检索结果-南通市图书馆

A new deep-reading look-ahead method in electromagnetic loggingwhile-drilling using the scattered electric field from magnetic dipole antennas

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2022年第1期19卷 180-188页

作者： Lei Wang shao-gui deng Guan-Bao Xie Shan-Jun Li Zhen-Guan Wu Yi-Ren Fan School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdaoShandong 266071China State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing100083China Beyond Bits Technoogy Inc.Houston78741USA

This paper presents a new deep-reading logging-while-drilling electromagnetic(EM)logging method to detect bed boundaries ahead of *** all existing EM logging approaches,the new method is based on the scattered electric field radiated by a magnetic dipole *** analyzing the characteristics of electric tensor responses in layered formations,optimal look-ahead electric component is *** selected scattered field contributes to a large portion of the total field and is strongly sensitive to the boundary *** measured voltage from the scattered electric component can be tens of times larger than that from the scattered magnetic fields and it attenuates ***,the detection capability improves significantly.A coaxial open-loop half-circle antenna is then proposed to measure the electric field in logging while drilling environment.A practical tool implementation equipped with two tilted close-loop antennas and two open-loop antennas is further developed for look-ahead *** results demonstrate that the detection depth of the new look-ahead tool can be up to 40 m under favorable *** with current look-ahead logging tools,the new method not only significantly shortens the tool size,but also can recognize the boundary position and azimuth.

关键词： Electromagnetic logging-while-drilling look-ahead Deep reading Scattered electric field Short spacing

Numerical simulation of high-resolution azimuthal resistivity laterolog response in fractured reservoirs

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2015年第2期12卷 252-263页

作者： shao-gui deng Li Li Zhi-Qiang Li Xu-Quan He Yi-Ren Fan School of Geosciences China University of Petroleum China Research Institute of Radiowave Propagation China Petroleum Southwest Oil and Gas Field Branch

The high-resolution azimuthal resistivity laterolog response in a fractured formation was numerically simulated using a three-dimensional finite element method. Simulation results show that the azimuthal resistivity is determined by fracture dipping as well as dipping direction, while the amplitude differences between deep and shallow laterolog resistivities are mainly controlled by the former. A linear relationship exists between the corrected apparent conductivities and fracture aperture. With the same fracture aperture, the deep and shallow laterolog resistivities present small values with negative separations for low-angle fractures, while azimuthal resistivities have large variations with positive separations for high-angle fractures that intersect the borehole. For dipping fractures, the variation of the azimuthal resistivity becomes larger when the fracture aperture increases. In addition, for high-angle fractures far from the borehole, a negative separation between the deep and shallow resistivities exists when fracture aperture is large as well as high resistivity contrast exists between bedrock and fracture fluid. The decreasing amplitude of dual laterolog resistivity can indicate the aperture of low-angle fractures, and the variation of the deep azimuthal resistivity can give information of the aperture of high-angle fractures and their position relative to the borehole.

关键词： High-resolution azimuthal resistivitylaterolog Fractured reservoir Fracture dipping angleFracture aperture. Fracture dipping direction

Detection performance and inversion processing of logging-while-drilling extra-deep azimuthal resistivity measurements

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2019年第5期16卷 1015-1027页

作者： Lei Wang shao-gui deng Pan Zhang Ying-Chang Cao Yi-Ren Fan Xi-Yong Yuan School of Geosciences China University of PetroleumQingdao 266580ShandongChina Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071ShandongChina CNPC Key Laboratory for Well Logging China University of PetroleumQingdao 266580ShandongChina

We present systematic investigations on the physics,detection performance and inversion of logging-while-drilling extradeep azimuthal resistivity measurements(EDARM).First,the definitions of EDRAM measurements are discussed,followed by the derivation of the attenuation and phase-shift geometrical factors to illustrate the relative contributions of formation units to the observed ***,a new definition of detection depth,which considers the uncertainty of inversion results caused by the data noise,is proposed to quantify the detection capability of ED ***,the B ayesian theory associated with Markov chain Monte Carlo sampling is introduced for fast processing of EDARM *** results show that ED ARM is capable of detecting the azimuth and distance of remote bed boundaries,and the detection capability increases with increasing spacing and resistivity *** EDARM tool can accommodate a large range of formation resistivity and is able to provide the resistivity anisotropy at arbitrary relative dipping *** addition,multiple bed boundaries and reservoir images near the borehole are readily obtained by using the Bayesian inversion.

关键词： Extra-deep azimuthal resistivity measurements(EDARM) Detection performance Inversion method Reservoir imaging Detection of multiple bed boundaries

Numerical simulation and dimension reduction analysis of electromagnetic logging while drilling of horizontal wells in complex structures

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2020年第3期17卷 645-657页

作者： Zhen-Guan Wu shao-gui deng Xu-Quan He Runren Zhang Yi-Ren Fan Xi-Yong Yuan Yi-Zhi Wu Qing Huo Liu School of Geosciences China University of PetroleumQingdao 266580ShandongChina Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071Shandong.China CNPC Key Laboratory for Well Logging China University of PetroleumQingdao 266580ShandongChina Research Institute of Exploration and Development PetroChina Southwest Oil and Gas Field CompanyChengdu 610041SichuanChina Duke University DurhamNC 27705USA

Electromagnetic logging while drilling(LWD)is one of the key technologies of the geosteering and formation evaluation for high-angle and horizontal *** this paper,we solve the dipole source-generated magnetic/electric fields in 2D formations efficiently by the 2.5D finite diff erence ***,by leveraging the field’s rapid attenuation in spectral domain,we propose truncated Gauss–Hermite quadrature,which is several tens of times faster than traditional inverse fast Fourier *** applying the algorithm to the LWD modeling under complex formations,e.g.,folds,fault and sandstone pinch-outs,we analyze the feasibility of the dimension reduction from 2D to *** the formations with smooth lateral changes,like folds,the simplified 1D model’s results agree well with the true responses,which indicate that the 1D simplification with sliding window is ***,for the formation structures with drastic rock properties changes and sharp boundaries,for instance,faults and sandstone pinch-outs,the simplified 1D model will lead to large errors and,therefore,2.5D algorithms should be applied to ensure the accuracy.

关键词： Complex formation structures Horizontal wells Electromagnetic logging while drilling 2.5D algorithm-Model simplification

Impact of human activities on the long-term change and seasonal variability of Ebinur Lake,Northwest China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第2期68卷 473-486页

作者： Haoxin deng Qiuhong TANG Zhidong ZHANG Xingcai LIU Gang ZHAO Shibo CUI Zhiping ZHANG Shuai shao Jianbao LIU Fahu CHEN Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China School of Geography Nanjing Normal UniversityNanjing 210023China Group of Alpine Paleoecology and Human Adaptation(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Inland lakes in arid Central Asia are particularly susceptible to the impact of climate change and human *** Lake,the largest salt inland lake in Xinjiang,Northwest China,has experienced rapid shrinkage,with human activities identified as the primary influencing ***,it remains unclear how human water use in different sectors,such as irrigation,husbandry,and industry,is responsible for the long-term change and seasonal variability of the lake area under changing *** study aims to address this knowledge gap by developing an integrated hydrological-socioeconomic-lake model that simulates the changes in the Ebinur Lake area during the period of 1950–*** simulated lake area changes under different model experiments were then compared with separate the impacts of climate change and human water use of different *** results indicate that climate change,irrigation,husbandry,and industry water uses have contributed+5%,-79%,-25%,and-1%of the long-term change in the lake area,*** climate change alone increasing the lake area,the increase in human water use has resulted in the persistent decline of Ebinur ***,husbandry water use emerges as a significant contributor to lake shrinkage,accounting for approximately one-third of the impact of ***,irrigation water use has contributed to the enhanced seasonal variability,as indicated by the difference between the maximum and minimum monthly lake area in a *** difference has increased from 120 km2in the 1950s to 183 km2in the 2010s.

关键词： Ebinur Lake Climate change Irrigation Seasonal variability Hydrological-socioeconomic-lake model

同方期刊数据库

The composition of magmatic-hydrothermal fluids and their related metal mineralization

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第1期68卷 208-225页

作者： Qihai SHU Jun deng State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences and ResourcesChina University of GeosciencesBeijing100083China Frontiers Science Center for Deep-time Digital Earth China University of GeosciencesBeijing100083China

Magmatic hydrothermal deposits are important sources of many bulk,precious,and rare metals,and have attracted interest from both academic and industrial ***,it is still unclear if the major enrichment of the ore-forming metals occurs in the parental magma source region,during the magma evolution,or after the fluid *** inclusions trapped in hydrothermal minerals crystallized in the early,high-temperature stage before metal precipitation record information close to that of the initially exsolved magmatic fluids,which are helpful in revealing whether the metals have been already significantly enriched prior to the hydrothermal *** this study,available compositional data of such early-stage fluid inclusions from magmatic hydrothermal systems globally have been *** results indicate that the concentrations of Cu,Sn,and W respectively from the Cu-,Sn-,and W-mineralized fluids are significantly higher than the hydrothermal systems that do not produce ores with the corresponding *** suggests that Cu,Sn,and W could have already been enriched in the magma source and/or magma evolution *** Mo concentrations show no difference between Mo-mineralized and Mobarren fluid systems,indicating no significant pre-enrichment in the source region or during the magma *** also implies that an efficient collection of Mo from a large volume of magmas is required to account for the formation of a large Mo *** all the hydrothermal fluids contain high concentrations of Fe and Zn-Pb,but only a few of them eventually form Fe or Zn-Pb deposits,reflecting an important role of the hydrothermal evolution process on the selective metal *** above results indicate that different metals are enriched in different stages of a magmatic hydrothermal system,and that the major roles played in the formation of a deposit vary with the metal *** addition to the metal concentrations in the orerelated magmas and fluids

关键词： Magmatic hydrothermal deposits Fluid inclusions LA-ICP-MS Metal enrichment Mineralization mechanism

Canopy structural heterogeneity drives α and β species-genetic diversity correlations in a Chinese subtropical forest

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2025年第1期47卷 106-114页

作者： Zhiliang Yao Xia Pan Xin Yang Xiaona shao Bin Wang Yun deng Zhiming Zhang Qiaoming Li Luxiang Lin CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesKunming 650223YunnanChina University of Chinese Academy of Sciences Beijing 100049China School of Ecology and Environment Hainan UniversityHaikou 570228HainanChina State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River Mountain Tai Forest Ecosystem Research Station of State Forestry and Grassland AdministrationForestry College of Shandong Agricultural UniversityTai'an 271018ShandongChina School of Ecology and Environmental Sciences&Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan UniversityKunming 650500YunnanChina National Forest Ecosystem Research Station at Xishuangbanna Mengla 666303YunnanChina

Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is ***,few studies have examined the role of canopy structural heterogeneity,which is a defining feature of forests,in shaping ***,we determine what factors contribute toα-andβ-species–genetic diversity correlations(i.e.,α-andβ-SGDCs)in a Chinese subtropical *** this purpose,we used neutral molecular markers to assess genetic variation in almost all adult individuals of the dominant tree species,Lithocarpus xylocarpus,across plots in the Ailaoshan National Natural *** also quantified microhabitat variation by quantifying canopy structure heterogeneity with airborne laser scanning on 201-ha subtropical forest *** found that speciesα-diversity was negatively correlated with geneticα-*** structural heterogeneity was positively correlated with speciesα-diversity but negatively correlated with geneticα-*** contrasting effects contributed to the formation of a negativeα-***,we found that canopy structural heterogeneity increases speciesα-diversity and decreases geneticα-diversity by reducing the population size of target ***β-diversity,in contrast,was positively correlated with geneticβ-*** in canopy structural heterogeneity between plots had non-linear parallel effects on the two levels ofβ-diversity,while geographic distance had a relatively weak effect onβ-*** study indicates that canopy structural heterogeneity simultaneously affects plot-level community species diversity and population genetic diversity,and species and genetic turnover across plots,thus drivingα-andβ-SGDCs.

关键词： Dominant species Forest structure LiDAR Lithocarpus xylocarpus Speciesegenetic diversity correlation Subtropical evergreen broad-leaved forest

A Cross-Multi-Domain Trust Assessment Authority Delegation Method Based on Automotive Industry Chain

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2025年第1期82卷 407-426页

作者： Binyong Li Liangming deng Jie Zhang Xianhui deng School of Cybersecurity(Xin Gu Industrial College) Chengdu University of Information TechnologyChengdu610225China Advanced Cryptography and System Security Key Laboratory of Sichuan Province Chengdu610225China SUGON Industrial Control and Security Center Chengdu610225China

To solve the challenges of connecting and coordinating multiple platforms in the automotive industry and to enhance collaboration among different participants,this research focuses on addressing the complex supply relationships in the automotive market,improving data sharing and interactions across various platforms,and achieving more detailed integration of data and *** propose a trust evaluation permission delegation method based on the automotive industry *** proposed method combines smart contracts with trust evaluation mechanisms,dynamically calculating the trust value of users based on the historical behavior of the delegated entity,network environment,and other factors to avoid malicious node attacks during the permission delegation *** also introduce strict control over the cross-domain permission granting and revocation mechanisms to manage the delegation path,prevent information leakage caused by malicious node interception,and effectively protect data integrity and *** analysis shows that this method meets the realtime requirements of collaborative interaction in the automotive industry chain and provides a feasible solution to permission delegation issues in the automotive industry chain,offering dynamic flexibility in authorization and scalability compared to most existing solutions.

关键词： Automotive industry chain cross-domain access block chain delegate authority trust assessment

Reduction of thermal stratification due to global warming in winter and spring

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2025年第1期43卷 1-15页

作者： Jie LIU Jianming deng Xiangming TANG State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China School of Geography and Ocean Science Nanjing UniversityNanjing 210023China

Global warming has been reported to enhance thermal stratification and decrease the mixlayer depth(MLD)in waters due to higher surface water temperatures,especially in *** studies were conducted for individual cases or specific *** present,there is a lack of global assessments on the influence of climate warming in different seasons on thermal *** ECMWF Reanalysis v5(ERA5)dataset was used to estimate the variability of water body mixing and its drivers in different seasons and *** indicate that global warming could enhance thermal stratification and decrease the MLD globally in *** speed was the primary driver of MLD changes,followed by ***,ice melt due to global warming enhanced the mixing in icecovered waters in the Northern Hemisphere,and early ice melt led to early *** depth was the primary driver of MLD changes in the Northern Hemisphere due to delayed ice formation and earlier melting,while wind speed was the primary driver in other regions or during ice-free *** enhanced mixing due to earlier ice melt out in late winter and early spring could promote water circulation and nutrient turnover,and replenish dissolved oxygen in deep water,thereby promoting the maximum biomass of cyanobacteria and advance harmful algal blooms.

关键词： global warming mix-layer depth(MLD) thermal stratification ice depth ECMWF Reanalysis v5(ERA5)dataset