Determination of Klinkenberg Permeability Conditioned to Pore-Throat Structures in Tight Formations

Liu, Guangfeng; Bai, Yaoxing; Fan, Zhixing; Gu, Da-Ming

doi:10.3390/en10101575

Cited by 13 publications

(8 citation statements)

References 22 publications

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“…Besides the previous findings associated with the Klinkenberg permeability and the slippage factor, the Klinkenberg permeability has been found to be linearly related to the under the aforementioned three experimental conditions, which shares similarity with the Klinkenberg permeability measured in tight oil formations [23]. Figure 5 shows the relationships between * and Klinkenberg permeability of samples 1-12 and samples 1-8 under high confining pressure condition, respectively.…”

Section: New Correlationssupporting

confidence: 76%

Experimental Determination of Gas Relative Permeability Considering Slippage Effect in a Tight Formation

et al. 2018

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In this paper, the gas relative permeability considering slippage effect has been experimentally examined under various experimental conditions (i.e., ambient, high confining pressure, and high temperature). Experimentally, Klinkenberg permeabilities of 12 core samples have been measured by using steady-state flow experiment. It has been found that the Klinkenberg permeability is independent of the experimental temperature and dramatically decreases as confining pressure is increasing. Furthermore, linear correlations have been newly developed between the Klinkenberg permeability and the gas-measured permeability under various conditions. Subsequently, the developed correlations are correspondingly applied to calibrate the gas relative permeability. It has been found that the gas relative permeability can be overestimated without consideration of the slippage effect, i.e., Klinkenberg effect. In addition, the newly developed correlations have been applied to analyze the sensitivity of gas-water relative permeability to gas-measured permeability, confining pressure, and temperature. It is demonstrated that mobile water greatly alleviates the gas relative permeability in comparison to irreducible water. Although an increased confining pressure simultaneously reduces the effective water phase and gas phase permeability, the gas relative permeability increases and the water relative permeability decreases as the confining pressure increases. It is attributed to the fact that the effective water phase permeability is more sensitive to the confining pressure. Given an elevated experimental temperature, the gas relative permeability is reduced while the water relative permeability is enhanced, implying the significance of temperature effect on gas-water relative permeability measurements.

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Section: New Correlationssupporting

confidence: 76%

Experimental Determination of Gas Relative Permeability Considering Slippage Effect in a Tight Formation

et al. 2018

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“…Mercury intrusion porosimetry (MIP) is also a technique of determining the porosity of coal [31][32][33], where liquid mercury is gradually injected into pores of coal with the increase of pressure by overcoming the surface tension. The higher injection pressure, the smaller pores can be penetrated by mercury.…”

Section: Introductionmentioning

confidence: 99%

Surface Properties and Pore Structure of Anthracite, Bituminous Coal and Lignite

et al. 2018

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Properties of coal surface and pore structure are important aspects to be investigated in coal preparation and utilization. In order to investigate the limits of different probe methods, a comprehensive approach was comparatively used to probe surface properties and pore structure of anthracite, bituminous coal and lignite. Surface morphology of the three coal samples was analyzed by scanning electron microscopy (SEM). Combining mercury intrusion porosimetry (MIP), physisorption method with carbon dioxide (CO 2) at 273 K and nitrogen (N 2) at 77 K was used to quantify a broad pore size distribution of coals, while FT-IR and water vapor sorption methods were used to study the coal surface properties. The results show that wedge-shaped pores develop with the increase of coal rank due to compression effect. The determined specific surface area (SSA) and pore volume of N 2 decrease with the increase of coal rank, while CO 2 SSA and pore volume are of a kind of U-shaped function of coal rank. MIP results indicate that that the pore size of 10-100 nm accounted for 70.7-97.5% of the total volume in the macropore range. Comparison of different methods indicates that micropores cannot be fully covered by the standard probes. CO 2 adsorption technique can only probe micropores in the range of 0.5 nm to 0.9 nm. Water vapor is not an effective probe to detect the micropores in coals, due to that the water clusters is mainly filled in mesopores and macropores. The results also show that both water vapor adsorption and FT-IR analysis can provide qualitative information of coal surface, rather than qualification of functional groups.

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“…The differential pressure was kept constant at 200 -500 mbar depending on the sample properties. The intrinsic sample permeability was derived from the apparent gas permeability, , determined for each pressure step using Darcy´s law (Liu et al 2017):…”

Section: Permeability Measurements and Pore Size Distributionmentioning

confidence: 99%

Simulating permeability reduction by clay mineral nanopores in a tight sandstone by combining μXCT and FIB-SEM imaging

Jacob¹,

Peltz²,

Hale³

et al. 2020

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Abstract. Computer microtomography (µXCT) represents a powerful tool for investigating the physical properties of porous rocks. While calculated porosities determined by this method typically match experimental measurements, computed permeabilities are often overestimated by more than one order of magnitude. This effect increases towards smaller pore sizes, as shown in this study, in which nanostructural features related to clay minerals reduce the permeability of tight reservoir sandstone samples. FIB-SEM tomography was applied to determine the permeability effects of illites at the nanometre scale and Navier-Stokes-equations were applied to calculate the permeability of these domains. With this data, microporous domains (porous voxels) were defined using microtomography images of a tight reservoir sample. The distribution of these domains could be extrapolated by calibration against size distributions measured in FIB-SEM images. For this, we assumed a mean permeability for the dominant clay mineral (illite) in the rock and assigned it to the microporous domains within the structure. The results prove the applicability of our novel approach by combining FIB-SEM with X-ray tomographic rock core scans to achieve a good correspondence between measured and simulated permeabilities. This methodology results in a more accurate representation of reservoir rock permeability in comparison to that estimated purely based on µXCT images.

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Determination of Klinkenberg Permeability Conditioned to Pore-Throat Structures in Tight Formations

Cited by 13 publications

References 22 publications

Experimental Determination of Gas Relative Permeability Considering Slippage Effect in a Tight Formation

Experimental Determination of Gas Relative Permeability Considering Slippage Effect in a Tight Formation

Surface Properties and Pore Structure of Anthracite, Bituminous Coal and Lignite

Simulating permeability reduction by clay mineral nanopores in a tight sandstone by combining μXCT and FIB-SEM imaging

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