Nanofluid of Petroleum Sulfonate Nanocapsules for Enhanced Oil Recovery in High-Temperature and High-Salinity Reservoirs

Abstract

Petroleum sulfonate (PS) salt surfactants that are insoluble in high-salinity water were encapsulated into 10–60 nm oil swollen micelles dispersed by a cocamidopropyl hydroxysultaine zwitterionic cosurfactant to form a highly stable nanofluid at elevated salinity (∼56 000 mg/L) and temperature (∼100 °C). The resulting “Nano-Surfactant (NS)” fluid enables an economic, efficient, and environmentally friendly enhanced oil recovery (EOR) capable of targeted delivery of PS salt surfactantsone of the most abundant and inexpensive industrial surfactants, yet cannot be used in most EOR operations because of its insolubility in high-salinity waterto residual oil without the need of massive amounts of surfactants. The NS formulations presented here can be easily prepared in the field by a simple one-pot, one-step procedure at ambient temperatures and with a minimal energy input. This article reports the preparation method of the NS and results, demonstrating their long-term colloidal and chemical stability at 100 °C, reduction of crude oil–high-salinity water interfacial tension (IFT) by 3 orders of magnitude (from ∼10 to 0.008 mN/m), and improved mobilization of the trapped crude oil from the carbonate rock. Results point out the potential of NS formulations in enhancing oil mobilization under a variety of reservoir conditions. The NS platform described here can be utilized to encapsulate and deliver a variety of other chemical treatments, not only in oil recovery applications but also in others such as remediation of nonaqueous phase liquid-contaminated groundwater aquifers, well-drilling operations, and wellbore stimulation.

Specific Ion Effects at Calcite Surface Defects Impact Nanomaterial Adhesion

“…Calcium carbonate (CaCO 3 ) is a widely important mineral that is found extensively in biological and geological systems. The interaction of water, ions, organic molecules, macromolecules, and nanomaterials with calcite surfaces controls a broad range of natural and industrial processes such as ion exchange, contaminant migration, , enhanced oil recovery, − biomineralization, − and flocculation . Atomic force microscopy (AFM) is a powerful tool to study calcite surface interactions in air and in solution because of its Angstrom-level spatial and pico-Newton force resolutions.…”

Molecular Assembly of Surfactant Mixtures in Oil-Swollen Micelles: Implications for High Salinity Colloidal Stability

“…Recent experiments have identified that trace amount of mineral oils may result in better high salinity colloidal stability of the surfactant mixtures . We hypothesize that the inclusion of oils (decane) can form larger oil-swollen micelles with stronger cosurfactant shielding (Figures D,E and B,D) compared to smaller micelles with weaker cosurfactant shielding (Figures B,C and B) for the sulfonates and resulted in more colloidally stable formulations in high salinity.…”

High-temperature high-pressure microfluidic system for rapid screening of supercritical CO2 foaming agents

“…Phase 2 of the microfluidic experiments was aimed to further evaluate the best-performing formulations from Phase 1 in singlicate: Duomeen TTM, Amphosol LB, and Amphosol CG-50. Petrostep SB was also selected for further evaluation due to its zwitterionic chemical structure with favorable stability and transport properties in high-salinity and high-temperature carbonate reservoirs 48 . In Phase 2 of the experiments, CO 2 foams were evaluated at surfactant concentrations of 0.5, 0.2, 0.1, and 0.05 wt% in Brine 1, at 50%, 70%, and 80% foam qualities.…”