Understanding capture of non-Brownian particles in porous media with network model

摘要

Particles can invade porous media such as reservoir rocks and deep-bed filters, causing severe damage to their permeabilities. The mechanisms of permeability decline are attributed to surface deposition, bridging and size exclusion of particles in porous media. Traditional models are empirical correlations heavily dependent on filtration data. In this paper, a 2D square network model incorporating the damaging mechanisms is used to study the capture of non-Brownian particles in porous media and the resultant permeability damage. The model employs certain assumptions to imitate the characteristics of real porous media. The proposed procedure applies force analysis to obtain particle invasion depth, and determines damaging mechanisms by pore size to particle size ratio. The method is validated with test data and reasonably good results are obtained. The new model provides more insights into the capture process and does not rely on core flooding data.