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Fracture geometry and breakdown pressure of radial borehole fracturing in multiple layers

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Petroleum Science 2024年第1期21卷 430-444页

作者： yu-Ning Yong Zhao-Quan Guo Shou-Ceng Tian Lu-Yao ma Tian-yu Wang mao Sheng National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Beijing Petroleum machinery Company Limited CNPC Engineering Technology R&D Company LimitedBeijing102206China Smart Energy Co. LtdChina Xiongan GroupXiong’an New Area071000HebeiChina

Radial borehole fracturing that combines radial boreholes with hydraulic fracturing is anticipated to improve the output of tight oil and gas *** paper aims to investigate fracture propagation and pressure characteristics of radial borehole fracturing in multiple layers.A series of laboratory experiments with artificial rock samples(395 mm×395 mm×395 mm)was conducted using a true triaxial fracturing *** crucial factors corresponding to the vertical distance of adjacent radial borehole layers(vertical distance),the azimuth and diameter of the radial borehole are *** results show that radial borehole fracturing in multiple layers generates diverse fracture *** types of fractures are identified based on the connectivity between hydraulic fractures and radial *** vertical distance significantly influences fracture propagation perpendicular to the radial borehole *** increase in the vertical distance impedes fracture connection across multiple radial borehole layers and reduces the fracture propagation distance along the radial borehole *** azimuth also influences fracture propagation along the radial borehole *** the azimuth reduces the guiding ability of radial boreholes,which makes the fracture quickly curve to the maximum horizontal stress *** breakdown pressure correlates with diverse fracture geometries *** the fractures connect multi-layer radial boreholes,increasing the vertical distance decreases the breakdown *** the azimuth and increasing the diameter also decrease the breakdown *** extrusion force exists between the adjacent fractures generated in radial boreholes in multiple rows,which plays a crucial role in enhancing the guiding ability of radial boreholes and results in higher breakdown *** research provides valuable theoretical insights for the field application of radial borehole fracturing technology in tight oil and g

关键词： Multi-layer radial boreholes Hydraulic fracturing Fracture propagation Pressure characteristic

Paleogene transgression process and environmental evolution in the deepwater area of the Baiyun Depression in the northern South China Sea

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Acta Oceanologica Sinica 2024年第4期43卷 15-24页

作者： Peijun Qiao yuchi Cui Qiong ma Qiang yu Lei Shao State Key Laboratory of marine Geology Tongji UniversityShanghai 200092China CNOOC Energy Technology&Services-Drilling&Production Co. CNOOC Central Laboratory Shenzhen BranchGuangdong 516000China

Multiple borehole samples are collected from the Baiyun Depression in deep-water area of the northern South China Sea(SCS)in an effort to reconstruct transgression processes during the Paleogene based on palynalgal *** study indicates that the Baiyun Depression generated a large group of palynopore assemblages and fluvial/lacustrine-related algae during the early and middle Eocene when the Wenchang Formation was *** entire depression was dominated by fluvial and lacustrine facies before *** eastern and southeastern sags transitioned to shallow marine environment by generating a large abundance of marine dinoflagellates during the Enping deposition of the late ***,the southern uplift zone simply yielded fluvial/lacustrine-related palynopores and algae,and was dominated by the fluvial and lacustrine environment during the early stage of the Enping Formation,prior to shifting into transitional setting in the later *** sags remained extensive fluvial and delta facies without existence of marine *** was until the depositional stage of the Zhuhai Formation(Oligocene)that the overall depression was strongly impacted from transgression *** eastern and southeastern sags were mainly under deep marine setting on a continental slope while northwestern and southern areas developed transitional *** distribution and accumulation patterns varied greatly among sub-sags,the overall Baiyun Depression was characterized by widespread development of marine *** should be noted that the northwestern sag also partly generated large-scale river delta *** to the eustatic rise and change of SCS spreading axis,the overall Baiyun Depression was mostly influenced by the deep marine environment on a continental slope during the early *** northwestern sag and southern uplift zone were found plentiful marine *** summary,transgression initiated from the ea

关键词： South China Sea Paleogene transgression sedimentary environment plant ecology

In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

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Chinese Medical Journal 2024年第8期137卷 990-996页

作者： yu Han zehua Shao Zirui Sun Yan Han Hongdang Xu Shubo Song Xiangbin Pan Peter P.T.de Jaegere Taibing Fan Gejun Zhang Department of Structure Heart Disease Central China Fuwai Hospital of Zhengzhou UniversityZhengzhouHenan 451460China Children’s Heart Center Central China Fuwai Hospital of Zhengzhou UniversityZhengzhouHenan 451460China Department of Anesthesiology Central China Fuwai Hospital of Zhengzhou UniversityZhengzhouHenan 451460China Department of Structure Heart Disease Fuwai Hospital Chinese Academy of Medical SciencesBeijing 100037China Department of Cardiology Erasmus MCRotterdam 3015 GDNetherlands

Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional(3D)-printed models for planning PPVI with the Venus ***:Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou ***:3D model bench testing altered treatment strategy in all patients(100%).One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor *** the remaining 14 patients,valve size and/or implantation location was altered to avoid valve migration and/or compression coronary *** four patients,it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract(RVOT)(n=2)or risk of compression coronary artery(n=2).Concerning sizing,we found that an oversize of 2-5 mm *** of the valve was dictated by the flaring of the in-and outflow portion in the pulmonary *** was successful in all 14 patients(absence of valve migration,no coronary compression,and none-to-mild residual pulmonary regurgitation[PR]).The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group(36[2]vs.32[4],Z=-3.77,P<0.001).Conclusions:In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique,as 2-5 mm sufficed.

关键词： Heart valve prosthesis implantation Percutaneous pulmonary valve intervention Pulmonary regurgitation bench testing 3D printing Venus P-valve

Characteristics and Influencing Factors of Microplastics in Snow in the Inner Mongolia Plateau, China

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Engineering 2024年第6期37卷 69-77页

作者： Hongwei yu Junrong Shao Huawei Jia Diga Gang Baiwen ma Chengzhi Hu State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Changjiang Survey PlanningDesign and Research Co.Ltd.Wuhan 430010China

Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution *** can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially thre... 详细信息

Microplastics(MPs;mate *** collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and *** results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow *** were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great ***-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional *** may have an interference effect on the individual growth and functional expression of microorganisms in *** addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of *** instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban *** MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.

关键词： Human activities Snow Microplastics Microbial community Urban function Environmental effect

A porous Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3) light color adjustable phosphor:Luminescent property and application of warm white LED

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Journal of Rare Earths 2024年第8期42卷 1421-1428,I0001页

作者： yunxiao ma Chao Linghu Ming Yang Hui yu Xiangting Dong Long Xia School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun130022China School of materials Science and Engineering Harbin Institute of Technology(Weihai)Weihai264209China

Light emitting diode(LED) is the fourth generation lighting source,but it has some shortcomings such as complex chip packaging process and the unbalanced light color of phosphor in long-time *** this study,a kind of Eu-terephthalic acid/Tb-sulfosalicylate/ZrO_(2)/ZnZrO_(3)(Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3))phosphor with warm white light emission properties was prepared,and the warm white light LED(wWLEDs) was successfully prepared by encapsulating Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3) phosphors together with 270 nm *** ZrO_(2)/ZnZrO_(3),Tb-SSA/ZrO_(2)/ZnZrO_(3) and Eu-PTA/ZrO_(2)/ZnZrO_(3) samples show blue emission,green emission and red emission under deep ultraviolet(UV,270 nm) excitation,*** Tb-SSA and Eu-PTA are co-doped into ZrO_(2)/ZnZrO_(3) matrix with blue emission to achieve the warm white light emission,and the light color can be adjusted by controlling the doping amount of Eu^(3+)-and Tb^(3+).Through the excitation method of single-component phosphor by the single chip,the complex chip packaging process of w-LED can be *** doping rare earth organic complexes into porous ZrO_(2)/ZnZrO_(3) matrix,the problems of the light color unbalanced of phosphor and the low luminescence intensity of rare earth doped metal oxides composites can be solved.

关键词： Eu-PTA/Tb-SSA/ZrO_(2)/ZnZrO_(3) Luminescence material Light color adjustable phosphor Warm white emission W-WLEDs Rare earths

Stage separation of recoverable liquid launch vehicle by using moving pulsating ball analogue for propellant sloshing

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Chinese Journal of Aeronautics 2024年第2期37卷 360-370页

作者： yu LU Baozeng yuE Bailong HAO Bole ma Feng LIU yuanyuan CHANG School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

In the process of stage separation of recoverable liquid launch vehicles,because of the large amount of residual fuel in the storage tanks,the influence of liquid sloshing on separation safety must be *** calculation simplicity and operation practicability,the Moving Pulsating Ball Model(MPBM)of large amplitude liquid sloshing is introduced into the calculation of launch vehicle stage *** the dynamic equation of the model with the energy relationship during"breathing movement",the formula calculating the force of liquid on the rigid body is *** with the calculations of commercial CFD calculation software,the accuracy of MPBM model is ***,all the external forces and moments are applied to the rigid body of the stages,so that the translational and rotational dynamic equations of the stages are obtained *** to the relative position of the two stages,the geometric shape of the interstage section and the engine of the second stage,the minimum clearance in the separation process can be decided to guarantee that the separation process is safe.

关键词： Moving Pulsating Ball Model(MPBM) Dynamics of stage separation Large amplitude sloshing Recoverable liquid launch vehicle Flight dynamics

Unravelling the nature of the active species as well as the Mn doping effect over gamma-Al_(2)O_(3) catalyst for eliminating AsH_(3) and PH_(3)

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Journal of Environmental Sciences 2024年第2期136卷 213-225页

作者： Bowen Xu Jiaxin Qu Xueqian Wang Langlang Wang yu Pu Ping Ning Yibing Xie Yixing ma Qiang ma Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China School of Architecture and Civil Engineering Chengdu UniversityChengdu 610106China

To investigate the enhancing effect of Mn on the performance of simultaneous catalytic oxidation of AsH_(3)and PH_(3)by CuO-Al_(2)O_(3)in a reducing atmosphere under micro-oxygen conditions,Cu-Mn modifiedγ-Al_(2)O_(3)catalysts were *** characteristics of the catalysts showed that Mn reduced the crystallinity of the active CuO component,increased the number of oxygen vacancies and acidic sites on the catalyst surface,enhanced the mobility of surface oxygen,and the interaction between copper and manganese promoted the redox cycling ability of the catalysts and improved their oxidation performance,which increased the conversion frequency(TOF)by 2.54×10^(-2)to 3.07×10^(-2)sec^(-1).On the other hand,the introduction of Mn reduced the production of phosphate and As_(2)O_(3)on the catalyst surface by30.96%and 44.9%,which reduced the coverage and inerting of the active sites by phosphate and As_(2)O_(3),resulting in an 8 hr(6 hr)improvement in the stability of PH_(3)(AsH_(3))removal.

关键词： AsH_(3)-PH_(3)removal Oxygen activation Mn doping Stability enhancement

Evaluation on Configuration Stiffness of Overconstrained 2R1T Parallel Mechanisms

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 62-82页

作者： Xuejian ma Zhenghe Xu yundou Xu yu Wang Jiantao Yao Yongsheng Zhao Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging and Stamping Technology and Science of Ministry of National Education Yanshan UniversityQinhuangdao 066004China

Currently,two rotations and one translation(2R1T)three-degree-of-freedom(DOF)parallel mechanisms(PMs)are widely applied in five-DOF hybrid machining ***,there is a lack of an effective method to evaluate the configuration stiffness of mechanisms during the mechanism design *** is a challenge to select appropriate 2R1T PMs with excellent stiffness performance during the design *** the operational status of 2R1T PMs,the bending and torsional stiffness are considered as indices to evaluate PMs'configuration ***,a specific method is proposed to calculate these stiffness ***,the various types of structural and driving stiffness for each branch are assessed and their specific values ***,a rigid-flexible coupled force model for the over-constrained 2R1T PM is established,and the proposed evaluation method is used to analyze the configuration stiffness of the five 2R1T PMs in the entire ***,the driving force and constraint force of each branch in the whole working space are calculated to further elucidate the stiffness evaluating results by using the proposed method *** obtained results demonstrate that the bending and torsional stiffness of the 2RPU/UPR/RPR mechanism along the x and y-directions are larger than the other four mechanisms.

关键词： Parallel mechanism Stiffness Over-constrained Three degrees of freedom

Risk assessment of oil and gas investment environment in countries along the Belt and Road Initiative

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Petroleum Science 2024年第2期21卷 1429-1443页

作者： Bao-Jun Tang Chang-Jing Ji yu-Xian Zheng Kang-Ning Liu Yi-Fei ma Jun-yu Chen Center for Energy and Environmental Policy Research Beijing Institute of TechnologyBeijing100081China School of management and Economics Beijing Institute of TechnologyBeijing100081China Collaborative Innovation Center of Electric Vehicles in Beijing BeijingChina Sustainable Development Research Institute for Economy and Society of Beijing BeijingChina Institute of Carbon Neutrality ShanghaiTech UniversityShanghai201210China

With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.

关键词： Belt and Road Initiative Oil and Gas Investment Risk assessment