Kinetics And Equilibrium Of Nanogel Adsorption And Desorption On Sandstone
Polymer nanogels, elastic nanospheres with 3D network structure, have been recognized as promising materials to enhance oil recovery because they are designed to transport in deep of reservoirs for in-depth fluid diversion. Although conventional hard nanoparticles have been intensively investigated, the dynamic adsorption and desorption of elastic polymer nanospheres in porous media are still unclear, causing the uncertainty of applying them in the deep of reservoirs. In this work, we conducted circulation flowing experiments and post water flooding experiments to investigate the dynamic adsorption and desorption of nanogel in sandstones. Through UV–vis spectrophotometer, we found that nanogel exhibited rapid adsorption and desorption at the initial stages, but they have a long tail to reach equilibrium, in which the adsorption density distributed from 0.083 to 0.435 mg/g. The adsorption of nanogel increased with their concentration and core permeability, as well as salt concentration. However, salinity played a more important role during the desorption process due to the strong interaction between nanogel and sandstones. We also calculated the adsorption layer thickness, which ranges from 0.67 to 2.14, the results suggested that most of nanogel adsorption are multilayered processes. And the adsorption kinetics were fit by empirical equations, including pseudo-first order and pseudo-second order. The fitting comparison showed that the pseudo-first-order model is better suited for extreme low or high salinity (0.05% and 10% NaCl), while the pseudo-second-order model is preferred for moderate salinity (1% NaCl). These findings provide valuable insights for the effective placement of nanogel in oil recovery processes.
Q. He et al., "Kinetics And Equilibrium Of Nanogel Adsorption And Desorption On Sandstone," Journal of Molecular Liquids, vol. 387, article no. 122695, Elsevier, Oct 2023.
The definitive version is available at https://doi.org/10.1016/j.molliq.2023.122695
Geosciences and Geological and Petroleum Engineering
Chemical and Biochemical Engineering
Keywords and Phrases
Adsorption; Desorption; Nanogel; Pseudo kinetics
International Standard Serial Number (ISSN)
Article - Journal
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01 Oct 2023