Jiangsu Province in China and potential geothermal well locations were identified.On this basis,a geothermal well was drilled nearly 3000m deep,with a daily water volume of over 2000m3/day and a geothermal water temperature of 51°C at the well head.It is found that predictions using the above integrated geophysical exploration technology are in good agreement with the well geological formation data.This integrated geophysical technology can be effectively applied for geothermal exploration with high precision and reliability.展开更多
The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in eff...The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology.展开更多
In the era of digital empowerment,the digital reform of higher vocational courses has become an inevitable trend.To explore professional curriculum reform,this study takes the“Class Management”course in the primary ...In the era of digital empowerment,the digital reform of higher vocational courses has become an inevitable trend.To explore professional curriculum reform,this study takes the“Class Management”course in the primary education major of higher vocational teachers as the research object,analyzes the importance of digital empowerment to curriculum reform,and discusses the teaching of the“Class Management”course new model and content reform plan.Digital technology empowering traditional courses is a new trend,which is both an opportunity and a challenge.This study aims to explore the application of digital technology in courses and provide certain guidelines for curriculum reform in the field of education.展开更多
With the acceleration of the social information process,information awareness and information skills have become the basic qualities of every citizen.The establishment of the training mechanism for scientific and tech...With the acceleration of the social information process,information awareness and information skills have become the basic qualities of every citizen.The establishment of the training mechanism for scientific and technological innovation talents from the beginning of higher education is insufficient to meet the needs of the development of the times.It is imperative to improve the training of information technology innovation talents and explore a new training model.This paper describes the general situation of the development of education in the field of information technology from a domestic and international perspective.It then analyzes the existing problems,explores new exploration models and implementation suggestions,and puts forward prospects at the end of the paper.展开更多
This study aims to address the problems existing in the ideological and political education of postgraduate students,and combines the implementation of the mentor responsibility system to explore the role orientation,...This study aims to address the problems existing in the ideological and political education of postgraduate students,and combines the implementation of the mentor responsibility system to explore the role orientation,work content,and practical effects of mentors in the ideological and political education of postgraduate students.Through questionnaire surveys,interviews,and other research methods,the current situation of ideological and political education of postgraduate students under the mentor responsibility system is analyzed,and corresponding optimization strategies are proposed.展开更多
With the acceleration of economic development and globalization and the rapid development of China’s foreign economy,the position of English education in higher vocational education has become increasingly prominent....With the acceleration of economic development and globalization and the rapid development of China’s foreign economy,the position of English education in higher vocational education has become increasingly prominent.Particularly in the multi-ethnic and multi-cultural areas of Guangxi Zhuang Autonomous Region,higher vocational education undertakes the responsibility of talent export for the construction of the China-ASEAN foreign trade exchange platform.However,the current phenomena and problems existing in higher vocational English education in Guangxi need to be deeply discussed and solved.Therefore,this paper discusses the development ideas of English education mode in Guangxi higher vocational education and studies the feasibility suggestions,in order to provide a reference for the future development of higher vocational English education in Guangxi.展开更多
In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice re...In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice residents(commonly referred to as general resident training)is an unavoidable trend in the teaching field.Based on the actual situation of our unit at The First Affiliated Hospital of Xi’an Medical University,this paper emphasizes the necessity of incorporating ideological and political education into the general resident training curriculum,despite the absence of pertinent practical experience in how to effectively incorporate such courses into comprehensive residential training.In our hospital,we must assess the ideological and political education in the curriculum of general resident training,proposing a scientific,reasonable ideological and political education concept system for general practice courses,integrating ideological and political education with general practice resident training,and strengthening the team of ideological and political education physicians to teach them to carry out such education,this would foster enthusiasm and initiative.Strengthening admission education and training for general practice resident training,as well as regularly hosting symposiums to share ideas and understand the mission of doctors can provide effective experience for ideological and political education in general resident training courses.展开更多
Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosph...Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)aims to capture two-dimensional(2-D)images of the Earth’s magnetosheath by using soft X-ray imaging.However,the observed 2-D images are affected by many noise factors,destroying the contained information,which is not conducive to the subsequent reconstruction of the three-dimensional(3-D)structure of the magnetopause.The analysis of SXI-simulated observation images shows that such damage cannot be evaluated with traditional restoration models.This makes it difficult to establish the mapping relationship between SXIsimulated observation images and target images by using mathematical models.We propose an image restoration algorithm for SXIsimulated observation images that can recover large-scale structure information on the magnetosphere.The idea is to train a patch estimator by selecting noise–clean patch pairs with the same distribution through the Classification–Expectation Maximization algorithm to achieve the restoration estimation of the SXI-simulated observation image,whose mapping relationship with the target image is established by the patch estimator.The Classification–Expectation Maximization algorithm is used to select multiple patch clusters with the same distribution and then train different patch estimators so as to improve the accuracy of the estimator.Experimental results showed that our image restoration algorithm is superior to other classical image restoration algorithms in the SXI-simulated observation image restoration task,according to the peak signal-to-noise ratio and structural similarity.The restoration results of SXI-simulated observation images are used in the tangent fitting approach and the computed tomography approach toward magnetospheric reconstruction techniques,significantly improving the reconstruction results.Hence,the proposed technology may be feasible for processing SXI-simulated observation images.展开更多
To explore the geological characteristics and exploration potential of the Carboniferous Benxi Formation coal rock gas in the Ordos Basin,this paper presents a systematic research on the coal rock distribution,coal ro...To explore the geological characteristics and exploration potential of the Carboniferous Benxi Formation coal rock gas in the Ordos Basin,this paper presents a systematic research on the coal rock distribution,coal rock reservoirs,coal rock quality,and coal rock gas features,resources and enrichment.Coal rock gas is a high-quality resource distinct from coalbed methane,and it has unique features in terms of burial depth,gas source,reservoir,gas content,and carbon isotopic composition.The Benxi Formation coal rocks cover an area of 16×104km^(2),with thicknesses ranging from 2 m to 25 m,primarily consisting of bright and semi-bright coals with primitive structures and low volatile and ash contents,indicating a good coal quality.The medium-to-high rank coal rocks have the total organic carbon(TOC)content ranging from 33.49%to 86.11%,averaging75.16%.They have a high degree of thermal evolution(Roof 1.2%-2.8%),and a high gas-generating capacity.They also have high stable carbon isotopic values(δ13C1of-37.6‰to-16‰;δ13C2of-21.7‰to-14.3‰).Deep coal rocks develop matrix pores such as gas bubble pores,organic pores,and inorganic mineral pores,which,together with cleats and fractures,form good reservoir spaces.The coal rock reservoirs exhibit the porosity of 0.54%-10.67%(averaging 5.42%)and the permeability of(0.001-14.600)×10^(-3)μm^(2)(averaging 2.32×10^(-3)μm^(2)).Vertically,there are five types of coal rock gas accumulation and dissipation combinations,among which the coal rock-mudstone gas accumulation combination and the coal rock-limestone gas accumulation combination are the most important,with good sealing conditions and high peak values of total hydrocarbon in gas logging.A model of coal rock gas accumulation has been constructed,which includes widespread distribution of medium-to-high rank coal rocks continually generating gas,matrix pores and cleats/fractures in coal rocks acting as large-scale reservoir spaces,tight cap rocks providing sealing,source-reservoir integration,and five types of efficient enrichment patterns(lateral pinchout complex,lenses,low-amplitude structures,nose-like structures,and lithologically self-sealing).According to the geological characteristics of coal rock gas,the Benxi Formation is divided into 8 plays,and the estimated coal rock gas resources with a buried depth of more than 2000 m are more than 12.33×10^(12)m^(3).The above understandings guide the deployment of risk exploration.Two wells drilled accordingly obtained an industrial gas flow,driving the further deployment of exploratory and appraisal wells.Substantial breakthroughs have been achieved,with the possible reserves over a trillion cubic meters and the proved reserves over a hundred billion cubic meters,which is of great significance for the reserves increase and efficient development of natural gas in China.展开更多
基金supported in part by the Huxiang Youth Talent Support Program(No.2020RC3030)in part by the Foundation of State Key Laboratory of Pulsed Power Laser Technology(Nos.SKL2021ZR02 and SKL2021KF05)。
文摘To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.
基金Supported by the National Natural Science Foundation of China(41802177,42272188)PetroChina Basic Technology Research and Development Project(2021DJ0206,2022DJ0507)Research Fund of PetroChina Basic Scientific Research and Strategic Reserve Technology(2020D-5008-04).
文摘Based on the organic geochemical data and the molecular and stable carbon isotopic compositions of natural gas of the Lower Permian Fengcheng Formation in the western Central Depression of Junggar Basin,combined with sedimentary environment analysis and hydrocarbon-generating simulation,the gas-generating potential of the Fengcheng source rock is evaluated,the distribution of large-scale effective source kitchen is described,the genetic types of natural gas are clarified,and four types of favorable exploration targets are selected.The results show that:(1)The Fengcheng Formation is a set of oil-prone source rocks,and the retained liquid hydrocarbon is conducive to late cracking into gas,with characteristics of high gas-generating potential and late accumulation;(2)The maximum thickness of Fengcheng source rock reaches 900 m.The source rock has entered the main gas-generating stage in Penyijingxi and Shawan sags,and the area with gas-generating intensity greater than 20×10^(8) m^(3)/km^(2) is approximately 6500 km^(2).(3)Around the western Central Depression,highly mature oil-type gas with light carbon isotope composition was identified to be derived from the Fengcheng source rocks mainly,while the rest was coal-derived gas from the Carboniferous source rock;(4)Four types of favorable exploration targets with exploration potential were developed in the western Central Depression which are structural traps neighboring to the source,stratigraphic traps neighboring to the source,shale-gas type within the source,and structural traps within the source.Great attention should be paid to these targets.
文摘The year of 2024 marks the 50th anniversary of the publication of Petroleum Exploration and Development.For half a century,Petroleum Exploration and Development has been committed to disseminating petroleum technology,witnessing and recording the glorious journey of China's petroleum industry from being weak to becoming strong.The journal has also become a bright banner in China's petroleum technology industry.
基金financially supported by the CNPC Prospective Basic Science and Technology Special Project(2023ZZ08)the Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(2020CX050103)。
文摘Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated.
基金Supported by the National Natural Science Foundation of China(No.42106080)the Laboratory for Marine Geology+2 种基金China Ocean Mineral Resources R&D Association Project(No.DY135-S2-2-03)the Natural Science Foundation of Shandong Province(No.ZR2020QD074)the Talents Research Start-up Funding Project of Ludong University。
文摘Six hydrothermal sediment samples were collected from the Xunmei and Tongguan hydrothermal fields along the southern Mid-Atlantic Ridge during the China Ocean Cruise DY46 in 2017.Sulfides and oxides in the samples were separated,and Cu and Zn isotope compositions were analyzed.Results show that the ranges ofδ^(65)Cu values of the bulk sediments,sulfides,and oxides were 0.36‰-2.46‰,-0.21‰-1.10‰,and 0.68‰-1.52‰,respectively.Theδ^(65)Cu values of sulfides in four samples(46II-14,46II-30,46III-06,and 46II-09)were relatively low(-0.21‰-0.50‰),corresponding to theδ^(65)Cu values of sulfides from inactive old hydrothermal chimneys in northern Mid-Atlantic Ridge(n MAR),suggesting that the sulfides in the sediments were originated from collapsed dead chimney mainly.While theδ^(65)Cu values of the other two samples(46III-02 and 46III-08)were relatively high(1.10‰-0.96‰),corresponding to theδ^(65)Cu values for active hydrothermal chimneys sulfides in n MAR,which indicated that the sulfides in these two samples might mainly come from sulfide particles settled from active hydrothermal plume.Because of the high density of sulfide particles,they tended to settle near the hydrothermal vents first.Therefore,highδ^(65)Cu values of sulfides in 46III-02 and 46III-08 implied that undiscovered active hydrothermal vents near the sampling positions of 46III-02 in the Xunmei hydrothermal field and 46III-08 in the Tongguan hydrothermal field.Theδ^(66)Zn values of hydrothermal sediments and sulfides ranged 0.11‰-0.43‰and 0.29‰-0.67‰,respectively.In the four samples from the Xunmei hydrothermal field,a positive correlation was found between the distance of the sampling position from sulfide mineralized spot and the Zn isotopic ratio,showing that the greater the distance from the mineralized spot,the heavier the Zn isotope composition as seen in two samples(46II-30 and 46II-14)of the Xunmei-3 spot.This result aligned with the findings of Wilkinson et al.(2005)and Baumgartner et al.(2023),suggesting that the lower the Zn isotope composition,the closer it is to the hydrothermal vent.However,in the Xunmei hydrothermal field,the Zn isotope composition in the other two samples(46III-02and 46III-06)showed the opposite trend.This indicated that there might be an active hydrothermal vent near the sampling location of sample 46III-02.This observation aligned with the Cu isotope analysis results.This study showed that Cu-Zn isotopes are good indicators for understanding the formation mechanisms of hydrothermal sediments and for locating active hydrothermal vents.
基金Counting at GTL funded by the Shenzhen Zhilan FoundationAlashan SEE Ecological Association+1 种基金Beijing Xianfeng FoundationCounting at PXL was funded by the Alashan SEE Chongqing Center
文摘Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful migration.While age and experience have been identified as key factor influencing migration route selection among soaring raptors in the African-Eurasian Flyway,how they shape the migration route of soaring raptors in East Asia is still largely unknown.In this study,we investigated potential variations in the routes and timing in autumn migration of juvenile and older soaring birds,using count data of Greater Spotted Eagles(Clanga clanga)from two coastal sites and two inland sites in China.From 2020 to 2023,we recorded a total of 340 individuals,with the highest site averaging over 90 individuals per autumn,making it one of the world’s top single-season counts and thus a globally important site for this species.We found that 82% and 61% records from coastal sites were juveniles,significantly higher than inland sites(15% and 24%).Juveniles at all four sites exhibited markedly earlier median passage time than non-juveniles,with brief overlapping in their main migration periods.Both coastal sites are located on the tip of peninsulas stretching southwest,requiring long overwater flights if crossing the Bohai Bay or Beibu Gulf,which would be energetically demanding and increase mortality risk.Experienced individuals may have learned to avoid such terrain and subsequent detour,while juveniles are more prone to enter these peninsulas due to lack of experience and opportunities for social learning,or following other raptor species that are more capable of powered flight.Our findings highlight the importance of age and experience in migration route selection of large soaring birds.
文摘Production performance of the Wufeng-Longmaxi shales varies significantly among Fuling,Weirong,and Wulong fields in the Sichuan Basin.Total organic carbon(TOC)content,mineralogy,and organic matter(OM)pore characteristics are investigated to identify key factors governing sweet spots.Siliceous shales with good preservation conditions in the Fuling Field exhibit large thickness,high TOC content and thin-section porosity(TSP),and well-developed OM macropores,thus high initial production and estimated ultimate recovery(EUR).Thin carbonate-containing siliceous shales with good preservation conditions in the Weirong Field feature medium-to-high TOC and well-developed OM macropores but low TSP,leading to high initial production but low EUR.Siliceous shales with poor preservation conditions in the Wulong Field are characterized by large thickness,high TOC,low TSP and poorly-developed OM macropores,causing low initial production and EUR.Both sedimentary and preservation conditions are intrinsic decisive factors of sweet spots,as they control the mineral composition,TOC,and OM macropore development.Deep-water shales in transgressive systems tracts(TSTs)exhibit better-developed OM macropores and greater TOC compared to highstand systems tracts(HSTs).OM macropores are most prevalent in siliceous shales,followed by carbonate-containing siliceous shales and then argillaceous shales.Furthermore,good preservation conditions are conducive to retain OM macropores with low pore aspect ratio(PAR).Comparison among the three fields shows that high-TOC silicious shales with good preservation conditions are the highest in TSP and EUR.Therefore,organic richness,lithofacies,and preservation conditions are the major factors which determine OM pore development,governing the sweet spots of the Wufeng-Longmaxi shales.
文摘Deep learning, especially through convolutional neural networks (CNN) such as the U-Net 3D model, has revolutionized fault identification from seismic data, representing a significant leap over traditional methods. Our review traces the evolution of CNN, emphasizing the adaptation and capabilities of the U-Net 3D model in automating seismic fault delineation with unprecedented accuracy. We find: 1) The transition from basic neural networks to sophisticated CNN has enabled remarkable advancements in image recognition, which are directly applicable to analyzing seismic data. The U-Net 3D model, with its innovative architecture, exemplifies this progress by providing a method for detailed and accurate fault detection with reduced manual interpretation bias. 2) The U-Net 3D model has demonstrated its superiority over traditional fault identification methods in several key areas: it has enhanced interpretation accuracy, increased operational efficiency, and reduced the subjectivity of manual methods. 3) Despite these achievements, challenges such as the need for effective data preprocessing, acquisition of high-quality annotated datasets, and achieving model generalization across different geological conditions remain. Future research should therefore focus on developing more complex network architectures and innovative training strategies to refine fault identification performance further. Our findings confirm the transformative potential of deep learning, particularly CNN like the U-Net 3D model, in geosciences, advocating for its broader integration to revolutionize geological exploration and seismic analysis.
基金jointly funded by projects supported by the National Natural Science Foundation of China(Grant No.41872150)the Joint Funds of the National Natural Science Foundation of China(Grant No.U19B6003)Major Scientific and Technological Projects of CNPC during the 13th five-year plan(No.2019A-02-10)。
文摘Recent advances in hydrocarbon exploration have been made in the Member Deng-2 marginal microbial mound-bank complex reservoirs of the Dengying Formation in the western Sichuan Basin, SW China,where the depositional process is regarded confusing. The microfacies, construction types, and depositional model of the Member Deng-2 marginal microbial mound-bank complex have been investigated using unmanned aerial vehicle photography, outcrop section investigation, thin section identification,and seismic reflections in the southwestern Sichuan Basin. The microbialite lithologic textures in this region include thrombolite, dendrolite, stromatolite, fenestral stromatolite, spongiostromata stone,oncolite, aggregated grainstone, and botryoidal grapestone. Based on the comprehensive analysis of“depositional fabrics-lithology-microfacies”, an association between a fore mound, mound framework,and back mound subfacies has been proposed based on water depth, current direction, energy level and lithologic assemblages. The microfacies of the mound base, mound core, mound flank, mound cap, and mound flat could be recognized among the mound framework subfacies. Two construction types of marginal microbial mound-bank complex have been determined based on deposition location, mound scale, migration direction, and sedimentary facies association. Type Jinkouhe microbial mound constructions(TJMMCs) develop along the windward margin owing to their proximity to the seaward subfacies fore mound, with a northeastwardly migrated microbial mound on top of the mud mound,exhibiting the characteristics of large-sized mounds and small-sized banks in the surrounding area. Type E'bian microbial mound constructions(TEMMCs) primarily occur on the leeward margin, resulting from the presence of onshore back mound subfacies, with the smaller southwestward migrated microbial mounds existing on a thicker microbial flat. The platform margin microbial mound depositional model can be correlated with certain lateral comparison profile and seismic reflection structures in the 2D seismic section, which can provide references for future worldwide exploration. Microbial mounds with larger buildups and thicker vertical reservoirs are typically targeted on the windward margin, while small-sized microbial mounds and flats with better lateral connections are typically focused on the leeward margin.
文摘Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electron microscopy analyses,it was found that the spot defects were caused by the residual oxide layer on the surface of the cold-rolled Fe-36%Ni alloy strip after hydrogen annealing.By properly increasing the grinding amount of the blank before cold rolling to remove the oxide layer,the spot defects on the surface of the cold-rolled strip were effectively eliminated,and the surface quality of the product was ensured.
文摘Artificial intelligence (AI) has become increasingly important in geothermal exploration,significantly improving the efficiency of resource identification.This review examines current AI applications,focusing on the algorithms used,the challenges addressed,and the opportunities created.In addition,the review highlights the growth of machine learning applications in geothermal exploration over the past decade,demonstrating how AI has improved the analysis of subsurface data to identify potential resources.AI techniques such as neural networks,support vector machines,and decision trees are used to estimate subsurface temperatures,predict rock and fluid properties,and identify optimal drilling locations.In particular,neural networks are the most widely used technique,further contributing to improved exploration efficiency.However,the widespread adoption of AI in geothermal exploration is hindered by challenges,such as data accessibility,data quality,and the need for tailored data science training for industry professionals.Furthermore,the review emphasizes the importance of data engineering methodologies,data scaling,and standardization to enable the development of accurate and generalizable AI models for geothermal exploration.It is concluded that the integration of AI into geothermal exploration holds great promise for accelerating the development of geothermal energy resources.By effectively addressing key challenges and leveraging AI technologies,the geothermal industry can unlock cost‐effective and sustainable power generation opportunities.
基金Geological and Mineral Resources Survey of Metallogenic Belt in the Middle and Lower Reaches of Yangtze River,Grant/Award Number:1212011220540Jiangsu 1:50000 Dingsanwei,Kaishan Island,Yangqiao,Chenjiagang,New Huaihe Estuary,Xiangshui Estuary,Dayou,Xiaojie,DayuJian District,Grant/Award Numbers:Base[2012]02‐014‐009,Base[2013]01‐019‐002,Base[2014]01‐021‐003。
文摘Integrated geophysical technology is a necessary and effective means for geothermal exploration.However,integration of geophysical technology for large‐scale surveys with those for geothermal reservoir localization is still in development.This study used the controlled source audio‐frequency magnetotelluric method technology for large‐scale exploration to obtain underground electrical structure information and micromotion detection technology to obtain underground wave velocity structure information.The combination of two detection technologies was used for local identification of geothermal reservoirs.Further,auxiliary correction and inversion constraint were implemented through the audio magnetotelluric sounding technology for maximum authenticity restoration of the near‐and transition‐field data.Through these technology improvements,a geothermal geological model was established for the Binhai County of Jiangsu Province in China and potential geothermal well locations were identified.On this basis,a geothermal well was drilled nearly 3000m deep,with a daily water volume of over 2000m3/day and a geothermal water temperature of 51°C at the well head.It is found that predictions using the above integrated geophysical exploration technology are in good agreement with the well geological formation data.This integrated geophysical technology can be effectively applied for geothermal exploration with high precision and reliability.
基金Funded by the“Investigation and Evaluation of the Hot Dry Rock Resources in the Guide-Dalianhai Area of the Gonghe Basin,Qinghai”(DD20211336,DD20211337,DD20211338)“Hot Dry Rock Resources Exploration and Production Demonstration Project”(DD20230018)of the China Geological Survey。
文摘The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology.
文摘In the era of digital empowerment,the digital reform of higher vocational courses has become an inevitable trend.To explore professional curriculum reform,this study takes the“Class Management”course in the primary education major of higher vocational teachers as the research object,analyzes the importance of digital empowerment to curriculum reform,and discusses the teaching of the“Class Management”course new model and content reform plan.Digital technology empowering traditional courses is a new trend,which is both an opportunity and a challenge.This study aims to explore the application of digital technology in courses and provide certain guidelines for curriculum reform in the field of education.
文摘With the acceleration of the social information process,information awareness and information skills have become the basic qualities of every citizen.The establishment of the training mechanism for scientific and technological innovation talents from the beginning of higher education is insufficient to meet the needs of the development of the times.It is imperative to improve the training of information technology innovation talents and explore a new training model.This paper describes the general situation of the development of education in the field of information technology from a domestic and international perspective.It then analyzes the existing problems,explores new exploration models and implementation suggestions,and puts forward prospects at the end of the paper.
基金Chang’an University Graduate Student Ideological and Political Education Innovation Demonstration Pro-ject(No.300103740013)Education Science Research Project of China Association of Transportation Education(No.JT2022YB222)+1 种基金Research Project on Education and Teaching Reform at Chang’an Dublin International College of Transpor-tation at Chang’an University(No.CDIC-JG-200301)Construction Project for Continuous Improvement of National First-Class Courses on Interchangeability and Measurement Technology(No.300103230119)。
文摘This study aims to address the problems existing in the ideological and political education of postgraduate students,and combines the implementation of the mentor responsibility system to explore the role orientation,work content,and practical effects of mentors in the ideological and political education of postgraduate students.Through questionnaire surveys,interviews,and other research methods,the current situation of ideological and political education of postgraduate students under the mentor responsibility system is analyzed,and corresponding optimization strategies are proposed.
基金2022 Guangxi Education Science Planning Project“The Inheritance and Discussion of National Culture in the Internationalization of Higher Vocational Education under the Background of the New Era”(2022ZJY3095)。
文摘With the acceleration of economic development and globalization and the rapid development of China’s foreign economy,the position of English education in higher vocational education has become increasingly prominent.Particularly in the multi-ethnic and multi-cultural areas of Guangxi Zhuang Autonomous Region,higher vocational education undertakes the responsibility of talent export for the construction of the China-ASEAN foreign trade exchange platform.However,the current phenomena and problems existing in higher vocational English education in Guangxi need to be deeply discussed and solved.Therefore,this paper discusses the development ideas of English education mode in Guangxi higher vocational education and studies the feasibility suggestions,in order to provide a reference for the future development of higher vocational English education in Guangxi.
文摘In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice residents(commonly referred to as general resident training)is an unavoidable trend in the teaching field.Based on the actual situation of our unit at The First Affiliated Hospital of Xi’an Medical University,this paper emphasizes the necessity of incorporating ideological and political education into the general resident training curriculum,despite the absence of pertinent practical experience in how to effectively incorporate such courses into comprehensive residential training.In our hospital,we must assess the ideological and political education in the curriculum of general resident training,proposing a scientific,reasonable ideological and political education concept system for general practice courses,integrating ideological and political education with general practice resident training,and strengthening the team of ideological and political education physicians to teach them to carry out such education,this would foster enthusiasm and initiative.Strengthening admission education and training for general practice resident training,as well as regularly hosting symposiums to share ideas and understand the mission of doctors can provide effective experience for ideological and political education in general resident training courses.
基金supported by the National Natural Science Foundation of China(Grant Nos.42322408,42188101,41974211,and 42074202)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDJ-SSW-JSC028)+1 种基金the Strategic Priority Program on Space Science,Chinese Academy of Sciences(Grant Nos.XDA15052500,XDA15350201,and XDA15014800)supported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.Y202045)。
文摘Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)aims to capture two-dimensional(2-D)images of the Earth’s magnetosheath by using soft X-ray imaging.However,the observed 2-D images are affected by many noise factors,destroying the contained information,which is not conducive to the subsequent reconstruction of the three-dimensional(3-D)structure of the magnetopause.The analysis of SXI-simulated observation images shows that such damage cannot be evaluated with traditional restoration models.This makes it difficult to establish the mapping relationship between SXIsimulated observation images and target images by using mathematical models.We propose an image restoration algorithm for SXIsimulated observation images that can recover large-scale structure information on the magnetosphere.The idea is to train a patch estimator by selecting noise–clean patch pairs with the same distribution through the Classification–Expectation Maximization algorithm to achieve the restoration estimation of the SXI-simulated observation image,whose mapping relationship with the target image is established by the patch estimator.The Classification–Expectation Maximization algorithm is used to select multiple patch clusters with the same distribution and then train different patch estimators so as to improve the accuracy of the estimator.Experimental results showed that our image restoration algorithm is superior to other classical image restoration algorithms in the SXI-simulated observation image restoration task,according to the peak signal-to-noise ratio and structural similarity.The restoration results of SXI-simulated observation images are used in the tangent fitting approach and the computed tomography approach toward magnetospheric reconstruction techniques,significantly improving the reconstruction results.Hence,the proposed technology may be feasible for processing SXI-simulated observation images.
基金Supported by the PetroChina Science and Technology Major Project(2023ZZ18-03)Changqing Oilfield Major Science and Technology Project(2023DZZ01)。
文摘To explore the geological characteristics and exploration potential of the Carboniferous Benxi Formation coal rock gas in the Ordos Basin,this paper presents a systematic research on the coal rock distribution,coal rock reservoirs,coal rock quality,and coal rock gas features,resources and enrichment.Coal rock gas is a high-quality resource distinct from coalbed methane,and it has unique features in terms of burial depth,gas source,reservoir,gas content,and carbon isotopic composition.The Benxi Formation coal rocks cover an area of 16×104km^(2),with thicknesses ranging from 2 m to 25 m,primarily consisting of bright and semi-bright coals with primitive structures and low volatile and ash contents,indicating a good coal quality.The medium-to-high rank coal rocks have the total organic carbon(TOC)content ranging from 33.49%to 86.11%,averaging75.16%.They have a high degree of thermal evolution(Roof 1.2%-2.8%),and a high gas-generating capacity.They also have high stable carbon isotopic values(δ13C1of-37.6‰to-16‰;δ13C2of-21.7‰to-14.3‰).Deep coal rocks develop matrix pores such as gas bubble pores,organic pores,and inorganic mineral pores,which,together with cleats and fractures,form good reservoir spaces.The coal rock reservoirs exhibit the porosity of 0.54%-10.67%(averaging 5.42%)and the permeability of(0.001-14.600)×10^(-3)μm^(2)(averaging 2.32×10^(-3)μm^(2)).Vertically,there are five types of coal rock gas accumulation and dissipation combinations,among which the coal rock-mudstone gas accumulation combination and the coal rock-limestone gas accumulation combination are the most important,with good sealing conditions and high peak values of total hydrocarbon in gas logging.A model of coal rock gas accumulation has been constructed,which includes widespread distribution of medium-to-high rank coal rocks continually generating gas,matrix pores and cleats/fractures in coal rocks acting as large-scale reservoir spaces,tight cap rocks providing sealing,source-reservoir integration,and five types of efficient enrichment patterns(lateral pinchout complex,lenses,low-amplitude structures,nose-like structures,and lithologically self-sealing).According to the geological characteristics of coal rock gas,the Benxi Formation is divided into 8 plays,and the estimated coal rock gas resources with a buried depth of more than 2000 m are more than 12.33×10^(12)m^(3).The above understandings guide the deployment of risk exploration.Two wells drilled accordingly obtained an industrial gas flow,driving the further deployment of exploratory and appraisal wells.Substantial breakthroughs have been achieved,with the possible reserves over a trillion cubic meters and the proved reserves over a hundred billion cubic meters,which is of great significance for the reserves increase and efficient development of natural gas in China.