用Lattice Boltzmann压力模型模拟纳米增注实验的流动参数

Flow simulation of core displacement experiments for enhancing water injection technology with pressure-based Lattice Boltzman model

经岩心流动实验证实,岩心经纳米颗粒吸附法处理后,水流速度加快,岩心的水相渗透率有了大幅提高,平均达到82%。采用Forchheimer-Darcy模型描述岩心微孔道内的流体流动特征,建立了多孔介质表征体单元(REV)尺度上的不可压Lattice Boltzmann(LB)压力模型,编制了修正反弹格式的LB模拟程序,模拟了多块岩心的渗流效果,计算了纳米颗粒吸附法处理前、后的相关流动参数。数值模拟结果与实验结果吻合较好,说明LB压力模型适合模拟多孔介质的流动,在纳米增注渗流机制研究方面将有很好的应用前景。

The results of the core displacement experiments show that,after treatment with Hydrophobic Nanoparticles(HNPs),the fluid velocity was increased and the water-phase effective permeability(WPEP) was increased about 82 percent averagely.The characteristics of water flow through the microchannels in cores are described as Forchheimer-Darcy model.A incompressible Lattice Boltzmannn(LB) method,which is at the representative elementary volume(REV) scale of porous media,was established also.A LB simulation program including modified bounce-back scheme at upper and lower boundaries was written to simulate the flow behavior in cores and the WPEP before and after treatment with HNPs.A good agreement of numerical prediction and the data of experiments shows that the pressure-based LB method is suitable for studying the flow in porous media,and has very good application prospect on the mechanism research of enhancing water injection with the HNPs.