The Experts below are selected from a list of 10578 Experts worldwide ranked by ideXlab platform

Guanglong Sheng - One of the best experts on this subject based on the ideXlab platform.

  • a unified Apparent Porosity permeability model of organic porous media coupling complex pore structure and multi migration mechanism
    Advances in Geo-Energy Research, 2020
    Co-Authors: Guanglong Sheng, Hui Zhao, Jinghua Liu
    Abstract:

    Shale gas resources are widely distributed and abundant in China, which is an important field for strategic replacement and development of oil and gas resources. Shale gas reservoirs has adsorption gas, free gas. The structure of different scale media, such as organic pores, are difficult to describe. Therefore, flow behavior cannot be simulated by conventional method. In this paper, the micro-scale fluid migration in shale gas reservoirs was established in a single pore, which coupled surface diffusion, slip flow, and viscous flow. On this basis, the fractal scale relationship was applied to describe the distribution of pore radius, tortuosity, and surface roughness. Based on the comprehensive characterization of static structure haracteristics of porous media, such as pore size distribution, pore shapes, tortuosity and surface roughness, and the dynamic pore size influenced by various stresses, the Apparent Porosity/permeability model of organic matter considering single-phase multi-migration mechanism was established. The gas migration in organic porous media was analyzed with the Apparent Porosity/permeability model. The results show that the small pores in organic matter are the main storage space of gas (more than 95% of the gas is stored in pores less than 10 nm), and the large pores are gas flow channel. At the same time, the Apparent Porosity/permeability model combined with conventional Darcy equation can be used to describe the single-phase gas flow in shale gas reservoirs. Cited as :  Sheng, G., Su, Y., Zhao, H., Liu, J. A unified Apparent Porosity/permeability model of organic porous media: Coupling complex pore structure and multi-migration mechanism. Advances in Geo-Energy Research, 2020, 4(2): 115-125, doi: 10.26804/ager.2020.02.01

  • an analytical model to couple gas storage and transport capacity in organic matter with noncircular pores
    Fuel, 2020
    Co-Authors: Guanglong Sheng, Hui Zhao, Jinghua Liu, Farzam Javadpour, Chenchen Wang, Yuhui Zhou, Hui Wang
    Abstract:

    Abstract Scanning Electro Microscope (SEM) images illustrate the variety of possible pore shape in organic matter of shale reservoirs. The size of the pores with different geometries is at nanoscale (10–100 s nm), hence the ratio of wetted surface area to the volume of pores (specific surface area, SSA) is high. For the systems with high SSA the collisions between gas molecules and pore walls become significant, therefore, fluid flow is not dominantly controlled by the bulk flow, i.e., fluid-wall surface interaction becomes important. Most shale permeability models assume circular nanopores that results in poor prediction of permeability. We present a novel analytical Apparent Porosity and permeability model to model gas storage and permeability in shale gas reservoirs with noncircular nanopores. The SSA and the aspect ratio of height to the width of noncircular nanopores, were both used in our model to couple gas storage and transport capacity. We validated our model with permeability values calculated from pore network simulations of five shale samples from Jianghan Basin of China. The results showed that sharp edges in nanopores could dramatically affect permeability. For examples, the noncircularity deviation of gas flow in a rectangular nanopore is more than an equivalent nanopore with elliptical cross-section. The assumption of circular cross-section nanopores in estimating Apparent Porosity and permeability could impose up to 55% error depending on the pore geometry.

  • effect of microscale compressibility on Apparent Porosity and permeability in shale gas reservoirs
    International Journal of Heat and Mass Transfer, 2018
    Co-Authors: Guanglong Sheng, Farzam Javadpour
    Abstract:

    Abstract The pore network in shale reservoirs comprise of nanoporous organic matter (OM) and micron-size pores in inorganic material (iOM). Accurate gas transport models in shale must include gas slippage, Knudsen diffusion, surface diffusion, and sorption. The change in pore size due to the applied stress could consequently affect gas transport processes. In this study we a compression coefficient to characterize the influence of stress sensitivity on key parameters for gas transport. We consider separate stress response in nanoporous organic matter and iOM because of their different mechanical properties. The effects of compressibility on Apparent permeability of OM and iOM are analyzed at different pore sizes, pore pressures and for different gas compositions. Our results show that compressibility has a greater influence on the Apparent permeability of iOM than on OM when pore sizes are smaller than 10 nm, whereas compression has similar impact on Apparent permeability of both media when pore sizes are larger than 10 nm. With the same effective stress, lower pore pressure results in greater impair in permeability. We conducted a reservoir simulation study using conventional dual-continua model with our developed pressure dependent Porosity and permeability to showcase field implication of this study. This work is an important and timely investigation of the development of shale-reservoir-flow simulators.

Jinghua Liu - One of the best experts on this subject based on the ideXlab platform.

  • a unified Apparent Porosity permeability model of organic porous media coupling complex pore structure and multi migration mechanism
    Advances in Geo-Energy Research, 2020
    Co-Authors: Guanglong Sheng, Hui Zhao, Jinghua Liu
    Abstract:

    Shale gas resources are widely distributed and abundant in China, which is an important field for strategic replacement and development of oil and gas resources. Shale gas reservoirs has adsorption gas, free gas. The structure of different scale media, such as organic pores, are difficult to describe. Therefore, flow behavior cannot be simulated by conventional method. In this paper, the micro-scale fluid migration in shale gas reservoirs was established in a single pore, which coupled surface diffusion, slip flow, and viscous flow. On this basis, the fractal scale relationship was applied to describe the distribution of pore radius, tortuosity, and surface roughness. Based on the comprehensive characterization of static structure haracteristics of porous media, such as pore size distribution, pore shapes, tortuosity and surface roughness, and the dynamic pore size influenced by various stresses, the Apparent Porosity/permeability model of organic matter considering single-phase multi-migration mechanism was established. The gas migration in organic porous media was analyzed with the Apparent Porosity/permeability model. The results show that the small pores in organic matter are the main storage space of gas (more than 95% of the gas is stored in pores less than 10 nm), and the large pores are gas flow channel. At the same time, the Apparent Porosity/permeability model combined with conventional Darcy equation can be used to describe the single-phase gas flow in shale gas reservoirs. Cited as :  Sheng, G., Su, Y., Zhao, H., Liu, J. A unified Apparent Porosity/permeability model of organic porous media: Coupling complex pore structure and multi-migration mechanism. Advances in Geo-Energy Research, 2020, 4(2): 115-125, doi: 10.26804/ager.2020.02.01

  • an analytical model to couple gas storage and transport capacity in organic matter with noncircular pores
    Fuel, 2020
    Co-Authors: Guanglong Sheng, Hui Zhao, Jinghua Liu, Farzam Javadpour, Chenchen Wang, Yuhui Zhou, Hui Wang
    Abstract:

    Abstract Scanning Electro Microscope (SEM) images illustrate the variety of possible pore shape in organic matter of shale reservoirs. The size of the pores with different geometries is at nanoscale (10–100 s nm), hence the ratio of wetted surface area to the volume of pores (specific surface area, SSA) is high. For the systems with high SSA the collisions between gas molecules and pore walls become significant, therefore, fluid flow is not dominantly controlled by the bulk flow, i.e., fluid-wall surface interaction becomes important. Most shale permeability models assume circular nanopores that results in poor prediction of permeability. We present a novel analytical Apparent Porosity and permeability model to model gas storage and permeability in shale gas reservoirs with noncircular nanopores. The SSA and the aspect ratio of height to the width of noncircular nanopores, were both used in our model to couple gas storage and transport capacity. We validated our model with permeability values calculated from pore network simulations of five shale samples from Jianghan Basin of China. The results showed that sharp edges in nanopores could dramatically affect permeability. For examples, the noncircularity deviation of gas flow in a rectangular nanopore is more than an equivalent nanopore with elliptical cross-section. The assumption of circular cross-section nanopores in estimating Apparent Porosity and permeability could impose up to 55% error depending on the pore geometry.

Liu Jinghua - One of the best experts on this subject based on the ideXlab platform.

  • A unified Apparent Porosity/permeability model of organic porous media: Coupling complex pore structure and multi-migration mechanism
    Advances in Geo-Energy Research, 2020
    Co-Authors: Sheng Guanglong, Su Yuliang, Zhao Hui, Liu Jinghua
    Abstract:

     Shale gas resources are widely distributed and abundant in China, which is an important field for strategic replacement and development of oil and gas resources. Shale gas reservoirs has adsorption gas, free gas. The structure of different scale media, such as organic pores, are difficult to describe. Therefore, flow behavior cannot be simulated by conventional method. In this paper, the micro-scale fluid migration in shale gas reservoirs was established in a single pore, which coupled surface diffusion, slip flow, and viscous flow. On this basis, the fractal scale relationship was applied to describe the distribution of pore radius, tortuosity, and surface roughness. Based on the comprehensive characterization of static structure haracteristics of porous media, such as pore size distribution, pore shapes, tortuosity and surface roughness, and the dynamic pore size influenced by various stresses, the Apparent Porosity/permeability model of organic matter considering single-phase multi-migration mechanism was established. The gas migration in organic porous media was analyzed with the Apparent Porosity/permeability model. The results show that the small pores in organic matter are the main storage space of gas (more than 95% of the gas is stored in pores less than 10 nm), and the large pores are gas flow channel. At the same time, the Apparent Porosity/permeability model combined with conventional Darcy equation can be used to describe the single-phase gas flow in shale gas reservoirs.Cited as: Sheng, G., Su, Y., Zhao, H., Liu, J. A unified Apparent Porosity/permeability model of organic porous media: Coupling complex pore structure and multi-migration mechanism. Advances in Geo-Energy Research, 2020, 4(2): 115-125, doi: 10.26804/ager.2020.02.0

Hui Zhao - One of the best experts on this subject based on the ideXlab platform.

  • a unified Apparent Porosity permeability model of organic porous media coupling complex pore structure and multi migration mechanism
    Advances in Geo-Energy Research, 2020
    Co-Authors: Guanglong Sheng, Hui Zhao, Jinghua Liu
    Abstract:

    Shale gas resources are widely distributed and abundant in China, which is an important field for strategic replacement and development of oil and gas resources. Shale gas reservoirs has adsorption gas, free gas. The structure of different scale media, such as organic pores, are difficult to describe. Therefore, flow behavior cannot be simulated by conventional method. In this paper, the micro-scale fluid migration in shale gas reservoirs was established in a single pore, which coupled surface diffusion, slip flow, and viscous flow. On this basis, the fractal scale relationship was applied to describe the distribution of pore radius, tortuosity, and surface roughness. Based on the comprehensive characterization of static structure haracteristics of porous media, such as pore size distribution, pore shapes, tortuosity and surface roughness, and the dynamic pore size influenced by various stresses, the Apparent Porosity/permeability model of organic matter considering single-phase multi-migration mechanism was established. The gas migration in organic porous media was analyzed with the Apparent Porosity/permeability model. The results show that the small pores in organic matter are the main storage space of gas (more than 95% of the gas is stored in pores less than 10 nm), and the large pores are gas flow channel. At the same time, the Apparent Porosity/permeability model combined with conventional Darcy equation can be used to describe the single-phase gas flow in shale gas reservoirs. Cited as :  Sheng, G., Su, Y., Zhao, H., Liu, J. A unified Apparent Porosity/permeability model of organic porous media: Coupling complex pore structure and multi-migration mechanism. Advances in Geo-Energy Research, 2020, 4(2): 115-125, doi: 10.26804/ager.2020.02.01

  • an analytical model to couple gas storage and transport capacity in organic matter with noncircular pores
    Fuel, 2020
    Co-Authors: Guanglong Sheng, Hui Zhao, Jinghua Liu, Farzam Javadpour, Chenchen Wang, Yuhui Zhou, Hui Wang
    Abstract:

    Abstract Scanning Electro Microscope (SEM) images illustrate the variety of possible pore shape in organic matter of shale reservoirs. The size of the pores with different geometries is at nanoscale (10–100 s nm), hence the ratio of wetted surface area to the volume of pores (specific surface area, SSA) is high. For the systems with high SSA the collisions between gas molecules and pore walls become significant, therefore, fluid flow is not dominantly controlled by the bulk flow, i.e., fluid-wall surface interaction becomes important. Most shale permeability models assume circular nanopores that results in poor prediction of permeability. We present a novel analytical Apparent Porosity and permeability model to model gas storage and permeability in shale gas reservoirs with noncircular nanopores. The SSA and the aspect ratio of height to the width of noncircular nanopores, were both used in our model to couple gas storage and transport capacity. We validated our model with permeability values calculated from pore network simulations of five shale samples from Jianghan Basin of China. The results showed that sharp edges in nanopores could dramatically affect permeability. For examples, the noncircularity deviation of gas flow in a rectangular nanopore is more than an equivalent nanopore with elliptical cross-section. The assumption of circular cross-section nanopores in estimating Apparent Porosity and permeability could impose up to 55% error depending on the pore geometry.

Annamaria Dobradi - One of the best experts on this subject based on the ideXlab platform.

  • correlation of strength to Apparent Porosity of geopolymers understanding through variations of setting time
    Construction and Building Materials, 2015
    Co-Authors: Ida Balczar, Tamas Korim, Annamaria Dobradi
    Abstract:

    Abstract The research focused on manufacturing a novel binding material system featured by adequate strength. The molar ratio of the components was optimised to reach this favourable property together with a cost-cutting reduction of heat treatment time. Compressive strength and the relation of Apparent Porosity to setting time were studied and evaluated. Four sets of samples were prepared, and the SiO 2 /Al 2 O 3 as well as the Na 2 O/Al 2 O 3 molar ratios were varied over a wide range. As a result, the compressive strength of the samples (51.3 and 81.4 MPa at 7 and 28 days age, respectively) surpassed the highest strength class of Portland cements (52.5 MPa). There was a strong relationship between the uncertainty of Apparent Porosity determination and setting time, furthermore, the setting time was controlled primarily by the alkaline concentration of the activating solution and secondly by the soluble silica or water contents.