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Numerical simulation of non-Archie electrophysical property of saturated rock with lattice Boltzmann method

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petroleum Science 2009年第1期6卷 24-28页

作者： Yue Wenzheng Tao Guo Liu Dongming Yang Wendu State Key Laboratory of petroleum resource and Prospecting China University of Petroleum Beijing 102249 China Key Laboratory of Earth Prospecting and information technology China University of Petroleum Beijing 102249 China Research Centre of Well Logging CNPC Key Laboratory of Well Logging China University of Petroleum Beijing 102249 China CNPC Logging Changqing Business Division Xi＇an Shaanxi 710201 China Sichuan petroleum Administration Logging Company Ltd. CNPC Chongqing 401147 China

The electrophysical property of saturated rocks is very important for reservoir identification and evaluation. In this paper, the lattice Boltzmann method （LBM） was used to study the electrophysical property of rock saturated with fluid because of its advantages over conventional numerical approaches in handling complex pore geometry and boundary conditions. The digital core model was constructed through the accumulation of matrix grains based on their radius distribution obtained by the measurements of core samples. The flow of electrical current through the core model saturated with oil and water was simulated on the mesoscopic scale to reveal the non-Archie relationship between resistivity index and water saturation （I-Sw）. The results from LBM simulation and laboratory measurements demonstrated that the I-Sw relation in the range of low water saturation was generally not a straight line in the log-log coordinates as described by the Archie equation. We thus developed a new equation based on numerical simulation and physical experiments. This new equation was used to fit the data from laboratory core measurements and previously published data. Determination of fluid saturation and reservoir evaluation could be significantly improved by using the new equation.

关键词： Non-Archie relation digital core model lattice Boltzmann method numerical simulation rock physical experiment

An efficient quantum secret sharing protocol with orthogonal product states

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Science china(Physics,Mechanics & Astronomy) 2007年第3期50卷 331-338页

作者： YANG YuGuang1,2, WEN QiaoYan3 & ZHU FuChen4 1 School of Computer, beijing university of technology, beijing 100022, china 2 State Key Laboratory of information Security, Graduate university of Chinese Academy of Sciences, beijing 100022, china 3 School of Science, beijing university of Posts and Telecommunications, beijing 100876, china 4 National Key Laboratory for Modern Communications, Chengdu 610041, china 1. School of Computer Beijing University of Technology Beijing 100022 China 2. State Key Laboratory of information Security Graduate University of Chinese Academy of Sciences Beijing 100022 China 3. School of Science Beijing University of Posts and Telecommunications Beijing 100876 China 4. National Key Laboratory for Modern Communications Chengdu 610041 China

An efficient quantum secret sharing protocol with orthogonal product states in the 33 Hilbert space is presented. The particles in the orthogonal product states form two particle sequences. One sequence is sent to Bob and the other is sent to Charlie after rearranging the particle orders. With the help of Alice, Bob and Charlie make the corresponding local measurement to obtain the information of the or- thogonal product states prepared. This protocol has many distinct features such as great capacity and high efficiency.

关键词： quantum secret sharing orthogonal product state orthogonal measurement

Fuzzy tolerance quotient spaces and fuzzy subsets

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Science china(information Sciences) 2010年第4期53卷 704-714页

作者： ZHANG Ling1 & ZHANG Bo2,3,4* 1Computer Science & technology College, Anhui university, Anhui 230039, china 2State Key Laboratory of Intelligent technology and Systems, beijing 100084, china 3Tsinghua National Laboratory of information Science & technology, beijing 100084, china 4information Science & technology College, Computer Science & technology Department, Tsinghua university, beijing 100084, china 1. Computer Science & technology College Anhui University Anhui 230039 China2. State Key Laboratory of Intelligent Technology and Systems Beijing 100084 China3. Tsinghua National Laboratory of Information Science & Technology Beijing 100084 China4. Information Science & Technology College Computer Science & Technology Department Tsinghua University Beijing 100084 China

The structure and characteristic of fuzzy subsets are discussed by using the concepts of granulation and hierarchy in quotient space theory. First, the equivalence relation based quotient space theory is extended to the fuzzy tolerance relation. Second, the isomorphism and its discriminant of fuzzy tolerance relations are discussed. Finally, by using the fuzzy tolerance relation to define the fuzzy subset, its properties are addressed. The main results are given below: (1) several equivalent statements of fuzzy tolerance relations; (2) the definition of isomorphism of fuzzy tolerance relations; (3) the isomorphic discriminant of fuzzy tolerance relations; (4) the definition and properties of fuzzy subsets based on the fuzzy tolerance relations; and (5) the necessary and sufficient condition of the isomorphism of fuzzy subsets. These results will help us further comprehend the concepts of fuzzy tolerance relations and fuzzy subsets.

关键词： Fuzzy tolerance relation quotient space isomorphism fuzzy subset

Episodic fluid movements in superimposed basin:Combined evidence from outcrop and fluid inclusions of the Majiang ancient oil reservoir,Guizhou Province

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Science china Earth Sciences 2008年第S2期51卷 78-87页

作者： XIANG CaiFu1,2,TANG LiangJie1,2,LI RuFeng1,2 & PANG XiongQi1,2 1 Basin and Reservoir Research Center,china university of petroleum,beijing 102.49,china 2 State Key Laboratory of petroleum resource and Prospecting,china university of petroleum,beijing 102.49,china 1. Basin and Reservoir Research Center China University of Petroleum Beijing 102249 China 2. State Key Laboratory of petroleum resource and Prospecting China University of Petroleum Beijing 102249 China

Combined evidence from the outcrop and the fluid inclusion assemblage (FIA) analysis indicates that there exist two episodes of fluid flow controlled by the tectonic activity. The first episode was recorded mainly in the reservoir rock of the Honghuayuan Formation,representing the fluid flow of hydrocarbon charging. The second episode occurred mainly along the fault systems,representing the fluid move-ment when the ancient oil reservoir was destroyed. The host mineral morphology,homogeneous tem-perature,and salinity of the FIAs record an episodic fluid movement. Characters of high homogenous temperature,low salinity and a quick temperature variation of the first episode fluid flow may indicate an early-stage fluid eruption,and correspondingly,fine-grained calcite was formed. Temperature of the erupted fluid tended to decrease during its mixing with the upper formation fluid and finally had the same temperature as the upper formation. From then on,the temperature was rather steady and fa-vored the growth of the coarse calcite. Due to this character of the temperature variation of the episodic fluid flow,we can use the homogenous temperature of the FIA of the coarse calcite to date the forma-tion and the destruction time of the Majiang ancient oil reservoir. Episodic fluid flow was known for its inhomogeneous trapping,which resulted in the failure of dating according to the burial history. But taking a close look at its temperature variation,we think that the latest stage of fluid flow,characterized by steady state temperature and grow of the coarser crystals,can be used for dating. It will be of great value if this method is proved to be effective. The formation and the destruction time of the Majiang ancient oil reservoir were dated to be in the Indosinian Period and the late Yanshan-early Hymalayan Period respectively. This conclusion is in great discrepancy with the common accepted idea that the Majiang ancient oil reservoir was formed and destroyed during the Cal

关键词： Majiang ancient oil reservoir episodic fluid flow marine carbonate rocks superimposed basin

Designing Drill-in Fluids by Using Ideal Packing Technique

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petroleum Science 2007年第2期4卷 44-51页

作者： Feng Wenqiang and Yan Jienian (School of petroleum Engineering, china university of petroleum, beijing 102.49, china) School of petroleum Engineering China University of PetroleumBeijing102249China

Selecting bridging agents properly is a critical factor in designing non-damaging or low-damaging drill-in fluids. Historically, Abrams' rule has been used for this purpose. However, Abrams' rule only addresses the size of particle required to initiate a bridge. The rule does not give an optimum size nor an ideal packing sequence for minimizing fluid invasion and optimizing sealing. This paper elaborates an ideal packing approach to solving the sealing problem by sealing pores with different sizes, especially those large pores which usually make dominant contribution to permeability and thereby effectively preventing the solids and filtrate of drill-in fluids from invading into formations, compared with the conventionally used techniques. Practical software has been developed to optimize the blending proportion of several bridging agents, so as to achieve ideal packing effectiveness. The method and its use in selecting the best blending proportion of several bridging agents are also discussed in this paper. A carefully designed drill-in fluid by using the ideal packing technique (named the IPT fluid) for offshore drilling operations at the Weizhou Oilfield, Nanhai West Company, CNOOC is presented. The near 100% return permeabilities from the dynamic damage tests using reservoir cores demonstrated the excellent bridging effect provided by this drill-in fluid.

关键词： Drill-in fluid particle size distribution ideal packing theory dynamic damage test formation damage control

Non-Darcy flow in oil accumulation (oil displacing water) and relative permeability and oil saturation characteristics of low-permeability sandstones

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petroleum Science 2010年第1期7卷 20-30页

作者： Zeng Jianhui Cheng Shiwei Kong Xu Guo Kai Wang Hongyu State Key Laboratory of petroleum resources and Prospecting China University of Petroleum Beijing 102249 China School of natural resources and information technology China University of Petroleum Beijing 102249 China CNPC Greatwall Drilling Company Beijing 100101 China

Hydrocarbon resources in low-permeability sandstones are very abundant and are extensively distributed. Low-permeability reservoirs show several unique characteristics, including lack of a definite trap boundary or caprock, limited buoyancy effect, complex oil-gas-water distribution, without obvious oil-gas-water interfaces, and relatively low oil （gas） saturation. Based on the simulation experiments of oil accumulation in low-permeability sandstone （oil displacing water）, we study the migration and accumulation characteristics of non-Darcy oil flow, and discuss the values and influencing factors of relative permeability which is a key parameter characterizing oil migration and accumulation in low-permeability sandstone. The results indicate that： 1） Oil migration （oil displacing water） in low- permeability sandstone shows non-Darcy percolation characteristics, and there is a threshold pressure gradient during oil migration and accumulation, which has a good negative correlation with permeability and apparent fluidity; 2） With decrease of permeability and apparent fluidity and increase of fluid viscosity, the percolation curve is closer to the pressure gradient axis and the threshold pressure gradient increases. When the apparent fluidity is more than 1.0, the percolation curve shows modified Darcy flow characteristics, while when the apparent fluidity up＂ non-Darcy percolation curve; 3） Oil-water is less than 1.0, the percolation curve is a ＂concave- two-phase relative permeability is affected by core permeability, fluid viscosity, apparent fluidity, and injection drive force; 4） The oil saturation of low- permeability sandstone reservoirs is mostly within 35%-60%, and the oil saturation also has a good positive correlation with the permeability and apparent fluidity.

关键词： Non-Darcy flow relative permeability oil saturation low-permeability sandstone

ALLOYING BEHAVIOUR OF Ca IN STEEL 58CrV

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Acta Metallurgica Sinica(English Letters) 1992年第6期5卷 449-453页

作者： LU Feng CAO Fengyu LI Chengji university of Science and technology beijing,beijing,chinaZHANG Yongxiang CHEN Yonggang beijing Institute of Machine Tools,beijing,china faculty of Metallograph,university of Science and technology beijing,beijing 100083,china beijing Univ of Science and Technology Beijing China

Effect of Ca on hardenability and CCT diagram of steel 58CrV has been investigated by means of end-quenching and thermal *** addition of 0.006 wt-%Ca to the steel may improve the hardenability,reduce the critical cooling rate of transformation of pearlite or bainite under continuous cooling and increase the M_*** analysis showed that Ca segre- gates markedly along austenitie grain boundaries,and accelecrates the segregation of C,Cr and *** is believed that besides towards deoxidizing and desulphurizing as well as improving sulphide morphology,a trace of Ca in steel 58CrV behaves towards microalloying.

关键词： Ca steel 58CrV microalloying hardenability CCT diagram

Study on forward modeling of through-casing resistivity logging

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Science china Earth Sciences 2008年第S2期51卷 207-211页

作者： GAO Jie1,LIU FuPing2,BAO DeZhou3,CHENG Xi3 & ZHANG YuLing4 1 china university of petroleum,beijing 102.49,china 2 beijing Institute of Graphic Communication,beijing 102600,china 3 china petroleum Logging CO. LTD.,Xi’an 710021,china 4 china National Logging Corporation,beijing 100101,china china Univ Petr Beijing 102249 Peoples R China beijing Inst Graph Commun Beijing 102600 Peoples R China china Petr Logging CO LTD Xian 710021 Peoples R China china Natl Logging Corp Beijing 100101 Peoples R China

Through-casing resistivity logging (TCRL) is a new kind of logging method for formation evaluation,reservoir monitoring and saturation changes tracking. In this paper,the basic principle of TCRL is de-tailed,and the modified transmission line equation method (MTLEM) is first proposed in china. The MTLEM has been employed to simulate the responses of TCRL,on the basis of which,the effects of formation resistivity,cement and casing on the responses of TCRL are analyzed,and the signals in-duced in different formations are also calculated,which can help the design of TCRL tool and data processing and interpretation in china.

关键词： through-casing resistivity logging (TCRL) modified transmission line equation method (MTLEM) casing cement sheath

Stabilization of Chaotic Time Series by Proportional Pulse in the System Variable Based on Genetic Algorithm

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 228-229页

作者： Qing Li Deling Zheng Jianlong Zhou(information Engineering School, university of Science and technology beijing, beijing 100083, china)(Handan iron and Steel Co., Handan 056015, china) information Engineering School University of Science and Technology Beijing Beijing 100083 China Handan Iron and Steel Co. Handan 056 015 China

The PPSV (Proportional Pulse in the System Variable) algorithm is a convenient method for the stabilization of the chaotic time series. It does not require any previous knowledge of the system. The PPSV method also has a shortcoming, that is, the determination off. is a procedure by trial and error, since it lacks of optimization. In order to overcome the blindness, GA (Genetic Algorithm), a search algorithm based on the mechanics of natural selection and natural genetics, is used to optimize the λi The new method is named as GAPPSV algorithm. The simulation results show that GAPPSV algorithm is very efficient because the control process is short and the steady-state error is small.

关键词： stabilization chaotic time series genetic algorithm