多孔介质中示踪剂微观可视化实验研究

为了更好地适应多孔介质示踪剂复杂渗流描述,针对微观孔道级别的示踪剂渗流机理和运移特征,应用孔隙结构仿真微观模型,设计完成了多孔介质示踪剂微观可视化实验,直接观察了多孔介质微观传质扩散过程和机理。实验结果表明：示踪剂运移微观上具有不同尺寸级别的绕流效应,且随着示踪剂在多孔介质中的推进,绕流尺寸明显增大;随着示踪剂向前推进,因混合作用明显,其质量浓度前缘梯度减小,且不再规则,同时横向宽度明显增大。示踪测试解释建模过程中,必须综合考虑示踪剂的混合作用、单个孔道的迂曲度、多个孔道的网络结构及小—大规模的绕流效应等情况。

Experimental study on microcosmic visualization of tracer in porous medium

In order to describe the complicated seepage flow process of tracer in porous medium,in view of the seepage flow mechanism and migration feature of the tracer with microcosmic porous channel level,the microscopic visualization experiment of tracer in porous medium is designed by using microscopic model of pore structure,and the micro porous media mass transfer diffusion process and mechanism are observed directly.The experiment results show that,for tracer migration,there is the flow around effect with different size on a microscopic level.Along with the advance of tracer in porous media,the flow around size is increased.With the tracer forward,the concentration gradient of concentration front is decreased because the mixing action is obvious,front is no longer regular,and horizontal width is increased obviously.During the modeling process of tracer test interpretation,the mixing effect,micro circuitous degree and network structure with multiple channels and the flow around effect between small scale and large scale must be comprehensively considered.