scholarly journals Matrix gas flow through ‘impermeable’ rocks – shales and tight sandstone

2021 ◽  
Author(s):  
Ernest Henry Rutter ◽  
Julian Mecklenburgh ◽  
Yusuf Bashir
Keyword(s):  
Gas Flow ◽  
Total Porosity ◽  
Small Range ◽  
Pressure Sensitivity ◽  
Effective Pressure ◽  
Tight Sandstone ◽  
Flow Through ◽  
Low Pressures ◽  
And Storage ◽  
Typical Range

Abstract. The effective pressure sensitivity of gas flow through two shales (Bowland and Haynesville shales) and a tight gas sandstone (Pennant sandstone) was measured over the typical range of reservoir pressure conditions. These are low permeability rocks such as can be exploited as caprocks above reservoirs that might be developed to store compressed air, methane, hydrogen or to bury waste carbon dioxide, all of which may become important components of the forthcoming major changes in methods of energy generation and storage. Knowledge of the petrophysical properties of such tight rocks will be of great importance in such developments. All three rocks display only a small range in log10 permeability at low pressures, but these decrease at dramatically different rates with increasing effective pressure, and the rate of decrease itself decreases with pressure, as the rocks stiffen. The pressure sensitivity of the bulk moduli of each of these rocks was also measured, and used to formulate a description of the permeability decrease in terms of the progressive closure of narrow, crack-like pores with increasing pressure. In the case of the shales in particular, only a very small proportion of the total porosity takes part in the flow of gases, particularly along the bedding layering.

Study of the Influence of the Add оf Micropores on Filtering Characteristics of High Porous Structures

2020 ◽  
Vol 24 (9) ◽  
pp. 39-43
Author(s):  
O.V. Soloveva ◽  
S.A. Solovev ◽  
R.R. Yafizov
Keyword(s):  
Quality Factor ◽  
Particle Deposition ◽  
Gas Flow ◽  
Numerical Study ◽  
Total Porosity ◽  
Deposition Efficiency ◽  
Open Cell Foam ◽  
Flow Through ◽  
Highly Porous ◽  
Highly Porous Material

In this work we carried out a numerical study of the gas flow through an open cell foam material with solid-state partitions and partitions containing micropores. The effect of a geometry change by adding micropores on the pressure drop, particle deposition efficiency, and filter quality factor is estimated. The results showed that the addition of micropores positively affects the filtering and hydrodynamic properties of the highly porous material for the same macroporosity of the medium, and for the case of total porosity of the medium, the material with micropores allows one to obtain an increased value of the deposition efficiency and filter quality factor for small particles.

Effects of Essential Oil Treatment, Gas Atmosphere, and Storage Temperature on Listeria monocytogenes in a Model Vegetable System

2009 ◽  
Vol 72 (6) ◽  
pp. 1209-1215 ◽  
Author(s):  
JOHANN SCOLLARD ◽  
GILLIAN A. FRANCIS ◽  
DAVID O'BEIRNE
Keyword(s):  
Pathogenic Bacteria ◽  
Gas Flow ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Plant Essential Oils ◽  
Gas Atmosphere ◽  
Disk Diffusion Assay ◽  
Storage Atmosphere ◽  
Flow Through ◽  
And Storage

Natural antimicrobials such as plant essential oils (EOs) may be useful for controlling pathogenic bacteria on fresh-cut vegetables. The antilisterial properties of EOs (thyme, oregano, and rosemary), in combination with different storage atmospheres (air, 5% CO2–2% O2–93% N2, and 20% CO2–1% O2–79% N2) and temperatures (4 and 8°C), were examined using a gas flow-through system combined with a vegetable agar model. The antimicrobial effects of the EOs varied depending on the oil, the Listeria strain and species, the method of application, and the storage conditions tested. Using the disk diffusion assay, the antilisterial effectiveness of the oils was in the following order: thyme EO > oregano EO > rosemary EO. Volatiles released from the EOs resulted in very small antilisterial effects, indicating that the oils needed to be in direct contact with cultures in order to be effective. There were strain and species effects, with L. innocua NCTC 11288 exhibiting the strongest resistance to EOs, and L. monocytogenes NCTC 7973 being the most sensitive strain. In addition, the effectiveness of the EOs was influenced by storage atmosphere and temperature. Use of EOs in combination with a gas atmosphere of 20% CO2–1% O2–79% N2 had the greatest antilisterial effect, suggesting that high CO2 atmospheres enhanced the antilisterial properties of EOs. Lowering the storage temperature from 8 to 4°C improved the antilisterial activity of thyme oil. It is concluded that thyme and oregano EOs display strong inhibitory effects against Listeria and that increasing CO2 levels and lowering storage temperatures further enhance these antilisterial effects.

Microstructure of Cement Paste and Mass Transfer of Gas through Concrete

1986 ◽  
Vol 85 ◽  
Author(s):  
R. H. Mills
Keyword(s):  
Mass Transfer ◽  
Surface Area ◽  
Gas Flow ◽  
Pore Radius ◽  
Total Porosity ◽  
Bet Surface Area ◽  
Pore System ◽  
Specific Permeability ◽  
Flow Through ◽  
Image Position

ABSTRACTGas flow through concrete may be modelled by a relationship:where D* is the specific permeability, N* is the number of unit pores per m2, and α, β and γ are experimental constants.A unit pore is defined by the hydraulic mean radius a* equal to the total porosity divided by the BET surface area. The value of a* is estimated from porosity and hydration parameters to lie between 1.6 and 2.8 nm for water-cement ratios from 0.42 to 0.77 and initial porosities from 0.292 to 0.150. Estimation of pore radius a from gas flow yielded values of a/a* varying from 72 to 6. There appears to be fair correlation between N* and D*, but it appears that flow passes through microcracks rather than the natural pore system.

INVESTIGATION OF THE TIME OF GAS FLOW THROUGH A HOLE IN LONG PIPELINES UNDER HIGH PRESSURE

2020 ◽  
Vol 58 (1) ◽  
pp. 30-43
Author(s):  
N.D. Yakimov ◽  
◽  
A.I. Khafizova ◽  
N.D. Chichirova ◽  
O.S. Dmitrieva ◽  
...  
Keyword(s):  
High Pressure ◽  
Gas Flow ◽  
Flow Through

Free area for gas flow through sieve plates with a bubbled bed

1975 ◽  
Vol 40 (11) ◽  
pp. 3315-3318 ◽  
Author(s):  
M. Rylek ◽  
F. Kaštánek ◽  
L. Nývlt ◽  
J. Kratochvíl
Keyword(s):  
Gas Flow ◽  
Flow Through ◽  
Sieve Plates ◽  
Free Area

scholarly journals A Study on Liquid Leak Rates in Packing Seals

2021 ◽  
Vol 11 (4) ◽  
pp. 1936
Author(s):  
Abdel-Hakim Bouzid
Keyword(s):  
Environmental Protection ◽  
Liquid Flow ◽  
Environmental Protection Agency ◽  
Gas Flow ◽  
Outer Boundary ◽  
Health And Safety ◽  
Toxic Substances ◽  
Packing Materials ◽  
Thickness Change ◽  
Flow Through

The accurate prediction of liquid leak rates in packing seals is an important step in the design of stuffing boxes, in order to comply with environmental protection laws and health and safety regulations regarding the release of toxic substances or fugitive emissions, such as those implemented by the Environmental Protection Agency (EPA) and the Technische Anleitung zur Reinhaltung der Luft (TA Luft). Most recent studies conducted on seals have concentrated on the prediction of gas flow, with little to no effort put toward predicting liquid flow. As a result, there is a need to simulate liquid flow through sealing materials in order to predict leakage into the outer boundary. Modelling of liquid flow through porous packing materials was addressed in this work. Characterization of their porous structure was determined to be a key parameter in the prediction of liquid flow through packing materials; the relationship between gland stress and leak rate was also acknowledged. The proposed methodology started by conducting experimental leak measurements with helium gas to characterize the number and size of capillaries. Liquid leak tests with water and kerosene were then conducted in order to validate the predictions. This study showed that liquid leak rates in packed stuffing boxes could be predicted with reasonable accuracy for low gland stresses. It was found that internal pressure and compression stress had an effect on leakage, as did the thickness change and the type of fluid. The measured leak rates were in the range of 0.062 to 5.7 mg/s for gases and 0.0013 and 5.5 mg/s for liquids.

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