基于REV尺度格子Boltzmann方法的页岩气流动数值模拟
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摘要
结合页岩扫描电镜图像,提出页岩气藏物理模型,采用表征单元体积(representative elementary volume,REV)尺度格子Boltzmann方法,考虑滑脱效应,模拟页岩气在页岩气藏中的流动.模拟结果表明,页岩气主要沿着天然裂缝窜进,但在有机质和无机质中也存在缓慢的流动,且有机质中的流速要略大于无机质中的流速.通过改变地层压力,研究地层压力对页岩气渗流特性的影响.研究结果表明,整个流场的速度和渗透率均随着地层压力的下降而增加.
During the seepage of the shale gas,its effect is due to the large Knudson number,which makes the gas molecules slip from the solid surface.Based on the REV(representative elementary volume) scale lattice Boltzmann method,the flow of the shale gas is simulated with consideration of the slippage effect.With the scanning electron microscope image,a physical model with organic rock,nonorganic rock and natural fractures is taken,and then the shale gas flow in the model is simulated.The simulated results indicate that the shale gas mainly flows in the natural fractures.However,the shale gas also flows slowly in the organic and nonorganic rocks,and the velocity in the organic rocks is larger than that in the nonorganic rocks.The influence of the reservoir pressure on the shale gas seepage is also studied by varying the reservoir pressure.It is indicated that with the decrease of the reservoir pressure,the Knudson number increases and the slippage effect intensifies,thus the velocity and the permeability of the whole fluid field increase.
During the seepage of the shale gas,its effect is due to the large Knudson number,which makes the gas molecules slip from the solid surface.Based on the REV(representative elementary volume) scale lattice Boltzmann method,the flow of the shale gas is simulated with consideration of the slippage effect.With the scanning electron microscope image,a physical model with organic rock,nonorganic rock and natural fractures is taken,and then the shale gas flow in the model is simulated.The simulated results indicate that the shale gas mainly flows in the natural fractures.However,the shale gas also flows slowly in the organic and nonorganic rocks,and the velocity in the organic rocks is larger than that in the nonorganic rocks.The influence of the reservoir pressure on the shale gas seepage is also studied by varying the reservoir pressure.It is indicated that with the decrease of the reservoir pressure,the Knudson number increases and the slippage effect intensifies,thus the velocity and the permeability of the whole fluid field increase.
引文
1金衍,程万,陈勉.页岩气储层压裂数值模拟技术研究进展.力学与实践,2016,38(1):1-9
2 朱维耀,邓佳,杨宝华等.页岩气致密储层渗流模型及压裂直井产能分析.力学与实践,2014,36(2):157-160
3 郭为,胡志明,左罗等.页岩基质解吸–扩散–渗流耦合实验及数学模型.力学学报,2015,47(6):916-922
4 朱光普,姚军,樊冬艳等.页岩气藏压裂水平井试井分析.力学学报,2015,47(6):945-954
5 Wang JJ,Chen L,Kang QJ,et al.Apparent permeability prediction of organic shale with generalized lattice Boltzmann model considering surface diffusion effect.Fuel,2016,181:478-490
6 张潇丹,雍玉梅,李文军等.REV尺度多孔介质格子Boltzmann方法的数学模型及应用的研究进展.化工进展,2016,35(6):1698-1712
7 Guo ZL,Zhao TS.Lattice Boltzmann model for incompressible flows through porous media.Phys Rev E,2002,66:036304
8 张磊,姚军,孙海等.基于数字岩心技术的气体解析/扩散格子Boltzmann模拟.石油学报,2015,36(3):161-365
9 Chen L,Fang WZ,Kang QJ,et al.Generalized lattice Boltzmann model for flow through tight porous media with Klinkenberg’s effect.Phys Rev E,2015,91:033004
10 Nithiarasu P,Seetharamu KN,Sundararajan T.Natural convective heat transfer in a fluid saturated variable porosity medium.International Journal of Heat and Mass Transfer,1997,40(16):3955-3967
11 Gao JF,Xing HL,Tian ZW,et al.Lattice Boltzmann modeling and evaluation of fluid flow in heterogeneous porous media involving multiple matrix constituents.Computers&Geosciences,2014,62:198-207
12 Carman PC.Fluid flow through granular beds.Trans Inst Chem Eng,1937,15:150-167
13 Beskok A,Karniadakis G.Report a model for flows in channels,pipes,and ducts at micro and nano scales.Microscale Therm Emg,1999,3(1):43-77
14 Civan F.Effective correlation of apparent gas permeability in tight porous media.Transp Porous Med,2010,82:375-384
15 Qian YH,d’Humieres D,Lallemand P.Lattice BGK model for Navier--Stokes equation.Europhysics Letters,1992,17(6):479-484
16 申林方,王志良,李邵军.基于格子博尔兹曼方法表征体元尺度土体细观渗流场的数值模拟.岩土力学,2015,36(2):689-694
2 朱维耀,邓佳,杨宝华等.页岩气致密储层渗流模型及压裂直井产能分析.力学与实践,2014,36(2):157-160
3 郭为,胡志明,左罗等.页岩基质解吸–扩散–渗流耦合实验及数学模型.力学学报,2015,47(6):916-922
4 朱光普,姚军,樊冬艳等.页岩气藏压裂水平井试井分析.力学学报,2015,47(6):945-954
5 Wang JJ,Chen L,Kang QJ,et al.Apparent permeability prediction of organic shale with generalized lattice Boltzmann model considering surface diffusion effect.Fuel,2016,181:478-490
6 张潇丹,雍玉梅,李文军等.REV尺度多孔介质格子Boltzmann方法的数学模型及应用的研究进展.化工进展,2016,35(6):1698-1712
7 Guo ZL,Zhao TS.Lattice Boltzmann model for incompressible flows through porous media.Phys Rev E,2002,66:036304
8 张磊,姚军,孙海等.基于数字岩心技术的气体解析/扩散格子Boltzmann模拟.石油学报,2015,36(3):161-365
9 Chen L,Fang WZ,Kang QJ,et al.Generalized lattice Boltzmann model for flow through tight porous media with Klinkenberg’s effect.Phys Rev E,2015,91:033004
10 Nithiarasu P,Seetharamu KN,Sundararajan T.Natural convective heat transfer in a fluid saturated variable porosity medium.International Journal of Heat and Mass Transfer,1997,40(16):3955-3967
11 Gao JF,Xing HL,Tian ZW,et al.Lattice Boltzmann modeling and evaluation of fluid flow in heterogeneous porous media involving multiple matrix constituents.Computers&Geosciences,2014,62:198-207
12 Carman PC.Fluid flow through granular beds.Trans Inst Chem Eng,1937,15:150-167
13 Beskok A,Karniadakis G.Report a model for flows in channels,pipes,and ducts at micro and nano scales.Microscale Therm Emg,1999,3(1):43-77
14 Civan F.Effective correlation of apparent gas permeability in tight porous media.Transp Porous Med,2010,82:375-384
15 Qian YH,d’Humieres D,Lallemand P.Lattice BGK model for Navier--Stokes equation.Europhysics Letters,1992,17(6):479-484
16 申林方,王志良,李邵军.基于格子博尔兹曼方法表征体元尺度土体细观渗流场的数值模拟.岩土力学,2015,36(2):689-694