Title: Apparent permeability prediction of organic shale with generalized lattice Boltzmann model considering surface diffusion effect

Abstract

Gas flow in shale is associated with both organic matter (OM) and inorganic matter (IOM) which contain nano-pores ranging in size from a few to hundreds of nano-meters. In addition to the non-continuum effect which leads to an apparent permeability of gas higher than the intrinsic permeability, the surface diffusion of adsorbed gas in organic pores also can influence the apparent permeability through its own transport mechanism. In this study, a generalized lattice Boltzmann model (GLBM) is employed for gas flow through the reconstructed shale matrix consisting of OM and IOM. The Expectation–Maximization (EM) algorithm is used to assign the pore size distribution to each component, and the dusty gas model (DGM) and generalized Maxwell–Stefan model (GMS) are adopted to calculate the apparent permeability accounting for multiple transport mechanisms including viscous flow, Knudsen diffusion and surface diffusion. Effects of pore radius and pressure on permeability of both IOM and OM as well as effects of Langmuir parameters on OM are investigated. The effect of total organic content and distribution on the apparent permeability of the reconstructed shale matrix at different surface diffusivity is also studied. It is found that the influence of pore size and pressure on the apparent permeabilitymore » of organic matter is affected by the surface diffusion of adsorbed gas. Furthermore, surface diffusion plays a significant role in determining apparent permeability and the velocity distribution of shale matrix.« less

Authors:

Wang, Junjian ^[1]; Chen, Li ^[2]; Kang, Qinjun  ^[3];

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Rahman, Sheik S. ^[4]

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+ Show Author Affiliations

1. Univ. of New South Wales, Sydney, NSW (Australia); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Xi'an Jiaotong Univ., Shanxi (China); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
4. Univ. of New South Wales, Sydney, NSW (Australia)

Publication Date:

Thu May 12 00:00:00 EDT 2016

Research Org.:

Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Laboratory Directed Research and Development (LDRD) Program

OSTI Identifier:

1477708

Alternate Identifier(s):

OSTI ID: 1341461

Report Number(s):

LA-UR-17-27936
Journal ID: ISSN 0016-2361

Grant/Contract Number:  

AC52-06NA25396

Resource Type:

Accepted Manuscript

Journal Name:

Fuel

Additional Journal Information:

Journal Volume: 181; Journal Issue: C; Journal ID: ISSN 0016-2361

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

02 PETROLEUM; Earth Sciences; Energy Sciences; Shale gas; Lattice Boltzmann method; Surface diffusion