Temperature-Dependent Mitigation of Sodium Lignosulfonate Adsorption on Buff Berea Sandstone Using Silica Nanoparticles for Chemical Enhanced Oil Recovery

Surfactant adsorption on reservoir rock is a major limitation in chemical enhanced oil recovery (EOR) because it reduces effective surfactant concentration and increases chemical loss. In this study, a sodium lignosulfonate (SLS)-silica nanoparticle (SNP) system was investigated on Buff Berea Sandstone (BBS) at different temperature mitigations to evaluate its potential for adsorption. Residual surfactant concentration was determined by UV-Vis spectrophotometry at 208 nm, yielding excellent linearity R2 = 0.9948. Adsorption equilibrium was analyzed using Langmuir and the Freundlich isotherm models, while kinetics were evaluated using pseudo-first-order (PFO) and pseudo-second-order (PSO) models. At 30 °C, adsorption was best described by the Langmuir model (R2 = 0.9619, SSE = 2.09, whereas at 60 °C, the Freundlich model gave the best fit (R2 = 0.8220, SSE = 0.36). The optimum SNP concentration increased from 1000 to 1500 mg/L at 30 °C to 2000–2500 mg/L at 60 °C, likely due to elevated temperature, which enhanced molecular mobility and interfacial heterogeneity, thereby requiring more SNPs to cover or shield active adsorption sites on BBS. Kinetic results consistently favored the PSO model. These findings show that SNPs effectively reduce SLS adsorption and modify the adsorption behavior in a temperature-dependent manner, providing useful insight for the design of more efficient chemical-enhanced oil recovery formulations.