Lattice Boltzmann simulation of fluid flow through coal reservoir＇s fractal pore structure
The influences of fractal pore structure in coal reservoir on coalbed methane（CBM） migration were analyzed in detail by coupling 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 nonline...
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| Published in | 中国科学：地球科学英文版 no. 9; pp. 1519 - 1530 |
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| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
2013
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| Subjects | |
| Online Access | Get full text |
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| Summary: | The influences of fractal pore structure in coal reservoir on coalbed methane（CBM） migration were analyzed in detail by coupling 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 permeability 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（ф）,fractal dimension of pore structure（Db）,pore size range（rmin,rmax） and other parameters were systematically analyzed for their influences on the permeability（ф） of fractal porous medium.The results indicate that：① the channels connected by pores with the maximum size（rmax） dominate the permeability,approximating in the quadratic law;② the greater the ratio of r max and r min is,the higher is;③ the relationship between D b and follows a negative power law model,and breaks into two segments at the position where Db ≌2.5.Based on the results above,a predicting model of fractal porous medium permeability was proposed,formulated as k=cfrnmax,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 k=Crn was verified at Db =2.0. |
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| Bibliography: | Lattice Boltzmann simulation of fluid flow through coal reservoir＇s fractal pore structure The influences of fractal pore structure in coal reservoir on coalbed methane（CBM） migration were analyzed in detail by coupling 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 permeability 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（ф）,fractal dimension of pore structure（Db）,pore size range（rmin,rmax） and other parameters were systematically analyzed for their influences on the permeability（ф） of fractal porous medium.The results indicate that：① the channels connected by pores with the maximum size（rmax） dominate the permeability,approximating in the quadratic law;② the greater the ratio of r max and r min is,the higher is;③ the relationship between D b and follows a negative power law model,and breaks into two segments at the position where Db ≌2.5.Based on the results above,a predicting model of fractal porous medium permeability was proposed,formulated as k=cfrnmax,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 k=Crn was verified at Db =2.0. 11-5843/P |
| ISSN: | 1674-7313 1869-1897 |