流体力学格子法的外文文献及翻译资料

2.英文原文

SCIENCE CHINA

Earth Sciences

September 2013 Vol.56 No.9: 1519–1530

doi: 10.1007/s11430-013-4643-0

Lattice Boltzmann simulation of fluid flow through coal

reservoir’s fractal pore structure

JIN Yi1,2*, SONG HuiBo1,2, HU Bin1,2, ZHU YiBo1 & ZHENG JunLing1

1 School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454000, China;

2 Key Laboratory of Biogenic Traces & Sedimentary Minerals of Henan Province, Jiaozuo 454000, China

Received November 6, 2012; accepted March 28, 2013; published online June 27, 2013

The influences of fractal pore structure in coal reservoir on coalbed methane (CBM) migration were analyzed in detail by cou-pling theoretical models and numerical methods. Different types of fractals were generated based on the construction thought of the standard Menger Sponge to model the 3D nonlinear coal pore structures. Then a correlation model between the permea-bility of fractal porous medium and its pore-size-distribution characteristics was derived using the parallel and serial modes and verified by Lattice Boltzmann Method (LBM). Based on the coupled method, porosity (ϕ), fractal dimension of pore structure (D b), pore size range (r min, r max) and other parameters were systematically analyzed for their influences on the perme-ability (κ) of fractal porous medium. The results indicate that: ① the channels connected by pores with the maximum size (r max) dominate the permeability κ , approximating in the quadratic law; ② the greater the ratio of r max and r min is, the higher κ is; ③ the relationship between D b and κ follows a negative power law model, and breaks into two segments at the position where D b≌2.5. Based on the results above, a predicting model of fractal porous medium permeability was proposed, formu-

lated as κ =Cfr max n , where C and n (approximately equal to 2) are constants and f is an expression only containing parameters of fractal pore structure. In addition, the equivalence of the new proposed model for porous medium and the Kozeny-Carman model κ=Cr n was verified at D b=2.0.

fractal pore structure, porous media, lattice Boltzmann model, coalbed methane (CBM)

Citation:Jin Y, Song H B, Hu B, et al. Lattice Boltzmann simulation of fluid flow through coal reservoir’s fractal pore structure. Sci ence China: Earth Sci-ences, 2013, 56: 1519–1530, doi: 10.1007/s11430-013-4643-0

With the rapid development of industrial extraction and commercial exploitation of the CBM in China, more and more attention has been paid to the course of its genesis and migration law in coals.

As a dual-porosity medium, coal reservoir’s pore spaces which is a kind of matrix porous medium coupled with fractured network, dominates the storage and recoverability of CBM [1–5]. Due to various causes, the microstructures of pores in coal reservoir are always disordered and ex-tremely complicated. There is now considerable evidence at home and abroad showing that coal reservoir is a fractal

*Corresponding author (email: ) porous medium [1, 6–11].

Since the microstructures of the real porous media in coal are usually disordered and extremely complicated, this makes it very difficult to find the permeability of the media analytically and access the transport property of CBM ac-curately. Over the last several decades, the migration law of CBM in the fractal porous medium in coals has been inves-tigated both experimentally and theoretically by many au-thors [12–21]. But, experimental study is influenced heavily by many factors, such as experiment condition, scale, and testing environment. At the same time, the underlying con-tinuous media assumption makes the controlling mechanism of fluid flow hard to explore. As to the theoretical analyses

© Science China Press and Springer-Verlag Berlin Heidelberg 2013