The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Lianyang Zhang - One of the best experts on this subject based on the ideXlab platform.
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Aspects of rock Permeability
Frontiers of Structural and Civil Engineering, 2013Co-Authors: Lianyang ZhangAbstract:Effective evaluation of rock Permeability is required in different energy, engineering and environmental projects. Although much research has been conducted on rock Permeability, it is still one of the most difficult tasks for practicing rock engineers to accurately determine rock Permeability. Based on a comprehensive literature review, this paper outlines the key aspects of rock Permeability by presenting the representative values of the Permeability of different rocks, describing the empirical and semi-empirical correlations for estimating the Permeability of rocks, and discussing the main factors affecting the Permeability of rocks. The factors discussed include stress, depth, temperature, and discontinuity intensity and aperture. This paper also highlights the scale effect on rock Permeability, interconnectivity of discontinuities, and anisotropy of rock Permeability. This paper provides the fundamental and essential information required for effective evaluation of rock Permeability.
Zhang Shao-jun - One of the best experts on this subject based on the ideXlab platform.
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A Productivity Prediction Equation Considering Rock Permeability Stress-Sensitivity in Low-Permeability Gas Reservoirs
Natural Gas Geoscience, 2008Co-Authors: Zhang Shao-junAbstract:Pore pressure decreases,effective stress increases,and Permeability declines due to matrix and pore compression as gas produces in low-Permeability gas reservoirs.This affects the deliverability of low-Permeability gas reservoirs.Based on Darcy flow law and the universal cognition that the rock Permeability varies with the effective stress exponentially,this paper presents a new equation considering rock Permeability stress-sensitivity for estimating the productivity in low-Permeability gas reservoirs.A case calculation with this new equation shows that considering Permeability stress-sensitivity in the prediction is necessary,especially for the high stress-sensitive low-Permeability gas reservoirs,and this will provide necessary reference to determining reasonable producing pressure drop and producing rate.
Jieru Wang - One of the best experts on this subject based on the ideXlab platform.
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Laboratory Measurement and Analysis of the Deteriorated Layer Permeability Coefficient of Soil-Cement Deteriorated in a Saline Environment
Materials, 2019Co-Authors: Junwei Su, Tu Lu, Jieru WangAbstract:The deterioration of soil-cement in a saline environment leads to a reduction in strength and an increase in Permeability. Effective methods of determining the deteriorated layer Permeability coefficient of soil-cement are currently lacking. A laboratory test method for measuring the Permeability coefficient of the deteriorated layer was proposed using the modified Permeability coefficient testing apparatus. According to the proposed method, the Permeability coefficient of the deteriorated layer could be obtained after testing the Permeability coefficient of the soil-cement specimen in acuring room and testing the equivalent Permeability coefficient and deterioration depth of the soil-cement specimen in a deteriorated environment. Using the marine dredger fill from Jiaozhou Bay as a case study, the deteriorated layer Permeability coefficients of soil-cements with different cement contents were tested. It turned out that the Permeability of the deteriorated layer increases with age. At the beginning of the curing age, higher cement content led to a smaller Permeability coefficient of the deteriorated layer of soil-cement. As the curing age increased, the deteriorated layer Permeability coefficient of the soil-cement with higher cement content increased. The evolution of the Permeability coefficient of a deteriorated layer with age can be formulated as the Logistic function. This study provides support for anti-Permeability designs of soil-cement structures in saline environments.
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Laboratory Measurement and Analysis of Deteriorated Layer Permeability Coefficient of Corroded Soil-Cement
2019Co-Authors: Junwei Su, Tu Lu, Jieru WangAbstract:The deterioration of soil-cement in corrosive environment leads to the reduction of strength and the increase of Permeability. Effective methods of determining deteriorated layer Permeability coefficient of soil-cement are currently lacking. A laboratory test method for Permeability coefficient of deteriorated layer was proposed using the modified Permeability coefficient testing apparatus. According to the proposed method, the Permeability coefficient of deteriorated layer can be obtained after testing the Permeability coefficient of the soil-cement specimen in curing room and the equivalent Permeability coefficient and deterioration depth of the soil-cement specimen in corrosion environment. Taking the marine dredger fill of Jiaozhou Bay for example, the deteriorated layer Permeability coefficients of soil-cements with different cement contents were tested. It turned out that the Permeability of deteriorated layer increases with the increase of age. At the beginning of curing age, larger cement content leads to smaller Permeability coefficient of the deteriorated layer of soil-cement. As the curing age increases, the deteriorated layer Permeability coefficient of the soil-cement with larger cement content becomes larger. The evolution of the Permeability coefficient of deteriorated layer with age can be formulated as the Logistic function. This study provides a support for anti-Permeability designs of soil-cement structures in corrosive environment.
Steven J Alexander - One of the best experts on this subject based on the ideXlab platform.
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vascular Permeability factor vascular endothelial cell growth factor mediated Permeability occurs through disorganization of endothelial junctional proteins
Journal of Biological Chemistry, 1998Co-Authors: Christopher G Kevil, Keith D Payne, Elizabeth Mire, Steven J AlexanderAbstract:Vascular Permeability factor/vascular endothelial growth factor stimulates endothelial proliferation, angiogenesis, and increased vascular Permeability in vivo. We investigated mechanisms of vascular Permeability factor-mediated endothelial monolayer Permeability changes in vitro. [14C]Albumin flux across endothelial monolayers was measured following a 90-min exposure to vascular Permeability factor (660 pM). Vascular Permeability factor increased albumin flux to 3.4 times that of control albumin flux. Endothelial monolayers were also incubated for 90 min with vascular Permeability factor plus Go6976 (10 nM), staurosporine (1 microM), wortmannin (10 nM), AG126 (1 and 2.67 microM), and PD98059 (20 microM). Vascular Permeability factor-mediated Permeability was not blocked by Go6976, an antagonist of "classical" protein kinase C, staurosporine, a pan-protein kinase C antagonist, nor wortmannin, a PI3-kinase blocker, but was blocked by incubation with AG126 or PD98059, inhibitors of mitogen-activated protein kinase activation. Immunofluorescent staining of the junctional proteins VE-cadherin and occludin showed a loss of these proteins from the endothelial junction that was prevented by co-incubation with AG126 or PD98059. These data demonstrate that vascular Permeability factor increases albumin Permeability across endothelial monolayers in vitro and suggests that Permeability increases through rearrangement of endothelial junctional proteins involving the mitogen-activated protein kinase signal transduction pathway.
Gang Lei - One of the best experts on this subject based on the ideXlab platform.
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A Fractal Model for the Stress-Dependent Permeability and Relative Permeability in Tight Sandstones
Journal of Canadian Petroleum Technology, 2015Co-Authors: Gang Lei, Pingchuan Dong, Shaohua Gai, Chao Zhao, Z.k. LiuAbstract:Stress-dependent Permeability and relative Permeability in porous media are important in petroleum-engineering fields. It has been shown that stress-dependent Permeability and relative Permeability play important roles in determination of flow characteristics for tight-sandstone porous media. In this work, novel predictive models for stress-dependent Permeability and relative Permeability in microporous media with lower Permeability are developed on the basis of fractal theory. The predictions of irreducible water saturation, normalized porosity, normalized Permeability, and the ratio Krw/Krg by the proposed model show a variation trend similar to that of the available experimental data. On the basis of the proposed normalized porosity and normalized Permeability model, it is found that the normalized porosity and Permeability decrease with effective stress, thus predicted results are in good agreement with former experiments. The proposed normalized porosity and normalized Permeability are expressed as a function of the effective stress, rock elastic modulus, microstructural parameters, and initial irreducible water saturation. The theoretical study of relative Permeability under stress demonstrates that wetting phase relative Permeability is related to the effective stress, microstructural parameters, and initial irreducible water saturation.
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Experimental Study on Stress Sensitivity of Ultra-Low Permeability Sandstones
Applied Mechanics and Materials, 2013Co-Authors: Hai Yong Zhang, Guo Hua Luan, Gang LeiAbstract:Ultra-low Permeability rocks have plenty of microfractures. The stress-dependent Permeability has a significant impact on the seepage. Previous studies are mainly on the Permeability variation with stress in low Permeability reservoir. But few are involved in ultralow Permeability cores. In this paper, the experiment of stress sensitive ultralow Permeability cores which are fabricated (both matrix cores and microfracture cores) is conducted. The experimental results shows that the Permeability of microfracture low Permeability cores which are fabricated increases greatly while the porosity of low Permeability cores is little affected. This indicates that the fabricated microfracture cores are in line with that of the real situations of fracture media reservoir. By comparison, the Permeability stress sensitive hysteresis degree of microfracture cores is not apparent and the Permeability recovery degree is high in the unloading cycle. This study is of great benefit to reveals the stress sensitivity features of ultralow Permeability reservoir
