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Chemical enhanced oil recovery (EOR) using polymers has been very successful in reservoirs with favorable reservoir environments. However, chemical flooding in high-temperature (HT; 80 degrees C), high-salinity (30,000 ppm) reservoirs faces challenges due to poor polymer/ surfactant stability. Despite numerous studies on polymer-based EOR fluids, limited attention has been given to hybrid systems combining surfactants, hydrophobically associated polymers, and nanoparticles. In this work, a combination of experimental and molecular dynamics (MD) simulation methods was used to develop and evaluate a hybrid nanofluid using hydrophobically associative polymer (HAP; AP-P4), surfactant [sodium dodecylsulfate (SDS)], and silica nanoparticles (SiO2). The optimal formulation (0.18% AP-P4, 0.3% SDS, 0.1% SiO2) exhibited strong stability (zeta potential = -32 mV), reduced interfacial tension (IFT; 0.42 mN/m), and wettability alteration (theta = 116-23 degrees). The comparison of Fourier transform infrared spectroscopy (FTIR) spectra of pure SiO2, AP-P4 with hybrid fluid highlighted the physical rather than chemical interaction in the nanofluid. Viscosity loss of only 38.2% under HT conditions was recorded. Furthermore, MD simulation parameters, such as radial distribution function (RDF), mean square displacement (MSD), and binding energy, revealed strong AP-P4 and SiO2 interactions, improving stability and viscoelasticity, while AP-P4 and SDS enhance injectivity. Coreflooding tests showed a 14.1% oil recovery increase post-waterflooding, with good injectivity (resistance factor = 1.54, residual resistance factor = 1.15) and minimal permeability damage. This hybrid nanofluid offers a promising EOR solution for HT and high-salinity reservoirs, combining stability, mobility control, and improved displacement efficiency.
This article describes the development and testing of a new low cost, streamlined gas to liquids(GTL) process named Cool GTL TM to make drop in sustainable aviation fuel (SAF) from bioderived gas or carbon dioxide and hydrogen. This system uses an improved catalyst in the reformer, Fischer Tropsch and upgrading reactor and an electric reformer. The Cool GTL system is simplified compared to the commercial state of the art. The Cool GTL system requires no membranes to adjust the compositions of synthesis gas and the vapor product from the Fischer Tropsch reactor goes directly to the upgrading reactor without removing the CO. The liquid hydrocarbon product made from this streamlined system is 50% high quality SAF meeting all SAF specification including freeze point. Trace levels of wax are produced which can be recycled to extinction. A novel electrically heated reformer was tested in the integrated system which uses internal resistive heaters in a bed of catalyst. This design eliminates the need for a pre-reformer for C2+ since the feed enters the catalyst bed at 537 °C and the temperature is increased in the reformer reactor through the internal heaters to reach the 808°C. The electric reformer is 10 percent of the size of a reformer using a furnace. By using bi-reforming catalyst both methane, C2+ and carbon dioxide can be converted to synthesis gas with a H2/CO ratio of 2.0-2.5 which can be fed directly to the Fisher Tropsch reactor without membranes to adjust the H2/CO ratio. More than 24 gallons of SAF was made using this integrated, simple, low cost, compact system. Statement of Industrial Relevance: This testing demonstrated a simplified streamlined GTL process which can be used to make SAF at small scales. Novelty or Significance : The Cool GTL is a new streamlined approach to converting biogas, bioderived gas or CO2 to SAF.
