珊瑚砂三维孔隙微观特性研究

Study on the microscopic characteristics of three-dimensional pores in coral sand

孔隙是多孔介质内渗流的发生场所,与介质渗透性存在必然的联系。珊瑚砂因其特殊的物质来源和形成过程,较陆源砂具有截然不同的孔隙特性。通过一系列微观研究手段,从本质上揭示了珊瑚砂特殊孔隙性质的原因。研究发现,从孔隙形状、孔喉尺寸和整体连通性3个角度描述孔隙性质较为合理。其中,孔隙形状用形状因子度量,孔喉尺寸包括孔隙半径和喉道半径,珊瑚砂多孔介质整体连通性利用配位数进行描述。而影响孔隙形状、孔喉尺寸和整体连通性的主导因素包括颗粒形状和颗粒表面粗糙度两方面。其中颗粒形状主要影响孔隙形状、喉道尺寸、孔喉尺寸离散性和介质内部连通性的均匀分布情况。颗粒表面粗糙度主要影响孔隙形状、孔隙形状离散性、孔隙尺寸和介质整体连通性。

The pore is the place where the seepage occurs in the porous medium,which is inevitably related to the permeability of the medium.Due to the special material source and formation process,coral sand has completely different pore characteristics compared with terrestrial sand.Through a series of microscopic studies,the reason for the special pore properties of coral sand in essence was revealed.It is found that it is reasonable to describe the properties of pores from the aspect of pore shape,pore throat size and global connectivity.Among them,pore shape is measured by the shape factor.Pore throat size includes pore radius and throat radius.Global connectivity in the porous media is described by coordination numbers.Particle shape and particle surface roughness are the main factors affecting pore shape,pore throat size and global connectivity.Particle shape mainly affects pore shape,throat size,pore throat size dispersion and the uniform distribution of connectivity in the medium.Particle surface roughness mainly affects pore shape,pore shape dispersion,pore size and global connectivity in the porous medium.