A Systematic Study on the Impact of Surfactant Chain Length on Dynamic Interfacial Properties in Porous Media: Implications for Enhanced Oil Recovery

Abstract

We propose a new systematic procedure to investigate the effect of hydrophobic and hydrophilic chain lengths of polyoxyethylenated (POE) nonionic surfactants on dynamic interfacial properties in porous media. We study the impact of nonionic surfactant structure on oil recovery through comprehensive experimental measurements of phase behavior, cloud point, dynamic interfacial tension, dynamic contact angle, and spontaneous and forced imbibitions at ambient and reservoir conditions. We identify a surfactant structure that increased the oil production by 22% and 6% compared to tap water and a nonionic surfactant commercially deployed in a major unconventional oil reservoir, respectively. In this work, we observe that factors such as minimum interfacial tension used for surfactant selection are not the only parameters influencing displacements at the pore scale. The results of this study reveal that when a surfactant solution imbibes into the pore space as an invading phase, the surfactant ability to lower the IFT and reach equilibrium faster plays an important role in the local trapping of oil phase on a pore-by-pore basis. We propose a mechanism relating this surfactant behavior to oil−brine displacement and confirm our results by visual observation of in situ pore fluid occupancies after surfactant imbibition in micromodels and naturally occurring porous media.

Design and Tuning of Nanofluids Applied to Chemical Enhanced Oil Recovery Based on the Surfactant–Nanoparticle–Brine Interaction: From Laboratory Experiments to Oil Field Application

“…For SA, the functional groups C-H located from 2800 to 3000 cm −1 were of a lower intensity than for SB, suggesting short chains of aliphatic groups which may increase the dipole moment of surfactant molecules and decrease the steric effects that restrict nanoparticle interactions with the sulfonated groups of the surfactants (1180-1245 cm −1 bands). As previously reported [86,87], an increase in hydrocarbons chain is directly related to hydrophobic character and further solubility in the oil phase disfavoring the balance of micelle formation in the interphase. In energetic terms, the increase in hydrophobicity reduces the enthalpy and increases the entropy of the process affecting the interfacial adsorption [88].…”

Salt Precipitation in Ultratight Porous Media and Its Impact on Pore Connectivity and Hydraulic Conductivity

“…The results of previous rock characterization performed on similar core samples from the same reservoir show the samples to be clay‐rich, tight dolomitic siltstone with insignificant organic‐matter content (Sarg, ; Saraji & Piri, ). Mineral maps of these samples exhibited mineralogies consisting primarily of calcite, dolomite, quartz, pyrite, and illite (Huina et al, ; Mirchi et al, ; Sarg, ; Saraji & Piri, ).…”

Nanoparticle-stabilized microemulsions for enhanced oil recovery from heterogeneous rocks

“…The addition of MENP into the brine contributed to a faster reduction in the threshold capillary pressure upon contact with NAPL (Figures 4,5), resulting in a higher amount of NAPL mobilization. 65 The superior ability of MENP to restore the wettability of surfaces (especially in carbonates) also led to a higher solubilization propensity (Figures 6,7). Figure 9 reveals that MENP was able to remove NAPL from small capillary elements (small pores, corners of large pores, micropores in cement, and pores with complex geometry).…”