Journal ArticleDOI
An Experimental Study on the Slippage Effect of Gas Flow in a Compact Rock
TLDR
In this paper, the authors measured the porosity of two granitic gneiss specimens under different pore and confining pressures and found that when the confining pressure is high and the pore pressure is low, the flows are slip flow and transitional flow and traditional fluid dynamics N-S equations are not applicable and Knudsen diffusion equations should be used.Abstract:
Gas flow in small pore throats in compact rocks is usually affected by the gas slippage effect due to the dense structure and low porosity of the rocks. In this study, permeability and porosity of two granitic gneiss specimens under different pore and confining pressures are measured. Petrographic studies are also performed using X-ray diffraction, optical microscopy, and scanning electron microscopy coupled with an energy-dispersive spectrometer. Test data indicate that the gas flow in the compact rock does not follow Darcy’s law due to the effect of gas slippage, and the measured permeability needs to be corrected by the gas slippage effect. The test results show that the gas slippage effect increases subsequently when the pore pressure is low, which leads to the measured permeability higher than the absolute permeability. The influence of confining pressure on the impact rate of the slippage effect appears to approach an upper limit symptomatically. It is found that a power law describes well the relationship between the absolute permeability and the effective porosity. A correlation of the slippage factor and the absolute permeability is provided. When the confining pressure is high and the pore pressure is low, the flows are slip flow and transitional flow and traditional fluid dynamics N–S equations are not applicable and Knudsen’s diffusion equations should be used.read more
Citations
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Journal ArticleDOI
Gas Permeability and Porosity Evolution of a Porous Sandstone Under Repeated Loading and Unloading Conditions
TL;DR: In this paper, a power law is suggested to describe the relationship between the stress-dependent porosity and permeability of the sandstone under both loading and unloading conditions within the stress range used in the experiment.
Journal ArticleDOI
KG²B, a collaborative benchmarking exercise for estimating the permeability of the Grimsel granodiorite – Part 1: measurements, pressure dependence and pore-fluid effects
Christian David,J. Wassermann,Florian Amann,David A. Lockner,Ernest H. Rutter,Tiziana Vanorio,A. Amann Hildenbrand,J. Billiotte,Thierry Reuschlé,Didier Lasseux,Jérôme Fortin,R. Lenormand,A.P.S. Selvadurai,Philip G. Meredith,John Browning,Thomas M. Mitchell,Didier Loggia,Franck Nono,Joel Sarout,Lionel Esteban,Catherine A. Davy,L. Louis,G. Boitnott,Claudio Madonna,E. Jahns,Fleury. M.,G. Berthe,Pierre Delage,Philipp Braun,David Grégoire,Laurent Perrier,P. J. Polito,Yves Jannot,Alain Sommier,B.M. Krooss,Reinhard Fink,Qinhong Hu,Jop Klaver,Anthony C. Clark +38 more
TL;DR: In this paper, a collaborative benchmarking exercise involving 24 laboratories was organized for measuring the permeability of a single low permeability material, the Grimsel granodiorite, at a common effective confining pressure (5 MPa).
Journal ArticleDOI
Relative Permeability of Gas for Unconventional Reservoirs
TL;DR: In this article, a universal relative permeability model for coal, tight sandstone and shale gas is proposed, where the effects of water saturation and mean pore pressure on gas slippage permeability are taken into account.
Journal ArticleDOI
Laboratory investigations of inert gas flow behaviors in compact sandstone
TL;DR: In this article, both hydrostatic and triaxial compression tests were conducted on compact sandstone using an inert gas, namely argon, to study the difference between the gas permeability and water permeability evolutions during the complete stress-strain process.
Journal ArticleDOI
KG²B, a collaborative benchmarking exercise for estimating the permeability of the Grimsel granodiorite—Part 2: modelling, microstructures and complementary data
Christian David,J. Wassermann,Florian Amann,Jop Klaver,Catherine A. Davy,Joel Sarout,Lionel Esteban,Ernest H. Rutter,Qinhong Hu,L. Louis,Pierre Delage,David A. Lockner,A.P.S. Selvadurai,Tiziana Vanorio,A. Amann Hildenbrand,Philip G. Meredith,John Browning,Thomas M. Mitchell,Claudio Madonna,J. Billiotte,Thierry Reuschlé,Didier Lasseux,Jérôme Fortin,R. Lenormand,Didier Loggia,Franck Nono,G. Boitnott,E. Jahns,Fleury. M.,G. Berthe,Philipp Braun,David Grégoire,Laurent Perrier,P. J. Polito,Yves Jannot,Alain Sommier,B.M. Krooss,Reinhard Fink,Anthony C. Clark +38 more
TL;DR: In this article, a benchmarking exercise involving 24 laboratories was organized for measuring and modelling the permeability of a single low-permeability material, the Grimsel granodiorite, and the objectives of the benchmark were: (i) to compare the results for a given method, (ii) to contrast the results between different methods, (iii) to analyse the accuracy of each method, and (iv) to study the influence of experimental conditions (especially the nature of pore fluid), (v) to discuss the relevance of indirect methods and models and finally (vi
References
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Book
Molecular Gas Dynamics and the Direct Simulation of Gas Flows
TL;DR: The direct simulation Monte Carlo (or DSMC) method has, in recent years, become widely used in engineering and scientific studies of gas flows that involve low densities or very small physical dimensions as mentioned in this paper.
Journal ArticleDOI
Permeability of granite under high pressure
TL;DR: In this article, the authors measured the porosity of Westerly granite as a function of effective pressure to 4 kb and found that porosity is correlated with the electrical resistivity of the granite.
Journal ArticleDOI
On Stresses in Rarified Gases arising from Inequalities of Temperature
TL;DR: In this paper, it was shown that the difference between the maximum and the minimum pressure at a point may be of considerable magnitude when the density of the gas is small enough, and when the inequalities of temperature are produced by small solid bodies at a higher or lower temperature than the vessel containing the gas.