The saturation and immersion expansions and the heat of wetting

Bangham, D. H.; Razouk, R. I.

doi:10.1098/rspa.1938.0112

Cited by 54 publications

(16 citation statements)

References 2 publications

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“…McBain and Ferguson (1927) were the first to report swelling of sandstone, limestone, and cement caused by increase of air humidity, although they did not conduct any measurements of strain. Throughout next several decades, studies of adsorption-induced deformation were focused on charcoal (Bangham & Fakhoury, 1928;Bangham & Razouk, 1938;Briggs & Sinha, 1934;Meehan, 1927), porous glasses (e.g., Amberg & McIntosh, 1952), and silica (e.g., Reichenauer & Scherer, 2000, 2001. The order of observed deformation in carbons and glasses was about 10 À3 , while measurements on high-porous silica aerogel showed huge strain of 30%.…”

Section: Introductionmentioning

confidence: 99%

Sorption‐Induced Deformation and Elastic Weakening of Bentheim Sandstone

et al. 2018

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A number of studies show that adsorption of small amount of water causes significant reduction of elastic moduli and increase of elastic wave attenuation in sandstones. This effect is of practical importance for near‐surface seismic studies and for applications of conventional rock physics theories, which require measurements of elastic properties of dry rock. Additionally, adsorption of water causes deformation of porous materials and rocks, which can be explained by the concept of varying surface stress, or change in the pressure of fluid adsorbed in pores. In this work we suggest that the adsorption‐induced elastic weakening of sandstones is caused by changing fluid pressure in compliant pores on grain contacts. In order to validate this concept, we conduct simultaneous measurements of the elastic moduli and deformation of the Bentheim sandstone with adsorption and desorption of water and observe ~20% change in the bulk and shear moduli accompanied with the strain of the order of 10−4. Then, we estimate that the fluid pressure change should be of the order of several megapascals to cause such deformation. Comparison of the measured variations in the elastic moduli related to the estimated change in the fluid pressure with the stress dependency of the bulk and shear moduli in Bentheim sandstone shows a broad agreement of the two sets of measurements. A reasonable magnitude of the estimated fluid pressure change is consistent with the suggested hypothesis.

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Section: Introductionmentioning

confidence: 99%

Sorption‐Induced Deformation and Elastic Weakening of Bentheim Sandstone

et al. 2018

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“…18 Sorption of water and water vapor can stress the physical structure of BC because of exothermic graphitic sheet swelling. 19 These mechanisms result in swelling and expansion of the physical biochar structure, which improves the opportunity for further physical weathering. 20 Furthermore, fresh exposures of new biochar surfaces and fissures could accelerate microbial mineralization, 21 abiotic reactions, 22 or surface sorption phenomena.…”

Section: ■ Introductionmentioning

confidence: 99%

“…5 Others have observed that once biochar is exposed to soils, soil particles can fill exposed cavities and fissures 16 ( Figure S4 of the Supporting Information). These sealing processes could be accelerated by exothermic water sorption onto BC surfaces 19 and accelerate desiccation drying. It is conceivable that the physical accumulation of colloidal, dissolved, and particulate material, including soluble inorganic salts and/or aluminosilicates, would rapidly infill fractures and pores 43 ( Figure S4 of the Supporting Information).…”

mentioning

confidence: 99%

Physical Disintegration of Biochar: An Overlooked Process

Spokas

Novak

Masiello

et al. 2014

Environ. Sci. Technol. Lett.

287

154

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Data collected from both artificially and field (naturally) weathered biochar suggest that a potentially significant pathway of biochar disappearance is through physical breakdown of the biochar structure. Via scanning electron microscopy, we characterized this physical weathering that increased the number of structural fractures and yielded higher numbers of liberated biochar fragments. This was hypothesized to be due to the graphitic sheet expansion accompanying water sorption coupled with comminution. These fragments can be on the microscale and the nanoscale but are still carbon-rich particles with no detectable alteration in the oxygen:carbon ratio from that of the original biochar. However, these particles are now easily dissolved and could be moved by infiltration. There is a need to understand how to produce biochars that are resistant to physical degradation to maximize long-term biochar C sequestration potential within soil systems.

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“…where ρ is the shale density in 3 kg/m , R is a molar gas constant ( 8.314 J/(mol K) ⋅ ), T is the reservoir temperature in K , p is the reservoir pressure in MPa , E is the Young's modulus in GPa , V is the gas adsorption amount in 3 cm /g , and L P is the Langmuir pressure in MPa . Seidle [57,58] presented a model describing the effect of matrix shrinkage deformation on the reservoir porosity. Therefore, the relationship between the change of porosity φ and matrix strain ε Δ can be proposed as…”

Section: Permeability Dynamic Changes Under Matrix Shrinkage and Strementioning

confidence: 99%

Gas Multiple Flow Mechanisms and Apparent Permeability Evaluation in Shale Reservoirs

Feng

Zhao

et al. 2019

Sustainability

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Gas flow mechanisms and apparent permeability are important factors for predicating gas production in shale reservoirs. In this study, an apparent permeability model for describing gas multiple flow mechanisms in nanopores is developed and incorporated into the COMSOL solver. In addition, a dynamic permeability equation is proposed to analyze the effects of matrix shrinkage and stress sensitivity. The results indicate that pore size enlargement increases gas seepage capacity of a shale reservoir. Compared to conventional reservoirs, the ratio of apparent permeability to Darcy permeability is higher by about 1–2 orders of magnitude in small pores (1–10 nm) and at low pressures (0–5 MPa) due to multiple flow mechanisms. Flow mechanisms mainly include surface diffusion, Knudsen diffusion, and skip flow. Its weight is affected by pore size, reservoir pressure, and temperature, especially pore size ranging from 1 nm to 5 nm and reservoir pressures below 5 MPa. The combined effects of matrix shrinkage and stress sensitivity induce nanopores closure. Therefore, permeability declines about 1 order of magnitude compare to initial apparent permeability. The results also show that permeability should be adjusted during gas production to ensure a better accuracy.

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The saturation and immersion expansions and the heat of wetting

Cited by 54 publications

References 2 publications

Sorption‐Induced Deformation and Elastic Weakening of Bentheim Sandstone

Sorption‐Induced Deformation and Elastic Weakening of Bentheim Sandstone

Physical Disintegration of Biochar: An Overlooked Process

Gas Multiple Flow Mechanisms and Apparent Permeability Evaluation in Shale Reservoirs

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