Journal ArticleDOI
Dynamic gas slippage: a unique dual-mechanism approach to the flow of gas in tight formations.
TLDR
In this paper, a mathematical formulation for the flow of gas in very tight porous media and including a dual-mechanism transport of gas is developed, where gas is assumed to be traveling under the influence of a concentration field and a pressure field.Abstract:
A mathematical formulation, applicable to both numerical simulation and transient well analysis that describes the flow of gas in very tight porous media and includes a dual-mechanism transport of gas is developed. Gas is assumed to be traveling under the influence of a concentration field and a pressure field. Transport through the concentration field is a Knudsen flow process and is modeled with Fick's law of diffusion. Transport through the pressure field is a laminar process and is modeled with Darcy's law (inertial/turbulent effects are ignored). The combination of these two flow mechanisms rigorously yields a composition-, pressure-, and saturation-dependent slippage factor. The pressure dependence arises from treating the gas as a real gas. The derived dynamic slippage is most applicable in reservoirs with permeabilities less than or equal to0.01 md. The results indicate that in reservoirs of this type, differences between recoveries after 10 years of production with the dynamic-slip and constant-slip approaches were as great as 10%, depending on the initial gas saturation. If an economic production rate is considered, differences as great as 30% can be expected.read more
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Sequestration of Carbon Dioxide in Coal with Enhanced Coalbed Methane RecoveryA Review
Curt M. White,Duane H. Smith,Kenneth L. Jones,Angela L. Goodman,Sinisha A. Jikich,Robert B. LaCount,Stephen B. DuBose,Ekrem Ozdemir,Badie I. Morsi,Karl T. Schroeder +9 more
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Journal ArticleDOI
Knudsen’s Permeability Correction for Tight Porous Media
Ali S. Ziarani,Roberto Aguilera +1 more
TL;DR: In this article, a higher-order correlation for gas flow called Knudsen's permeability is studied, which is more accurate than Klinkenberg's model especially for extremely tight porous media with transition and free molecular flow regimes.
Journal ArticleDOI
Real gas transport through nanopores of varying cross-section type and shape in shale gas reservoirs
TL;DR: In this paper, a model for real gas transport in nanopores of shale gas reservoirs (SGRs) was proposed on the basis of the weighted superposition of slip flow and Knudsen diffusion, where the ratios of the intermolecular collisions and the molecule-nanopore wall collisions to the total collisions are the weighted factors of slip flows and diffusion, respectively.