• 期刊名称:岩土工程物理与数值模拟
  • 出版周期:季刊
  • 外文:Physical and Numerical Simulation of Geotechnical Engineering
  • ISSN:1838-3254
  • 出版单位:St. Plum –blossom Press (Australia )
  • 出版地:澳大利亚•墨尔本

浏览次数 1941次

上一期岩土第七期 / 刊出日期:2012-06-30下一期
目录
  • Experimental Study of Different Gas Drive Displace

    ZHOU Tiyao, CHENG Linsong, ZHANG Jian

    Porous medium, Carbon dioxide, Compressed air, Nitrogen gas, Displacement efficiency experiment
    398PDF摘要

    With laboratory experimental methods, most experimental studies are based on single displacing media, but few researchers studied the difference of different gas drive. Based on the mechanism survey of gas drive, with three kinds’ gas and drilling core of Jilin oilfield, the experiment studied the drive law in porous medium, and analysis the mechanism. The result shows that, as the gas permeability’s adding, the displacement efficiency increasing. In the same displace condition, carbon dioxide drive reached the best result, next is compressed air, nitrogen gas is the lowest. The displace result of the same core within different pressure condition indicated that, carbon dioxide drive’s displacement efficiency enhanced as the inlet pressure added, it’s correlated with the accession of carbon dioxide’s resolution, which makes the crude oil’s volume swell and viscosity reduction.

  • Digital Experiment Steam and Incondensable Gas-ass

    CHENG Linsong, JI Youjun

    Heavy oil, Steam-assisted gravity drainage, Steam, Incondensable gas-assisted gravity push, Numerical simulation
    372PDF摘要

    Numerical simulation method is applied to study the procedure of steam and incondensable gas-assisted gravity push (SAGP) on heavy oil, the parameters of the process, such as temperature and saturation distribution etc. are obtained, the simulation results are analyzed and compared with steam-assisted gravity drainage (SAGD) on the same condition, some conclusions are drawn as follows: (1) During the upward spreading of steam chamber, the vertical expanding speed of SAGD is quicker than SAGP, but its horizontal expanding speed is slower; (2) In this two technologies, the cumulative oil of SAGP is slightly lower than that of SAGD, the final residual oil in the steam chamber of SAGD is less than SAGP, but the cumulative oil-steam rate (OSR) of SAGP is larger than SAGD, namely, the economic effect of SAGP technology is better; (3) In the SAGP technology, when the proportion of incondensable gas is 20%, and other technology parameters are the same, the heat lost of SAGP is 79% of SAGD, OSR of SAGP is 0.03 higher than SAGD; (4) SAGP will be a more economical and prospected technology on heavy oil recovery.

  • Study and Application on Well Test Analysis of Low

    YANG Yongzhi, SHEN Pingping

    Daqing oilfield, Low permeability reservoir, Start-up pressure gradient, Homogeneous model, Composite model, Well test analysis
    383PDF摘要

    There are some reservoirs with character of low porosity, low permeability, low abundance of OOIP and low productivity in Daqing Chanyuan and outer regions. It is important to know the flow rule and characteristic of them. This paper sets up low permeability homogeneous and composite reservoir mathematic models by introducing start-up pressure gradient factor in flow equation, gets type curves of well-test interpretation, builds a set of method and software for Daqing low permeability reservoirs. By using the method and soft, some major factors including well bore storage, skin, permeability, mobility, start-up pressure and formation pressure can be gotten, which can provide some useful information on development and regulation of low permeability reservoirs.

  • Research on the Application of Unsaturated Soil Wa

    YANG Yong, XUE Qiang

    Unsaturated, Soil water characteristic curve, Numerical simulation, Sensitivity analysis
    382PDF摘要

    The soil water characteristic curve is very important to the controlling movement of the unsaturated soil water. Based on the former models, this paper is simulated with the numerical simulation on Gardner-Simmons and Brooks-Corey and Van-Genuchten. The numerical results show that the VG model has a perfect flexibility in the soil water. At the same time, saturated water content and saturated infiltrate coefficient and residual water content are analyzed and discussed by the sensitivity analysis. The analysis results show that saturated infiltrate coefficient in those parameters is the most intensive than other parameters. Research on the parameters of water movement law can offer theory foundation for the measurement of the basic parameters in the laboratory and on the site.

  • Research on the Influence of Soil Density on the P

    ZHANG Xuedong, ZHAO Chenggang

    Permeability coefficient, Unsaturated soil, Soil water characteristic curve, Void ratio
    388PDF摘要

    The permeability coefficient of unsaturated soil is a particularly important parameter in unsaturated soil mechanics, and its value is mainly determined by the mineral composition of soil particles, pore size distribution, and water content. Existing models for predicting the coefficient generally hypothesize that the soil structure is incompressible, and only the influence of water content on the coefficient has been taken into account. However, it is found that the density of a soil mass is easy to change with the variation of external loads or buried depth in practice, and ignoring the influence created by the density variation will lead to a decrease of construction safety. To take soil density into consideration when predicting the coefficient permeability of unsaturated soils, this paper presents a calculation method by modifying the model proposed by Van-Genuchten (1980) through the relationship between the soil water characteristic curve and soil density. The comparison between the calculation and experimental results illustrates its good applicability in predicting the permeability function of deformable unsaturated soils.

  • 385PDF摘要

    Because of the complicated structure of unsaturated soil, direct measurement of unsaturated hydraulic conductivity in the laboratory is a very difficult process. Therefore, the indirect methods for measuring unsaturated hydraulic conductivity are widely used in practice. This paper mainly introduces the development of indirect methods, moreover, analyzes and compares the advantages and disadvantages of them briefly.

  • Experiment Study for Coal and Gas Outburst Under D

    SUN Weiji, CAO Yaolin, LIANG Bing

    Coal and gas outburst, Three dimensional experiment, Coal methane pressure, Outburst intensity, Bread-crust structure
    374PDF摘要

    The three-dimensional experiment of coal and gas outburst is inspired by the similarity theory. This paper mainly focuses on the relationship between coal and gas outburst and coal methane pressure studied; and the relationship between coal outburst and stress without the effect of coal methane pressure. The experimental results indicate: the outburst intensity and outburst distance increases rapidity with the increase of coal methane pressure under the same forming pressure and three dimensional stress; the bread-crust structure is discovered in the outburst coal, and the outburst hole is ellipsoidal shape at low pressure, or is pear shape at higher pressure. The coal and gas outburst does not occur without the effect of coal methane pressure. The pore pressure declines rapidity in coal when three dimensional stresses is loaded, and its original state would be restored after the stress is released. The pore pressure is probably much larger than the original coal methane pressure under the one of three dimensional stresses is released when coal and gas outburst occurred.

  • Effects of Fluid-solid Coupling on Tunnel in a Sa

    ZHANG Chuancheng, LIU Jianjun

    Finite-difference method, Pore-pressure, Fluid-solid coupling, Numerical analysis
    380PDF摘要

    Sometimes water is very important in the tunnel stability analysis. So water factor should be considered if analysis the tunnel stability that is hydraulic coupled analysis. The result can be closed to the real through hydraulic coupled analysis for tunnel. As for now the three-dimensional continua fast Lagrangian analysis software FLAC3D is employed in the analysis. Using finite-difference method, water seepage fields before and after reservoir built were simulated and compared with the results, the author studied the effects of water-head change on ground water seepage in tunnel.

  • Fuzzy Risk Analysis on Recharge of Underground Res

    Fuzzy Risk Analysis on Recharge of Underground Res

    ZHAO Jian, ZHAO Zhongwei, CHEN Xiaobing
    377PDF摘要

    With the development of underground reservoir construction and the developed theory of risk analysis, underground reservoir risk analysis has come up with a good opportunity. This study mainly discusses the risks on recharge of underground reservoir. It takes model identification on the factors causing recharge risk, and makes a description on their interaction. With the principle of fuzzy comprehensive evaluation, it takes a fuzzy analysis on natural factors of recharge risk, and builds a mathematical model. At the end of the study, it simulates an underground reservoir near a river, and takes an analysis on its recharge risk. The simulation gets a conclusion that danger is existed with only natural recharge.

  • The Transport of Cr (Ⅵ) Through Landfill Liners at

    LUAN Maotian, LU Haijun, ZHANG Jinli

    Adsorptive amendments, Isotherm parameters, Pollutant transport, Landfill liners
    386PDF摘要

    The effect of temperature and pH on the isotherm parameters of Cr (Ⅵ) adsorption onto landfill liner containing granular activated carbon (GAC), or bentonite activated by acid was investigated. The results show the values of measured isotherm parameters (qm, b) for all soils increased linearly with an increase of temperature. The values of measured qm decreased significantly with an increase of acidic pH, but as pH increased sequentially, the trend became slow relatively; The values of measured b decrease linearly with increasing of pH. GAC and bentonite activated by hydrochloric acid are two potential materials for use as adsorptive amendments for trapping heavy metals in landfill liners. One-dimensional transport simulations for Cr (Ⅵ) were performed to evaluate the effect of granular activated carbon (GAC) and activated bentonite on landfill liners. The results of the simulations indicate that landfill liners containing GAC, or activated bentonite, significantly retard the transport of Cr (Ⅵ) relative to a conventional clay liner. Without considering effect of temperature and pH, the results of the simulations would estimate unreasonably the transport of pollutants.

  • Application Research of the Fluid-solid Coupling

    ZHANG Xiangyu, LIANG Bing, JIANG Liguo

    Mechanism of permeating grouting, The fluid-solid coupling model of grouting, An engineering example
    391PDF摘要

    The key of the pipe grouting technology is to make sure the best grouting radius. This article makes the fluid-solid coupling model of the slurry and soil used in the advanced small pipe grouting advanced support for soft rock tunnel, there is guiding significance for arranging small pipe ' grouting borehole, obtaining the relationship of radius of soil mass between grouting pressure and grout diffusion, finding the best grouting diffusion radius;It is useful in predicting the grouting range, calculating the amount of slurry exactly, avoiding loss of property and personnel caused by collapse induced by manual excavation effectively and it has obvious Social benefit.

  • The Influence of Grid Density on Analysis of Slope

    WANG Zegen, JIANG Xiaoyong

    Strength reduction finite element method, Grid model, Safety factor, Precision analysis
    382PDF摘要

    This thesis conducted the evaluation of slope grid models according to safety factor and computational time by ANSYS. During the division of slop grid, potential sliding surface was further subdivided on the basis of global model to achieve optimization of grid division. After analyzing the relative errors of safety factor and the correspondent computational time, it was shown that dividing the grid too rough would result in unreliable calculation, while making it much precise would need a long calculating time. To balance, it was suggested that the potential sliding surface of the model should be fixed in advance, and thus to divide the whole model by one tenth of the slope height, and lastly to partially refine the potential sliding surface with one third side length of the non-refined grid.

  • The Practice Research of Risk Assessment of ERM Im

    WEI Li

    Enterprise risk management (ERM), Risk assessment, Risk measurement, Petroleum exploration and production (E&P) corporation, Fuzzy analytic hierarchy process (FAHP), Residual risk
    384PDF摘要

    Enterprise-wide risk management (ERM) is becoming the world trend and millions of corporations have put ERM into practice; therefore they have accumulated the best practice and theory basis which are applicable within the same industry. Whereas for the Chinese petroleum exploration and production (E&P) corporations, ERM can be a unique process by reason of the specific risk assessment. The essay is aimed to establish the practice system of the risk assessment of the petroleum exploration and development corporations by demonstrating the process and methods of the risk assessment in those corporations and bringing into the systemic risks assessment the fuzzy analytic hierarchy process and synthesis mark of risks. The analysis of the essay found a foothold the characteristics of the E&P corporations, based on COSO-ERM framework and consulted ERM Guidance of State-owned Enterprises.

  • Research on Flow Mechanism of Fishbone Well in Hea

    ZHANG Yingchun, ZHAO Chunming, TONG Kaijun, ZHOU F

    Flow mechanism, Bohai bay, Heavy oil field, Fishbone well, Ultimate recovery efficiency
    393PDF摘要

    Bohai Bay heavy oil fields are characterized by low productivity. According to above character, the heavy oil area of SZ 36-1 oilfield is chosen for a pilot area which aimed at improving both well productivity and ultimate recovery efficiency. Based on the existing inverted nine-spot pattern, five multilateral wells are located in the stably distributed and relatively thicker pay zones where put into production along with those existing directional wells. In this paper, we research on the mechanism of the heavy oil flow in porous medium. Firstly, based on analyzing the mathematical characterization of horizontal segment and branch, the production model of the symmetrical and unsymmetrical fishbone well is established using the principle of potential superposition and infinitesimal congruence, and involving the interference between branches. Secondly, using the above fishbone well mode design of fishbone well is optimized, including the length and number of benches, the distance between horizontal wall and branch, and the well is optimized on account of the well network. These five fishbone well were successfully exploited in Bohai bay heavy oilfield, which obtained satisfactory exploitation effect. The productivity of the fishbone wells is as high as 90~150 m3/d, which is 6~8 times of that a directional well. Reservoir simulation result shows that the pilot area’s ultimate recovery efficiency increment would reach as much as 4%. The exploitation of these five fishbone well in pilot area made a successful example to exploit heavy oilfields. The project has now been extended in other heavy oilfields in Bohai bay. Twenty-eight fishbone wells have been put into production. According to the exploitation effect, it not only could enhance the production, but also could enhance ultimate recovery efficiency. The development pattern combining the direction well with the fishbone well is an efficient pattern to exploit heavy oilfields.

  • Research on Flow Mechanism of Fishbone Well in Hea

    ZHANG Yingchun, ZHAO Chunming, TONG Kaijun, ZHOU F

    Flow mechanism, Bohai bay, Heavy oil field, Fishbone well, Ultimate recovery efficiency
    381PDF摘要

    Bohai Bay heavy oil fields are characterized by low productivity. According to above character, the heavy oil area of SZ 36-1 oilfield is chosen for a pilot area which aimed at improving both well productivity and ultimate recovery efficiency. Based on the existing inverted nine-spot pattern, five multilateral wells are located in the stably distributed and relatively thicker pay zones where put into production along with those existing directional wells. In this paper, we research on the mechanism of the heavy oil flow in porous medium. Firstly, based on analyzing the mathematical characterization of horizontal segment and branch, the production model of the symmetrical and unsymmetrical fishbone well is established using the principle of potential superposition and infinitesimal congruence, and involving the interference between branches. Secondly, using the above fishbone well mode design of fishbone well is optimized, including the length and number of benches, the distance between horizontal wall and branch, and the well is optimized on account of the well network. These five fishbone well were successfully exploited in Bohai bay heavy oilfield, which obtained satisfactory exploitation effect. The productivity of the fishbone wells is as high as 90~150 m3/d, which is 6~8 times of that a directional well. Reservoir simulation result shows that the pilot area’s ultimate recovery efficiency increment would reach as much as 4%. The exploitation of these five fishbone well in pilot area made a successful example to exploit heavy oilfields. The project has now been extended in other heavy oilfields in Bohai bay. Twenty-eight fishbone wells have been put into production. According to the exploitation effect, it not only could enhance the production, but also could enhance ultimate recovery efficiency. The development pattern combining the direction well with the fishbone well is an efficient pattern to exploit heavy oilfields.

  • Experiment on Ultrasonic Influence on CH3CCl2F Gas

    SUN Shicai

    Ultrasonic, CH3CCl2F gas hydrate, Nucleation
    377PDF摘要

    This work reports the influence of ultrasonic on the nucleation of gas hydrates. Experiments were carried out through the unique setup with a 15 kHz and 1000W ultrasonic system. Firstly, the influence of the different positions of the probe in the liquids on nucleation was investigated. Secondly, the comparison of the results at different supercooling was performed. The results show CH3CCl2F gas hydrates nucleation occurs almost simultaneously when ultrasonic was employed and less depends on the supercooling degrees. However, the growth time decreases with the supercooling increase. Energy consumption is lower under the same conditions with the probe at the interface. Based on these results, the mechanism of the influence of ultrasonic on CH3CCl2F nucleation was discussed, which suggests the reaction possibly takes place through two main pathways: free radical nucleation and supercritical nucleation.

  • Casing Damage Mechanism Caused By Seepage and its

    HUANG Xiaolan, XIONG Jun, WANG Xiqiang

    Casing damage, Seepage, Fluid-solid coupling, Mechanism, Numerical simulation
    372PDF摘要

    Along with the adoption of high pressure water injection, the casing damage will become more and more serious in the developing time. From the process of oilfield production, it can be concluded that casing damage is closely related to seepage field changes. From the types of mechanical deformation, casing damage can be categorized into three groups: extrusion failure, tensile failure and shear failure, which are all induced by seepage. Based on fluid-stress coupling theory, the mechanism of three types of casing damage is analyzed, and also the corresponding conceptual models are built separately. Finally a case study is given. The results show that seepage has great influence on casing damage, and it is necessary to consider the seepage field especially when numerical simulation with the high pressure water injection is done. It was clarified that with the different conceptual models all kinds of water injection pressure threshold limit values can be calculated, which can provide good governing theories and advices for controlling reasonable injection and production pressure and preventing casing damage.

  • Groundwater Numeric Simulation in the Water Source

    DU Chao, XIAO Changlai, LIANG Xiujuan

    Water source site, Shuangcheng City, Groundwater flow, Numeric simulation, GMS
    388PDF摘要

    The conceptual hydrogeologic model of the study area is generalized according to hydrogeologic conditions, and then the numeric model of groundwater flow is established by GMS software. Considering the influence of natural conditions and groundwater exploitation, six different schemes are determined to forecast groundwater level. The forecast results show that when pumping groundwater with designed exploitation quantity, the maximum central drawdown will not exceed the maximum permitted drawdown after 10 years in the new water source site.

  • A Mathematical Model of Regional Population Networ

    ZHAO Huiyan, LIU Jianjun, DUAN Xiang

    Urban planning, Population forecast, Fluid mechanics, Porous media, Percolation theory
    384PDF摘要

    City population forecast is one of the most important works in urban master planning. The traditional methods to predict the city population are with strong subjectivity and in intense disorder. They often calculate certain population for several times and in the end get a larger population forecasting number than the real. In this paper, an effective percolation-theory based population-forecast method is proposed. The region with lots of cities and rural is viewed as porous media, the population migration in the region is viewed as fluid, cities and rural in the region are viewed as pore. A mathematical model of population flow network is established based on fractured percolation theory. Based on this model, city or regional population forecast can be easily calculated in a similar way as calculating the flow in porous media. Population flow density in different times can be easily got through by simulation. This new method will benefit the city population forecast application.

  • Study on Layer System Adjustment Methods in D18 Bl

    Yang Xiaoshuang

    Remaining oil, Layer system adjustment, Barrier, Low permeability, Injection water
    390PDF摘要

    In order to ease the contradiction between layers, layer system adjustment is applied in oilfield development and separated layer water flooding is realized well. This method is a major adjustment measure to improve development effects. D18 is a typical low-permeability oilfield and physical property is poor. Many problems are existed, such as apparent contradiction between layers, and poor development effects and so on. In this article, the physical property and thickness of barrier, injection profile, permeability contrast and remaining oil distribution are analyzed comprehensively. A reasonable method is also proposed. Much weakness which exists in the former methods is overcome. For example, factors are not comprehensive and accurately reflected. Poor thin layers are produced better. Invalid water injection and contradiction between layers is decreased. Development effects are improved eventually. It is a reference and guidance for other blocks which exists the same problem.

  • Experiment of Dynamic Leaching on Landfill Leachat

    DI Junzhen, LIU Jianjun

    Organic pollution, Dynamic leaching, Soil column experiment, Mathematical simulation

    To study generally landfill leachate’s transport law, analyze migration law and forecast concentration distribution of pollutant by scientific method. Transport mechanism of organic pollutant (CODCr) in landfill leachate was studied by the dynamic leaching experiment, Solving of one-dimensional mathematical model indicate that model curve and experiment curve of COD are consistent, its explain validity of mathematical model.

  • Dynamic Modeling of SFD Pressure Measurement Syste

    GU Zhiping, HE Xingsuo, FENG Ningsheng

    Squeeze-Film, Dynamic Modeling, Measurement System, Vibration, Theorem of kinetic energy

    To study the dynamic behaviors of the squeeze film dampers (SFD), it is vital to know the oil film pressures in the dampers. Considering the outer race length restriction, a system consisting of capillaries and mass-springs at the other large piston ends is proposed to measure the pressures. By relating the mass of the liquid in the capillaries as an additional mass to the piston mass at the end, a simplified model of a mass-(viscous) damping-stiffness system for the measurement device is established, and a new approach on indirect measurement of oil film pressure is provided and proven with the aid of the similar theory and theorem of kinetic energy.

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