Adsorption study of non-ionic ethoxylated nonylphenol surfactant for sandstone reservoirs: Batch and continuous flow systems

The use of surfactants in Enhanced Oil Recovery (EOR) projects has been extensively studied. The process of adsorption of these substances in the reservoir rocks is strictly important, since it provides a change in their wettability, allowing an increase in the oil recovery factor. However, the understanding of how the adsorption of surfactants occurs and the main phenomena involved in this process is still widely discussed. Thus, the objective of this work is to investigate and elucidate the adsorption behavior of surfactants of the Nonylphenol ethoxylated family (10EO, 40EO and 100EO) in sandstone rocks. It was possible to verify that the higher the degree of ethoxylation of the surfactant solutions used, the lower the adsorption capacity. The batch adsorption presented the Redlich-Peterson model as the answer that best determines the adsorption isotherm, where the adsorption occurs in monolayer and multilayers. As for the study of adsorption flow, the Chu logistic model is recommended, to determine the necessary parameters of the rupture curves and apply the other models to calculate the adsorption capacity. The Thomas and Yoon-Nelson models showed adsorption capacity values with a mean relative error of 10.38 % and 10.75 %, respectively. © 2022 Elsevier B.V.