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商品房空置及饱和问题 被引量:1
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作者 张元端 《上海房地》 2003年第6期32-34,共3页
关键词 空置房 房地产市场 “饱和度” 增长型周期 住宅需求量
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Effect of gas saturation on P-wave velocity in tight sandstone
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作者 Pan Bao-Zhi Zhou Wei-Yi +2 位作者 Guo Yu-Hang Fang Chun-Hui Zhang Li-Hua 《Applied Geophysics》 SCIE CSCD 2024年第3期487-495,617,共10页
By measuring the variation of the P-and S-wave velocities of tight sandstone samples under water saturation,it was confirmed that with the decrease in water saturation,the P-wave velocity first decreased and then incr... By measuring the variation of the P-and S-wave velocities of tight sandstone samples under water saturation,it was confirmed that with the decrease in water saturation,the P-wave velocity first decreased and then increased.The variation in velocity was influenced by the sandstone’s porosity.The commonly used Gassmann equation based on fluid substitution theory was studied.Comparing the calculated results with the measured data,it was found that the Gassmann equation agreed well with the measured data at high water saturation,but it could not explain the bending phenomenon of P-wave velocity at low saturation.This indicated that these equations could not accurately describe the relationship between fluid content and rock acoustic velocity.The reasons for this phenomenon were discussed through Taylor’s expansion.The coefficients of the fitting formula were calculated and verified by fitting the measured acoustic velocity changes of the cores.The relationship between P-wave velocity and saturation was discussed,which provides experimental support for calculating saturation using seismic and acoustic logging data. 展开更多
关键词 Tight sandstone Saturation model Reservoir parameters Acoustic wave measurement
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Establishment and application of logging saturation interpretation equation in vuggy reservoirs 被引量:3
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作者 孙文杰 李宁 +2 位作者 武宏亮 王克文 张宫 《Applied Geophysics》 SCIE CSCD 2014年第3期257-268,350,共13页
Vuggy reservoirs are the most common, albeit important heterogeneous carbonate reservoirs in China. However, saturation calculations using logging data are not well developed, whereas Archie method is more common. In ... Vuggy reservoirs are the most common, albeit important heterogeneous carbonate reservoirs in China. However, saturation calculations using logging data are not well developed, whereas Archie method is more common. In this study, electrical conduction in a vuggy reservoir is theoretically analyzed to establish a new saturation equation for vuggy reservoirs. We found that vugs have a greater effect on saturation than resistivity, which causes inflection in the rock-electricity curve. Using single-variable exPeriments, we evaluated the effects of rug size, vug number, and vug distribution on the rock-electricity relation. Based on the general saturation model, a saturation equation for vuggy reservoirs is derived, and the physical significance of the equation parameters is discussed based on the seepage-electricity similarity. The equation parameters depend on the pore structure, and vugs and matrix pore size distribution. Furthermore, a method for calculating the equation parameters is proposed, which uses nuclear magnetic resonance (NMR) data to calculate the capillary pressure curve. Field application of the proposed equation and parameter derivation method shows good match between calculated and experimental results, with an average absolute error of 5.8%. 展开更多
关键词 Vuggy reservoir SATURATION general solution saturation equation capillary pressure capillary pressure curve NMR rock electricity.
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Percolation Network Modeling of Electrical Properties of Reservoir Rock* 被引量:2
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作者 王克文 孙建孟 +1 位作者 关继腾 苏远大 《Applied Geophysics》 SCIE CSCD 2005年第4期223-229,共7页
Based on the percolation network model characterizing reservoir rock's pore structure and fluid characteristics, this paper qualitatively studies the effects of pore size, pore shape, pore connectivity, and the amoun... Based on the percolation network model characterizing reservoir rock's pore structure and fluid characteristics, this paper qualitatively studies the effects of pore size, pore shape, pore connectivity, and the amount of micropores on the I - Sw curve using numerical modeling. The effects of formation water salinity on the electrical resistivity of the rock are discussed. Then the relative magnitudes of the different influencing factors are discussed. The effects of the different factors on the I - Sw curve are analyzed by fitting simulation results. The results show that the connectivity of the void spaces and the amount of micropores have a large effect on the I - S, curve, while the other factors have little effect. The formation water salinity has a large effect on the absolute resistivity values. The non-Archie phenomenon is prevalent, which is remarkable in rocks with low permeability. 展开更多
关键词 rock resistivity saturation exponent network modeling reservoir characteristics.
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Geophysical monitoring technology for CO_2 sequestration 被引量:1
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作者 马劲风 李琳 +6 位作者 王浩璠 谭明友 崔世凌 张云银 曲志鹏 贾凌云 张树海 《Applied Geophysics》 SCIE CSCD 2016年第2期288-306,417,418,共21页
Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniq... Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation. 展开更多
关键词 Carbon capture and storage geophysical monitoring 4D seismic monitoring CO2 saturation reservoir pressure
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Detection of gas hydrate sediments using prestack seismic AVA inversion 被引量:1
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作者 张如伟 李洪奇 +2 位作者 张宝金 黄捍东 文鹏飞 《Applied Geophysics》 SCIE CSCD 2015年第3期453-464,470,共13页
Bottom-simulating reflectors (BSRs) in seismic profile always indicate the bottom of gas hydrate stability zone, but is difficult to determine the distribution and features of gas hydrate sediments (GHS). In this stud... Bottom-simulating reflectors (BSRs) in seismic profile always indicate the bottom of gas hydrate stability zone, but is difficult to determine the distribution and features of gas hydrate sediments (GHS). In this study, based on AVA forward modeling and angle-domain common-image gathers we use prestack AVA parameters consistency inversion in predicting gas hydrate sediments in the Shenhu area at northern slope of South China Sea, and obtain the vertical and lateral features and saturation of GHS. 展开更多
关键词 Gas hydrate BSR Prestack inversion SATURATION
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Calculation of saturation in carbonate reservoirs based on electrical efficiency 被引量:2
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作者 李雄炎 秦瑞宝 +1 位作者 刘春成 毛志强 《Applied Geophysics》 SCIE CSCD 2014年第2期215-222,254,共9页
We derived an equation for saturation in carbonate reservoirs based on the electrical efficiency model in the case of lacking core data. Owing to the complex pore structure and strong heterogeneity in carbonate reserv... We derived an equation for saturation in carbonate reservoirs based on the electrical efficiency model in the case of lacking core data. Owing to the complex pore structure and strong heterogeneity in carbonate reservoirs, the relation between electrical efficiency and water porosity is either complex or linear. We proposed an electrical efficiency equation that accounts for the relation between electrical efficiency and water porosity. We also proposed a power-law relation between electrical efficiency and deep-formation resistivity and analyzed the factors controlling the error in the water saturation computations. We concluded that the calculation accuracy of the electrical efficiency is critical to the application of the saturation equation. The saturation equation was applied to the carbonate reservoirs of three wells in Iraq and Indonesia. For relative rock electrical efficiency error below 0.1, the water saturation absolute error is also below 0.1. Therefore, we infer that the proposed saturation equation generally satisfies the evaluation criteria for carbonate reservoirs. 展开更多
关键词 Rock electrical efficiency CARBONATE SATURATION functional relationship error analysis
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The analysis of frequency-dependent characteristics for fluid detection: a physical model experiment 被引量:2
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作者 陈双全 李向阳 王尚旭 《Applied Geophysics》 SCIE CSCD 2012年第2期195-206,235,236,共14页
According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a hi... According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a high-frequency bright spot as the amplitude energy shifts. However, it is a low-frequency shadow for the Class III AVO reservoirs saturated with hydrocarbons. In this paper, we verified the high-frequency bright spot results of Chapman for the Class I AVO response using the frequency-dependent analysis of a physical model dataset. The physical model is designed as inter-bedded thin sand and shale based on real field geology parameters. We observed two datasets using fixed offset and 2D geometry with different fluid- saturated conditions. Spectral and time-frequency analyses methods are applied to the seismic datasets to describe the response characteristics for gas-, water-, and oil-saturation. The results of physical model dataset processing and analysis indicate that reflection wave tuning and fluid-related dispersion are the main seismic response characteristic mechanisms. Additionally, the gas saturation model can be distinguished from water and oil saturation for Class I AVO utilizing the frequency-dependent abnormal characteristic. The frequency-dependent characteristic analysis of the physical model dataset verified the different spectral response characteristics corresponding to the different fluid-saturated models. Therefore, by careful analysis of real field seismic data, we can obtain the abnormal spectral characteristics induced by the fluid variation and implement fluid detection using seismic data directly. 展开更多
关键词 Frequency-dependent characteristic fluid detection time-frequency analysis attenuation and dispersion physical model
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Changes in Violaxanthin Deepoxidase Activity and Unsaturation of Thylakoid Membrane Lipids in Indica and Japonica Rice Under Chilling Condition and Strong Light 被引量:1
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作者 季本华 曹云英 +3 位作者 谢焕松 朱素琴 马强 焦德茂 《Acta Botanica Sinica》 CSCD 2003年第9期1063-1070,共8页
To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under ... To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light. 展开更多
关键词 thylakoid membrane lipids xanthophyll cycle violaxanthin deepoxidase Arrhenius plotting RICE
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Visualization of uncertainty associated with spatial prediction of continuous variables using HSI color model:a case study of prediction of pH for topsoil in peri-urban Beijing,China 被引量:1
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作者 檀满枝 陈杰 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第4期319-322,共4页
Hue-Saturation-Intensity (HSI) color model, a psychologically appealing color model, was employed to visualize uncertainty represented by relative prediction error based on the case of spatial prediction of pH of to... Hue-Saturation-Intensity (HSI) color model, a psychologically appealing color model, was employed to visualize uncertainty represented by relative prediction error based on the case of spatial prediction of pH of topsoil in the peri-urban Beijing. A two-dimensional legend was designed to accompany the visualization-vertical axis (hues) for visualizing the predicted values and horizontal axis (whiteness) for visualizing the prediction error. Moreover, different ways of visualizing uncertainty were briefly reviewed in this paper. This case study indicated that visualization of both predictions and prediction uncertainty offered a possibility to enhance visual exploration of the data uncertainty and to compare different prediction methods or predictions of totally different variables. The whitish region of the visualization map can be simply interpreted as unsatisfactory prediction results, where may need additional samples or more suitable prediction models for a better prediction results. 展开更多
关键词 Hue-Saturation-Intensity color model spatial prediction UNCERTAINTY VISUALIZATION
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Fe_(75)Zr_3Si_(13)B_9 magnetic materials prepared by spark plasma sintering 被引量:2
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作者 王兴华 王葛 +3 位作者 朱玉英 鲍金峰 杜雄飞 李强 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第3期712-717,共6页
Fe75Zr3Si13B9 magnetic amorphous powders were fabricated by mechanical alloying. Bulk amorphous and nanocrystalline alloys with 20 mm in diameter and 7 mm in height were fabricated by the spark plasma sintering techno... Fe75Zr3Si13B9 magnetic amorphous powders were fabricated by mechanical alloying. Bulk amorphous and nanocrystalline alloys with 20 mm in diameter and 7 mm in height were fabricated by the spark plasma sintering technology at different sintering temperatures. The phase composition, glass transition temperature (Tg), onset crystallization temperature (Tx), peak temperature (Tp) and super-cooled liquid region (ΔTx) of Fe75Zr3Si13B9 amorphous powders were analyzed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The phase transition, microstructure, mechanical properties and magnetic performance of the bulk alloys were discussed with X-ray diffractometer, scanning electron microscope (SEM), Gleeble 3500 and vibration sample magnetometer (VSM), respectively. It is found that with the increase in the sintering temperature at the pressure of 500 MPa, the density, compressive strength, micro-hardness and saturation magnetization of the sintering samples improved significantly, the amorphous phase began to crystallize gradually. Finally, the desirable amorphous and nanocrystalline magnetic materials at the sintering temperature of 863.15 K and the pressure of 500 MPa have a density of 6.9325 g/cm3, a compressive strength of 1140.28 MPa and a saturation magnetization of 1.28 T. 展开更多
关键词 mechanical alloying amorphous and nanocrystalline alloys saturation magnetization spark plasma sintering
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Structure and magnetic properties of RFe_7Mn_4Ti compounds with R=Y, Tb, Dy,Ho, and Er
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作者 杨石强 林萍华 +2 位作者 盛晓波 董寅生 杨素萍 《Journal of Southeast University(English Edition)》 EI CAS 2003年第2期146-148,共3页
The effect of Mn substitution for partial Fe in RFe 11Ti on structure and magnetic properties of compounds was researched. RFe 7Mn 4Ti samples (R=Y,Tb,Dy,Ho,Er) were prepared by means of vacuum arc-melting and s... The effect of Mn substitution for partial Fe in RFe 11Ti on structure and magnetic properties of compounds was researched. RFe 7Mn 4Ti samples (R=Y,Tb,Dy,Ho,Er) were prepared by means of vacuum arc-melting and subsequent vacuum annealing. The structure and magnetic properties of RFe 7Mn 4Ti compounds were investigated by X-ray powder diffraction and magnetic measurements. The following conclusions were obtained: all the RFe tMn 4Ti compounds crystallize in the ThMn 12-type structure. The lattice constants and the unit-cell volume changed with the increase of atomic number for R=Y, Tb, Dy, Ho, and Er. The compensation characters appear for the DyFe 7Mn 4Ti and HoFe 7Mn 4Ti compounds, and the compensation temperatures were about 123 K and 90 K, respectively. The Curie temperature, the saturation magnetization, and saturation moment of RFe 7Mn 4Ti compounds were given. 展开更多
关键词 intermetallic compounds ThMn 12-type structure saturation magnetization rare earth
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ANALYSIS OF STRESS FIELD NEAR CRACK TIP BASED ON ELECTRIC SATURATION MODEL
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作者 戴隆超 王鑫伟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第3期176-181,共6页
Within the framework of nonlinear eleetroelasticity, the stress field near to the crack tip in an infinite piezoelectric media subject to a far field uniform loading is studied by using an electrical strip saturation ... Within the framework of nonlinear eleetroelasticity, the stress field near to the crack tip in an infinite piezoelectric media subject to a far field uniform loading is studied by using an electrical strip saturation model and the complex variable method. And the emphasis is placed on the stress field near to the crack tip. The obtained solutions show that the normalized stress components at an arbitrary point near to the crack tip are determined by the angle of the point. Moreover, the stress components are independent of the distance from the point to the ori- gin of the coordinate. The distributions of in-plane stress components near to the crack tip are analyzed based on numerical results for PZT-SH. Compared with some related solutions, results show that the solutions are valid. 展开更多
关键词 PIEZOELECTRICITY stress intensity factors crack tips electrical strip saturation model complex vari-able method
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Relationship between the transition frequency of local fluid flow and the peak frequency of attenuation 被引量:1
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作者 曹呈浩 张宏兵 +1 位作者 潘益鑫 滕新保 《Applied Geophysics》 SCIE CSCD 2016年第1期156-165,221,共11页
Local fluid flow(LFF) at the mesoscopic scale is the main dissipation mechanism of seismic waves in heterogeneous porous media within the seismic frequency band.LFF is easily influenced by the structure and boundary... Local fluid flow(LFF) at the mesoscopic scale is the main dissipation mechanism of seismic waves in heterogeneous porous media within the seismic frequency band.LFF is easily influenced by the structure and boundary conditions of the porous media,which leads to different behaviors of the peak frequency of attenuation.The associated transition frequency can provide detailed information about the trend of LFF;therefore,research on the transition frequency of LFF and its relationship with the peak frequency of the corresponding attenuation(i.e.,inverse of quality factor) facilitates the detailed understanding of the effect of inner structures and boundary conditions in porous media.In this study,we firstly obtain the transition frequency of fluid flux based on Biot's theory of poroelasticity and the fast Fourier transform algorithm in a sample containing one repeating unit cell(RUC).We then analyze changes of these two frequencies in porous media with different porous properties.Finally,we extend our analysis to the influence of the undrained boundary condition on the transition frequency and peak frequency in porous media with multiple RUCs.This setup can facilitate the understanding of the effect from the undrained boundary condition.Results demonstrate that these two frequencies have the same trend at low water saturation,but amplitude variations differ between the frequencies as the amount of saturation increases.However,for cases of high water saturation,both the trend and the amplitude variation of these two frequencies fit well with each other. 展开更多
关键词 Local fluid flow peak frequency transition frequency saturation boundary condition
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Effects of Temperature and Water Saturation on CO_2 Production and Nitrogen Mineralization in Alpine Wetland Soils 被引量:14
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作者 GAO Jun-Qin OUYANG Hua +2 位作者 XU Xing-Liang ZHOU Cai-Ping ZHANG Feng 《Pedosphere》 SCIE CAS CSCD 2009年第1期71-77,共7页
Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and... Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and 35 ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2 production and N mineralization under increasing temperatures from 5 to 35 ℃ with the same water saturation condition in the marsh soil (r2 > 0.49, P < 0.0001) and the peat soil (r2 > 0.38, P < 0.002), and a negative relationship with water saturation increasing at the same temperature, especially 25 and 35 ℃, in the marsh soil (r2 > 0.70, P < 0.009) and the peat soil (r2 > 0.61, P < 0.013). In conclusion, temperatures and water saturation could regulate the relationship between CO2 production and net N mineralization in the Tibetan alpine marsh and peat soils. 展开更多
关键词 CO2 production N mineralization TEMPERATURE water saturation WETLAND
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Salt-Water Transport in Unsaturated Soils Under Crop Planting: Dynamics and Numerical Simulation 被引量:7
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作者 XU Li-Gang YANG Jing-Song +1 位作者 ZHANG Qi LIU Guang-Ming 《Pedosphere》 SCIE CAS CSCD 2005年第5期634-640,共7页
A laboratory salt-water dynamics experiment using unsaturated soils in packed silt loam and clay soil columns withdifferent soil texture profiles and groundwater levels under crops were conducted to study the changes ... A laboratory salt-water dynamics experiment using unsaturated soils in packed silt loam and clay soil columns withdifferent soil texture profiles and groundwater levels under crops were conducted to study the changes of salt-waterdynamics induced by water uptake of crops and to propose the theoretical basis for the regulation and control of salt-water dynamics as well as to predict salinity levels. The HYDRUS 1D model was applied to simulate the one-dimensionalmovement of water and salt transport in the soil columns. The results showed that the salts mainly accumulated in theplow layer in the soil columns under crops. Soil water and salt both moved towards the plow layer due to soil waterabsorption by the crop root system. The salt contents in the column with lower groundwater were mostly greater thanthose with high groundwater. The water contents in the soil columns increased from top to the bottom due to plant rootwater uptake. The changes in groundwater level had little influence on water content of the root zone in the soil columnswith crop planting. Comparison between the simulated and the determined values showed that model simulation resultswere ideal, so it is practicable to do numerical simulation of soil salt and water transport by the HYDRUS 1D model.Furthermore, if the actual movement of salt and water in fields is to be described in detail, much work needs to be done.The most important thing is to refine the parameters and select precise boundary conditions. 展开更多
关键词 crop planting numerical simulation salt accumulation salt-water dynamics
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Structure and magnetic properties of RFe7Mn4Ti compounds with R=Y, Tb, Dy,Ho, and Er
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作者 杨石强 林萍华 +2 位作者 盛晓波 董寅生 杨素萍 《Journal of Southeast University(English Edition)》 EI CAS 2003年第2期146-148,共页
The effect of Mn substitution for partial Fe in RFe 11Ti on structure and magnetic properties of compounds was researched. RFe 7Mn 4Ti samples (R=Y,Tb,Dy,Ho,Er) were prepared by means of vacuum arc-melting and s... The effect of Mn substitution for partial Fe in RFe 11Ti on structure and magnetic properties of compounds was researched. RFe 7Mn 4Ti samples (R=Y,Tb,Dy,Ho,Er) were prepared by means of vacuum arc-melting and subsequent vacuum annealing. The structure and magnetic properties of RFe 7Mn 4Ti compounds were investigated by X-ray powder diffraction and magnetic measurements. The following conclusions were obtained: all the RFe tMn 4Ti compounds crystallize in the ThMn 12-type structure. The lattice constants and the unit-cell volume changed with the increase of atomic number for R=Y, Tb, Dy, Ho, and Er. The compensation characters appear for the DyFe 7Mn 4Ti and HoFe 7Mn 4Ti compounds, and the compensation temperatures were about 123 K and 90 K, respectively. The Curie temperature, the saturation magnetization, and saturation moment of RFe 7Mn 4Ti compounds were given. 展开更多
关键词 intermetallic compounds ThMn 12-type structure saturation magnetization rare earth
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Measurement of Two Phase Flow in Porous Medium Using High-resolution Magnetic Resonance Imaging 被引量:4
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作者 蒋兰兰 宋永臣 +4 位作者 刘瑜 杨明军 朱宁军 王晓静 豆斌林 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第1期85-93,共9页
Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique. The porous medium was a packed bed of glass beads. Spin echo multi seq... Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique. The porous medium was a packed bed of glass beads. Spin echo multi sequence was used to measure the distribution of CO2 and water in the porous medium. The intensity images show that the fluid distribution is non-uniform due to its viscosity and pore structure of porous medium. The velocity distribution of fluids is calculated from the saturation of water and porosity of porous medium. The experimental results show that fluid velocities vary with time and position. The capillary dispersion rate donated the effects of capillary, which was largest at water saturations of 0.45. The displacement process is different between in BZ-02 and BZ-2. The final water residual saturation depends on permeability and porosity. 展开更多
关键词 two phase flow porous medium magnetic resonance imaging SATURATION CO2 velocity DISPLACEMENT
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Anisotropy of Soil Hydraulic Properties Along Arable Slopes 被引量:4
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作者 JING Yuan-Shu ZHANG Bin +1 位作者 A. THIMM H. ZEPP 《Pedosphere》 SCIE CAS CSCD 2008年第3期353-362,共10页
The spatial variations of the soil hydraulic properties were mainly considered in vertical direction. The objectives of this study were to measure water-retention curves, θ(ψ), and unsaturated hydraulic conductivi... The spatial variations of the soil hydraulic properties were mainly considered in vertical direction. The objectives of this study were to measure water-retention curves, θ(ψ), and unsaturated hydraulic conductivity functions, K(ψ), of the soils sampled at different slope positions in three directions, namely, in vertical direction, along the slope and along the contour, and to determine the effects of sampling direction and slope position of two soil catenas. At the upper slope positions, the surface soils (0-10 cm) sampled in the vertical direction had a lower soil water content, 0, at a certain soil water potential (-1 500 kPa 〈 ψ 〈 -10 kPa) and had the greatest unsaturated hydraulic conductivity, K, at ψ 〉 -10 kPa. At the lower slope positions, K at ψ〉 -10 kPa was smaller in the vertical direction than in the direction along the slope. The deep soils (100 110 cm) had similar soil hydraulic properties in all the three directions. The anisotropic variations of the hydraulic properties of the surface soils were ascribed to the effects of natural wetting and drying cycles on the structural heterogeneity. These results suggested that the anisotropy of soil hydraulic properties might be significant in influencing soil water movement along the slope and need to be considered in modeling. 展开更多
关键词 slope hydrology spatial variation unsaturated hydraulic conductivity water-retention curve
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Digital core approach to the effects of clay on the electrical properties of saturated rocks using lattice gas automation 被引量:9
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作者 Yue Wen-Zheng Tao Guo +1 位作者 Chai Xi-Yuan Cui Dong-Zi 《Applied Geophysics》 SCIE CSCD 2011年第1期11-17,94,共8页
Clay has a significant influence on the relationship between resistivity index I and water saturation Sw (i.e, I-Sw relationship) of reservoir rocks because it complicates the current paths of these rocks. It is dif... Clay has a significant influence on the relationship between resistivity index I and water saturation Sw (i.e, I-Sw relationship) of reservoir rocks because it complicates the current paths of these rocks. It is difficult to reveal the physical mechanisms of these clay effects on the conductivities of various rocks by physical laboratory measurements because the pore structure, micro distribution and content of clay inside a rock can not be observed and controlled during the experiments. We present a digital rock approach to study these clay effects on the electrical transport properties of reservoir rocks at pore scale using lattice gas automation (LGA) method. The digital rock samples are constructed with the information of grain size distribution from SEM images of reservoir rocks. The LGA is then applied on these digital rocks fully saturated with fluids to simulate the electrical transport properties for revealing the effects of volume and distribution patterns of clay on the non-Archie behaviors of the I-Sw relationship. The very good agreement between the simulated results and the laboratory measurements clearly demonstrates the validity of the LGA in numerical research of rock physics. Based on these studies, a new model has been developed for quantitatively describing the relationship between the saturation exponent and the volume of clay (Vsh). This development may improve the evaluation for the fluid saturations in reservoir rocks. 展开更多
关键词 Lattice gas automation Digital rock non-Archie behavior of I-Sw relationship clay content
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