A novel approach for modeling permeability decline due to mineral scaling: Coupling geochemistry and deep bed filtration theory

Abstract

Mixing incompatible brines is one of the leading causes of mineral precipitation in porous media. Deposition of the precipitated minerals in pore spaces leads to the porosity and permeability reduction. This study, in the first step, proposes a novel coupled approach for modeling mineral precipitation and deposition in porous media based on geochemistry and deep bed filtration theory. In the proposed approach, minerals precipitate as suspended particles modeled by PHREEQC geochemical package, and deposition of the precipitated minerals is modeled through the deep bed filtration theory. During the second step, results of the proposed approach are verified using the reported experimental data, which show the proposed approach is applicable and accurate with a high degree of confidence. In the third step, the impact of mineral scaling on deposition pattern and permeability decline is studied with respect to the porosity heterogeneity, the existence of fracture, and heterogeneity in the matching parameters of the model. The results of this study show that the porosity heterogeneity influences not only the deposition pattern of the precipitated minerals but also the amount of permeability decline. This paper demonstrates that deep invasion of the precipitated minerals through the porosity heterogeneity and fracture intensifies the permeability decline. It is also observed that heterogeneities in the modeling parameters (formation damage and filtration coefficients) do not affect the permeability decline of the porous media.