Thermodynamic analysis of micelles formation of anionic surfactant SDS in the presence of aqueous and aqueous solution of ionic liquid 1‐butyl‐3‐methylimidazolium chloride

Impact of the Naturally Driven Surfactant in EOR Application: Experimental, Microscopic, and Numerical Analyses

While synthetic, conventional surfactants have a known negative environmental impact, their high cost poses a significant challenge. In contrast, naturally extracted surfactants are cheaper and are readily available. The applicability of natural surfactants depends on the saponin concentration, extraction, and synthesis methods. Certain parameters, such as their efficiency in obtaining the required interfacial tension (IFT) values, salinity tolerance, and stability under reservoir conditions, must be examined. Kazakhstan produces a substantial quantity of flaxseed, and flaxseed oil is a good source of fatty acids that can be converted to natural surfactants. Therefore, the work aims to identify the potential of the natural-flaxseed oil surfactant. The experimental study evaluated the synthesized surfactant, effective concentration, salinity's effect, interfacial tension, rheology, and oil recovery concerns in vugs limestone. A microscopic study was conducted to provide insight into the flow in the vugus matrix. At the same time, the numerical method was also employed to establish a potential recovery understanding. The Fourier spectrometer results proved the distinct presence of the triterpenoid. The critical micelle concentrations are 6 and 2.5 wt % for solution in 0 and seawater salinity, respectively. The IFT was reduced by 40-48% and is more effective in seawater solutions. The oil additional recovery was 39-50% after surfactants. The presence of a fractured vugus did not affect the success of the application. Despite the difficulty in modeling the system, the numerical results agree with the experiments and show only 7% differences in total recovery. The research offers novel natural surfactants that can be applied in offshore Kazakhstan.

Formation and Phase Transformation of MgCO3·3H2O Whiskers in the Presence of Sodium Dodecyl Sulfate

Huge amounts of MgCl₂·6H₂O are produced annually as a byproduct or waste from KCl production in the Qinghai province of China. An ecological and economic way to solve this problem is transforming the abandoned MgCl₂·6H₂O to valuable MgCO₃·3H₂O whiskers. The formation and phase transformation of MgCO₃·3H₂O whiskers were studied in the crystallization process, in which MgCl₂ and NH₄HCO₃ were precipitated in the presence of sodium dodecyl sulfate (SDS) at 50 °C. Results showed that porous spherical MgCO₃·3H₂O, MgCO₃·3H₂O whiskers, and flocculent rod-like 4MgCO₃·Mg(OH)₂·4H₂O were formed with decreasing concentration of SDS as the crystallization proceeded. When the concentration of SDS was lower than the critical micellar concentration (6.5 mmol·L^-1) at 60 min, SDS was beneficial for the growth in the [010] direction to form one-dimensional MgCO₃·3H₂O whiskers with a high aspect ratio, good uniformity, and a smooth surface (length, 60-70 μm; aspect ratio, 110-140).