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

Journal Article · Thu May 12 00:00:00 EDT 2016 · Fuel

DOI:https://doi.org/10.1016/j.fuel.2016.05.032· OSTI ID:1477708

Wang, Junjian ^[1]; Chen, Li ^[2]; Kang, Qinjun ^[3]; Rahman, Sheik S. ^[4]

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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)

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 permeability 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.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: LDRD; USDOE
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1477708
• Alternate ID(s): OSTI ID: 1341461
• Report Number(s): LA-UR--17-27936
• Journal Information: Fuel, Journal Name: Fuel Journal Issue: C Vol. 181; ISSN 0016-2361
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

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