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The Mathematical and Physical Theory of Rational Human Intelligence: Complete Empirical-Digital Properties;Full Electrochemical-Mechanical Model (Part I: Mathematical Foundations)
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作者 Leo Depuydt 《Advances in Pure Mathematics》 2013年第5期491-561,共71页
The design of this paper is to present the first installment of a complete and final theory of rational human intelligence. The theory is mathematical in the strictest possible sense. The mathematics involved is stric... The design of this paper is to present the first installment of a complete and final theory of rational human intelligence. The theory is mathematical in the strictest possible sense. The mathematics involved is strictly digital—not quantitative in the manner that what is usually thought of as mathematics is quantitative. It is anticipated at this time that the exclusively digital nature of rational human intelligence exhibits four flavors of digitality, apparently no more, and that each flavor will require a lengthy study in its own right. (For more information,please refer to the PDF.) 展开更多
关键词 Artificial INTELLIGENCE Boolean ALGEBRA Booles ALGEBRA Black Box Theories Brain Science Cognition Cognitive Science Digital MATHEMATICS Electricity and Magnetism J.-L. Lagrange and Partial Differential Equations J. C. Maxwell’s Theory of Electromagnetism Neuroscience Non-Quantitative and Quantitative MATHEMATICS Physics RATIONAL Human INTELLIGENCE COMPLETE Theory of RATIONAL Thought and Language
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Elementary Fermions: Strings, Planck Constant, Preons and Hypergluons
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作者 Doron Kwiat 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期82-100,共19页
Using real fields instead of complex ones, it is suggested here that the fermions are pairs of coupled strings with an internal tension. The interaction between the two coupled strings is due to an exchange mechanism ... Using real fields instead of complex ones, it is suggested here that the fermions are pairs of coupled strings with an internal tension. The interaction between the two coupled strings is due to an exchange mechanism which is proportional to Planck’s constant. This may be the result of two massless bosons (hypergluons) coupled by a preon (prequark) exchange. It also gives a physical explanation to the origin of the Planck constant, and origin of spin. 展开更多
关键词 FERMIONS Preons Hypergluons strings Real Fields Planck Constant INTERFERENCE SPIN
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Passability test and simulation of sand control string with natural gas hydrates completion in large curvature hole
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作者 Hao-xian Shi Yan-jiang Yu +12 位作者 Ru-lei Qin Jun-yu Deng Yi-xin Zhong Li-qiang Qi Bin Li Bo Fan Qiu-ping Lu Jian Wang Kui-wei Li Ye-cheng Gan Gen-long Chen Hao-wen Chen Zhi-ming Wu 《China Geology》 CAS CSCD 2023年第1期27-36,共10页
To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells... To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells were selected to carry out the running test of sand control string with pre-packed screen.Meanwhile,the running simulation was performed by using the Landmark software.The results show that the sand control packer and screen can be run smoothly in the wellbore with a dogleg angle of more than 20°/30 m and keep the structure stable.Additionally,the comprehensive friction coefficient is 0.4,under which and the simulation shows that the sand control string for hydrate exploitation can be run smoothly.These findings have important guiding significance for running the completion sand control string in natural gas hydrate exploitation. 展开更多
关键词 Natural gas hydrates(NGHs) completion sand control string Large curvature borehole Passability test Friction coefficient Oil and gas exploration engineering NGHs exploration trial engineering
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A Combined Heterotic String and Kähler Manifold Elucidation of Ordinary Energy,Dark Matter,Olbers’s Paradox and Pure Dark Energy Density of the Cosmos
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作者 Mohamed S.El Naschie 《Journal of Modern Physics》 2017年第7期1101-1118,共18页
We utilize the topological-geometrical structure imposed by the Heterotic superstring theory on spacetime in conjunction with the K3 K&auml;hler manifold to explain the mysterious nature of dark matter and its cou... We utilize the topological-geometrical structure imposed by the Heterotic superstring theory on spacetime in conjunction with the K3 K&auml;hler manifold to explain the mysterious nature of dark matter and its coupling to the pure dark energy density of the cosmos. The analogous situations in the case of a Kerr black hole as well as the redundant components of the Riemannian tensor are pointed out and the final result was found to be in complete agreement with all previous theoretical ones as well as all recent accurate measurements and cosmic observations. We conclude by commenting briefly on the Cantorian model of Zitterbewegung and the connection between Olbers’s paradox and dark energy. 展开更多
关键词 Heterotic strings K3 Kahler Manifold Dark Matter Pure Heterotic Dark Energy Einsteins Relativity Accelerated Cosmic Expansion Negative Gravity Fractal Spacetime E-Infinity Theory Kerr Black Holes Geometry Kaluza-Klein Theory Dvoretzkys Theorem Empty Set Zero Set Connes Noncommutative Geometry tHooft Renormalon STATE Vector Reduction Density Matrix tHooft Fractal Spacetime Transfinite Cellular Automata Interpretation of Quantum Mechanics ZITTERBEWEGUNG Olberss Dark Sky Paradox
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Discharge Characteristics of a Triple-Well Diode-String ESD Clamp
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作者 Jin Young Choi 《Circuits and Systems》 2018年第5期75-86,共12页
In this work, DC and transient characteristics of a 4 diode string utilizing triple-well technologies as a VDD-VSS clamp device for ESD protection are analyzed in detail based on 2-dimensional device and mixed-mode si... In this work, DC and transient characteristics of a 4 diode string utilizing triple-well technologies as a VDD-VSS clamp device for ESD protection are analyzed in detail based on 2-dimensional device and mixed-mode simulations. It is shown that there exists parasitic pnp bipolar transistor action in this device leading to a sudden increase in DC substrate leakage if anode bias is getting high. Through transient simulations for a 2000 V PS-mode HBM ESD discharge event, it is shown that the dominant discharge path is the one formed by a parasitic pnpn thyristor and a parasitic npn bipolar transistor in series. Percentage ratios of the various current components regarding the anode current at its current peaking are provided. The mechanisms involved in ESD discharge inside the diode-string clamp utilizing triple-well technologies are explained in detail, which has never been done anywhere in the literature based on simulations or measurements. 展开更多
关键词 ESD Protection DIODE string TRIPLE well Device Simulation CMOS RF IC
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Mechanism and prevention method of drill string uplift during shut-in after overflow in an ultra-deep well
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作者 YIN Hu SI Menghan +2 位作者 LI Qian JANG Hongwei DAI Liming 《Petroleum Exploration and Development》 2018年第6期1139-1145,共7页
Drill string will sustain large uplift force during the shut-in period after gas overflow in an ultra-deep well, and in serious case, it will run out of the wellhead. A calculation model of uplift force was establishe... Drill string will sustain large uplift force during the shut-in period after gas overflow in an ultra-deep well, and in serious case, it will run out of the wellhead. A calculation model of uplift force was established to analyze dynamic change characteristics of the uplift force of drill string during the shut-in period, and then a management procedure for the uplift risk during the shut-in period after gas overflow in the ultra-deep well was formed. Cross section method and pressure area method were used to analyze the force on drill string after shut-in of well, it was found that the source of uplift force was the "fictitious force" caused by the hydrostatic pressure in the well. When the fictitious force is in the opposite direction to the gravity, it is the uplift force. By adopting the theory of annular multiphase flow, considering the effects of wellbore afterflow and gas slippage, the dynamic change of the pressure and fluid in the wellbore and the uplift force of drill string during the shut-in period were analyzed. The magnitude and direction of uplift force are related to the length of drill string in the wellbore and shut-in time, and there is the risk of uplift of drill string when the length of drill string in the wellbore is smaller than the critical drill string length or the shut in time exceeds the critical shut in time. A set of treatment method and process to prevent the uplift of drill string is advanced during the shut-in period after overflow in the ultra-deep well, which makes the risk management of the drill string uplift in the ultra-deep well more rigorous and scientific. 展开更多
关键词 ultra-deep well drilling OVERFLOW shut-in DRILL string UPLIFT force axial load
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String Gauge Symmetries in the Conformally Gauge-Fixed Polyakov D1 Brane Action in the Presence of Background Gauge Fields 被引量:1
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作者 Usha Kulshreshtha Daya Shankar Kulshreshtha 《Journal of Modern Physics》 2012年第1期110-115,共6页
Recently we have studied the instant-form quantization (IFQ) and the light-front quantization (LFQ) of the conformally gauge-fixed Polyakov D1 brane action using the Hamiltonian and path integral formulations. The IFQ... Recently we have studied the instant-form quantization (IFQ) and the light-front quantization (LFQ) of the conformally gauge-fixed Polyakov D1 brane action using the Hamiltonian and path integral formulations. The IFQ is studied in the equal world-sheet time framework on the hyperplanes defined by the world- sheet time σ0 = τ = constant and the LFQ in the equal light-cone world-sheet time framework, on the hyperplanes of the light-front defined by the light-cone world-sheet time . The light-front theory is seen to be a constrained system in the sense of Dirac in contrast to the instant-form theory. However, owing to the gauge anomalous nature of these theories, both of these theories are seen to lack the usual string gauge symmetries defined by the world-sheet reparametrization invariance (WSRI) and the Weyl invariance (WI). In the present work we show that these theories when considered in the presence of background gauge fields such as the NSNS 2-form gauge field or in the presence of gauge field and the constant scalar axion field , then they are seen to possess the usual string gauge symmetries (WSRI and WI). In fact, these background gauge fields are seen to behave as the Wess-Zumino/Stueckelberg fields and the terms containing these fields are seen to behave as Wess-Zumino or Stueckelberg terms for these theories. 展开更多
关键词 LIGHT-FRONT QUANTIZATION Hamiltonian QUANTIZATION Path Integral QUANTIZATION Constrained Dynamics Constraint QUANTIZATION GAUGE SYMMETRY string GAUGE SYMMETRY string Theory D-BRANE Actions Polyakov Action Light-Cone QUANTIZATION
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String Theory with Oscillating Space-Time Dimension Number
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作者 Ding-Yu Chung 《Journal of Modern Physics》 2014年第6期464-472,共9页
In conventional string theory with fixed space-time dimension number, the extra space dimensions are compactized. In string theory with oscillating space-time dimension number, dimension number oscillates between 11D ... In conventional string theory with fixed space-time dimension number, the extra space dimensions are compactized. In string theory with oscillating space-time dimension number, dimension number oscillates between 11D and 10D and between 10D and 4D reversibly, and there is no compactization. Dimension number decreases with decreasing speed of light and increasing rest mass. The 4D particle has the lowest speed of light and the highest rest mass. The two different oscillations between 10D and 4D are the stepwise oscillation passing through every dimension number and the direct oscillation oscillating directly between 10D and 4D without the intermediate dimension numbers. Dark energy represents the stepwise oscillation, and dark energy becomes observable only when it has 4D space-time. 4D baryonic matter and 4D dark matter represent the direct oscillation directly from 10D to 4D. Our universe is the dual cyclic universe of the dark energy universe and the baryonic-dark matter universe. The Big Bang in the baryonicdark matter universe produced irreversible kinetic energy that stopped the reversible direct oscillation. The reversible direct oscillation will resume after the Big Crush to remove irreversible kinetic energy. Our cyclic universe started from the zero-energy universe through the four-stage transformation. The theoretical calculated percentages of dark energy, dark matter, and baryonic matter are 68.3, 26.4, and 5.3, respectively, in agreement with observed 68.3, 26.8, and 4.9, respectively. According to the calculation, dark energy started in 4.28 billion years ago in agreement with the observed 4.71 ± 0.98 billion years ago. 展开更多
关键词 string Theory DIMENSION NUMBER Oscillation Cosmology Dual UNIVERSE Big Bang INFLATION Cyclic UNIVERSE DARK Energy DARK MATTER Baryonic MATTER Force Fields
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Towards 6D Little String Theory of Particles
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作者 Risto Raitio 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期546-561,共16页
A model for particles based on preons in chiral, vector and tensor/graviton supermultiplets of unbroken global supersymmetry is engineered. The framework of the model is little string theory. Phenomenological predicti... A model for particles based on preons in chiral, vector and tensor/graviton supermultiplets of unbroken global supersymmetry is engineered. The framework of the model is little string theory. Phenomenological predictions are discussed. 展开更多
关键词 Standard Model Composite Models SUPERSYMMETRY Little string Theory T-DUALITY HOLOGRAPHY
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用于截瘫FES行走的三维上肢力动态测量系统
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作者 明东 万柏坤 +1 位作者 胡勇 梁智仁 《实验力学》 CSCD 北大核心 2005年第1期90-96,共7页
功能性电刺激(FES)技术已被广泛用于截瘫病人行走能力的恢复,但作为评估截瘫FES行走效率的重要指标,三维上肢力状况的研究至今仍十分有限,亟待深入开展。本文研制出了一套可用于截瘫FES行走的三维上肢力动态测量系统,该系统在一个标准... 功能性电刺激(FES)技术已被广泛用于截瘫病人行走能力的恢复,但作为评估截瘫FES行走效率的重要指标,三维上肢力状况的研究至今仍十分有限,亟待深入开展。本文研制出了一套可用于截瘫FES行走的三维上肢力动态测量系统,该系统在一个标准步行器框架上装备有 12个应力应变片电桥,通过专用的隔离放大及A/D转换装置与计算机相连,经过标定后,截瘫FES行走时的上肢支撑力数据就可以被系统实时获得并显示。测力系统在应变片位置的确定以及“冗余-优化”方法的采用等多个方面保证了测量的可靠性和准确性,后续的校准实验显示系统的非线性、交互干扰和力学精度误差分别小于 2. 901%, 3. 188%和 1. 01%。研究中,一例截瘫患者作为志愿者按照正常的FES行走训练程序进行了相关测试,以验证新系统在行走能力评估方面的临床前景,结果表明其可用于: 1)截瘫FES行走效率的评估; 2)病人自我训练的控制指导; 3)作为反馈信号选择一种有效的FES模式和阵列。 展开更多
关键词 FES A/D 线 S
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New Evidence, Conditions, Instruments &Experiments for Gravitational Theories
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作者 Benjamin T. Solomon 《Journal of Modern Physics》 2013年第8期183-196,共14页
Two significant findings compel a rethink of physical theories. First, using a 7-billion-year-old gamma-ray burst, Nemiroff (2012) showed that quantum foam could not exists. And second, Solomon (2011) showed that grav... Two significant findings compel a rethink of physical theories. First, using a 7-billion-year-old gamma-ray burst, Nemiroff (2012) showed that quantum foam could not exists. And second, Solomon (2011) showed that gravitational acceleration is not associated with the gravitating mass, that gravitational acceleration g is determined solely by τ the change in time dilation over a specific height multiplied by c2 or g = τc2. Seeking consistency with Special Theory of Relativity, as means to initiate this rethink, this paper examines 12 inconsistencies in physical theories that manifest from empirical data. The purpose of this examination is to identify how gravitational theories need to change or be explored, to eliminate these 12 inconsistencies. It is then proposed that spacetime is much more sophisticated than just a 4-dimensional continuum. And, that the Universe consists of at least two layers or “kenos” (Greek for vacuous), the 4-dimensional kenos, spacetime (x, y, z, t) and the 3-dimensional kenos, subspace (x, y, z) that are joined at the space coordinates (x, y, z). This explains why electromagnetic waves are transverse, and how probabilities are implemented in Nature. This paper concludes by proposing two new instruments and one test, to facilitate research into gravitational fields, the new torsion-, tension- and stress-free near field gravity probe, the gravity wave telescope, and a non-locality test. 展开更多
关键词 RELATIVITY Special THEORY of RELATIVITY General THEORY of RELATIVITY Entanglement Baking Bread Transverse WAVE Electromagnetism Separation Vectors Gamma Ray Burst QUARKS GRAVITY Modification Exotic Matter Photons strings Shielding Cloaking INVISIBILITY Near Field GRAVITY Probe WAVE Function Gaussian
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Workover String Mechanical Model and Calculation of Slanted and Horizontal Well
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作者 Bingguo Du Hanqiao Jiang 《Journal of Applied Mathematics and Physics》 2015年第5期537-544,共8页
Force analysis and calculation of workover string in the slanted and horizontal well are the basis of designing and checking string strength, selecting tools and determining operation parameters, which determine the o... Force analysis and calculation of workover string in the slanted and horizontal well are the basis of designing and checking string strength, selecting tools and determining operation parameters, which determine the operation safety and success of engineering accidence treatment. In this paper, by comprehensive consideration of wellbore structure, string assembly, string load and workover operation conditions, the workover string mechanical model has been built under three kinds of working states of lifting, lowering and rotating. The downhole string mechanics has been analyzed and calculated. By field verification, the string assembly, tool selection and operation parameter optimization can be achieved, which can improve the safety and success rates of workover engineering accident treatment. 展开更多
关键词 Slanted well Horizontal well WORKOVER string MECHANICS Model TORQUE ACCIDENT Treatment
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水平井射孔完井表皮系数分解计算方法 被引量:14
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作者 曾文广 米强波 《钻井液与完井液》 CAS 北大核心 2005年第B05期105-106,129,共3页
近井地带的表皮系数是评价油气井产能和完井效率的重要参数。由不稳定试井法确定的表皮系数,是一个既包括钻井液、完井液对近井地带储层污染与堵塞的影响,又包括钻井、完井的不完善和增产措施影响的总表皮系数,不能评价某一施工环节的... 近井地带的表皮系数是评价油气井产能和完井效率的重要参数。由不稳定试井法确定的表皮系数,是一个既包括钻井液、完井液对近井地带储层污染与堵塞的影响,又包括钻井、完井的不完善和增产措施影响的总表皮系数,不能评价某一施工环节的好坏。针对完井施工过程中如何计算各表皮系数以引导完井现场施工的问题,提出了一种新的分解计算水平井表皮系数的方法,即:将水平井总表皮系数分解为打开程度表皮系数Spt、射孔总表皮系数Spf、钻井污染表皮系数Sd方法,并反推出各分项表皮系数的计算方法。它无需压力恢复曲线或压降曲线,仅利用DST数据即可计算。通过DST测试资料预测油井各施工环节的污染情况,以便选择最佳的钻井、完井方法以及优化完井参数并用于指导初期增产施工。 展开更多
关键词 线 线 DST Ssc Spf
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Completion and stimulation trends in North American unconventional plays and resulting impact on well productivity 被引量:3
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作者 Roman Galchenko Qing Liu +5 位作者 Yan Gao Yu Liu David He Josh Zhang Huailiang Liu Xiaohua Ke 《钻探工程》 2021年第10期1-12,共12页
过去十年,非常规油气勘探开发在全球范围内大幅扩张。水平钻井和多级水力压裂技术也在不断地发展和创新,使得超长水平井成为可能。同时,因为压裂强度不断增加,作业者可以最大限度地提高储层接触面积和对储层的改造体积(SRV)。然而,完井... 过去十年,非常规油气勘探开发在全球范围内大幅扩张。水平钻井和多级水力压裂技术也在不断地发展和创新,使得超长水平井成为可能。同时,因为压裂强度不断增加,作业者可以最大限度地提高储层接触面积和对储层的改造体积(SRV)。然而,完井优化方面的挑战仍然存在,作业者持续不断地尝试和试验各种完井与增产参数组合,以确保非常规油气藏开发的经济可行性。优选最佳的完井与增产参数组合是一项非常关键的任务,应结合油气田的具体储层特征进行优化。本文总结了2014—2020年间北美9个主要非常规油气藏的压裂增产趋势,包括Marcellus,Haynesville,Barnett,Utica,Bone Spring,Bakken,Wolfcamp Midland,Eagle Ford,Scoop/Stack。分析了各油气田几个关键的完井和增产参数的整体趋势,同时还评估了单个参数(如水平段压裂长度、支撑剂强度、段间距等)对井产能的影响。然后对比分析相应的初始井产量(90天平均初始产量),评估各个参数对产能的影响,从而确定每个完井参数的最佳范围,以实现产能最优化。 展开更多
关键词
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Key technologies and practice for gas field storage facility construction of complex geological conditions in China 被引量:3
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作者 MA Xinhua ZHENG Dewen +3 位作者 SHEN Ruichen WANG Chunyan LUO Jinheng SUN Junchang 《Petroleum Exploration and Development》 2018年第3期507-520,共14页
In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storag... In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storage construction technologies were established, mainly including UGS site selection and evaluation, key index design, well drilling and completion, surface engineering and operational risk warning and assessment, etc. The effect of field application was discussed and summarized. Firstly, trap dynamic sealing capacity evaluation technology for conversion of UGS from the fault depleted or partially depleted gas reservoirs. A key index design method mainly based on the effective gas storage capacity design for water flooded heterogeneous gas reservoirs was proposed. To effectively guide the engineering construction of UGS, the safe well drilling, high quality cementing and high pressure and large flow surface injection and production engineering optimization suitable for long-term alternate loading condition and ultra-deep and ultra-low temperature formation were developed. The core surface equipment like high pressure gas injection compressor can be manufactured by our own. Last, the full-system operational risk warning and assessment technology for UGS was set up. The above 5 key technologies have been utilized in site selection, development scheme design, engineering construction and annual operations of 6 UGS groups, e.g. the Hutubi UGS in Xinjiang. To date, designed main indexes are highly consistent with actural performance, the 6 UGS groups have the load capacity of over 7.5 billion cubic meters of working gas volume and all the storage facilities have been running efficiently and safely. 展开更多
关键词 gas field STORAGE TRAP dynamic sealing capacity key index design effective STORAGE volume drilling and completion in ultra-deep and ultra-low pressure formation ALTERNATING load surface engineering core equipment risk assessment and control
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二连油田巴38断块保护油层钻井液技术 被引量:1
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作者 贾东民 左凤江 +3 位作者 李长荣 丁光波 闫睿昶 郭志强 《钻井液与完井液》 CAS 北大核心 2005年第B05期48-49,52,122,共4页
巴38断块储层物性从中孔特低渗到中孔中渗,非均质性强,属于强水敏、强盐敏地层。针对巴38断块储层特征和现场使用的钾铵基聚合物钻井液体系特点,研究出了适用于巴38断块的油层保护剂L-RP-2。该油层保护剂L-RP-2中引入了中-低分子量聚合... 巴38断块储层物性从中孔特低渗到中孔中渗,非均质性强,属于强水敏、强盐敏地层。针对巴38断块储层特征和现场使用的钾铵基聚合物钻井液体系特点,研究出了适用于巴38断块的油层保护剂L-RP-2。该油层保护剂L-RP-2中引入了中-低分子量聚合物,利用聚合物分子链可以将不同形状和不同粒度的惰性颗粒,包括原井浆中的固相颗粒链接起来共同对储层进行有效封堵。室内评价结果表明,油层保护剂L-RP-2对岩心的封堵效率大于85%,封堵深度小于10mm,满足了油层封堵技术的要求。加有油层保护剂L-RP-2的保护油层钻井液体系现场应用40口井,在进行测试的15口井中,12口井共计13层表皮系数均小于零,为完善井,3口井表皮系数小于1,为轻微损害井,可见油层保护剂L-RP-2的应用取得了良好的深护油层效果。 展开更多
关键词 使
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Attenuation of microwave transmission in a diameter-variable drill string bore
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作者 XIA Wenhe MENG Yingfeng +1 位作者 TANG Bo GUAN Wenting 《Petroleum Exploration and Development》 2018年第3期521-528,共8页
With the drill string hole being regarded as an ultra-long irregular lossy cylindrical waveguide, the optimal frequency point for microwave transmission was calculated according to the electromagnetic wave coupling th... With the drill string hole being regarded as an ultra-long irregular lossy cylindrical waveguide, the optimal frequency point for microwave transmission was calculated according to the electromagnetic wave coupling theory, the attenuation law and efficient transmission distance of microwave channel were obtained and the microwave mode in the waveguide was analyzed. Furthermore, the channel model and signal attenuation model were established by the microwave transmission equivalent circuit method. The power attenuation coefficient per unit of length was proposed to simplify the analysis on effective transmission distance for the ultra-long drill string. The optimal frequency points of 139.7 mm(5.5 in) and 127 mm(5 in) API drill pipes are 2.04 GHz and 2.61 GHz, respectively, and there are several inner diameter varying sections and break points in the drill string hole along the axial direction. The microwave transmission suffers a lot of reflections. The channel impedance change is a key factor affecting the transmission quality. The lab and field tests reveal that the attenuation model established in this paper is accurate, and it is applicable to the design of microwave transmission measurement while drilling system. 展开更多
关键词 gas DRILLING measure WHILE DRILLING microwave TRANSMISSION DRILL string BORE optimal frequency point cylindrical waveguide effective TRANSMISSION distance
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Mechanical Analysis of a Multi-Test String in High-Temperature and High-Pressure Deep Wells
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作者 Zubing Tang 《Fluid Dynamics & Materials Processing》 EI 2023年第8期2161-2170,共10页
The mechanical behavior of the test string in deep wells is generally relatively complex as a result of the high temperature and high pressure,severe dogleg and buckling effects,which in some circumstances can even le... The mechanical behavior of the test string in deep wells is generally relatively complex as a result of the high temperature and high pressure,severe dogleg and buckling effects,which in some circumstances can even lead to string failure.Traditional computational methods for the analysis of these behaviors are often inaccurate.For this reason,here a more accurate mechanical model of the test string is introduced by considering variables such as temperature,pressure,wellbore trajectory,and buckling,as well as combining them with the deformation and string constraint conditions brought in by changes in temperature and pressure during the tripping,setting,and test operations.The model is validated by applying it to a specific high-pressure gas well(located in Northeast Sichuan). 展开更多
关键词 Test string high temperature and high pressure BUCKLING subdividing operation process mechanical model
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Detachable string magnetically controlled capsule endoscopy for the noninvasive diagnosis of esophageal diseases:A prospective,blind clinical study
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作者 Yan-Ling Yang Huang-Wen Qin +5 位作者 Zhao-Yu Chen Hui-Ning Fan Yi Yu Wei Da Jin-Shui Zhu Jing Zhang 《World Journal of Gastroenterology》 SCIE CAS 2024年第9期1121-1131,共11页
BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being ... BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being applied for the detection of stomach and small intestinal diseases,but its application in treating esophageal diseases is not widespread.AIM To evaluate the safety and efficacy of detachable string MCE(ds-MCE)for the diagnosis of esophageal diseases.METHODS Fifty patients who had been diagnosed with esophageal diseases were pros-pectively recruited for this clinical study and underwent ds-MCE and conven-tional EGD.The primary endpoints included the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for patients with esophageal diseases.The secondary endpoints consisted of visualizing the esophageal and dentate lines,as well as the subjects'tolerance of the procedure.RESULTS Using EGD as the gold standard,the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for esophageal disease detection were 85.71%,86.21%,81.82%,89.29%,and 86%,respectively.ds-MCE was more comfortable and convenient than EGD was,with 80%of patients feeling that ds-MCE examination was very comfortable or comfortable and 50%of patients believing that detachable string v examination was very convenient.CONCLUSION This study revealed that ds-MCE has the same diagnostic effects as traditional EGD for esophageal diseases and is more comfortable and convenient than EGD,providing a novel noninvasive method for treating esophageal diseases. 展开更多
关键词 Clinical trial Detachable string magnetically controlled capsule endoscopy ESOPHAGOGASTRODUODENOSCOPY Noninvasive diagnosis Esophageal diseases
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裸眼完井出砂预测模型研究 被引量:11
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作者 王金龙 闫相祯 杨秀娟 《石油大学学报(自然科学版)》 EI CSCD 北大核心 2005年第2期93-96,100,共5页
油田开采到中后期,疏松砂岩油藏的出砂问题已成为影响油井产能和损害设备的严重问题。为了研究裸眼完井的出砂机理,根据岩石力学及弹塑性力学理论,对直井井壁围岩应力分布进行了分析计算,采用Mohr Coulom准则及复变函数方法建立了非均... 油田开采到中后期,疏松砂岩油藏的出砂问题已成为影响油井产能和损害设备的严重问题。为了研究裸眼完井的出砂机理,根据岩石力学及弹塑性力学理论,对直井井壁围岩应力分布进行了分析计算,采用Mohr Coulom准则及复变函数方法建立了非均匀地应力作用下油井出砂的解析模型。利用该模型和已知的出砂判别准则即可确定油井的出砂现状。在中原油田现场的应用实例表明,该模型预测结果与现场工程实践中已有的油井出砂经验预测模型相吻合。 展开更多
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