ABSTRACT
This study explores alternative chemical agents to enhance oil recovery in sandstone and carbonate reservoirs, aiming to address limitations in alkali-surfactant-polymer (ASP) flooding. Existing ASP methods face technical and environmental challenges, prompting research into alternative chemical agents. However, there are limited field deployments of these alternative chemical agents due to high costs, and ternary combinations of these agents remain unexplored. The study investigates a combination of organic alkali, amino acid-based surfactant/surface-active ionic liquid, and biopolymer. Comparative analysis with conventional ASP formulations reveals promising results. Organic alkali and biopolymer combination mitigates the adverse effects of inorganic alkalis on partially hydrolyzed polyacrylamide, enhancing the oil recovery potential. A unit technical cost (UTC) calculation showed that despite higher chemical costs per incremental barrel of oil, the alternative ASP formulations demonstrate comparable costs due to reduced facility cost. Cost-effectiveness will improve with incorporation of factors such as environmental friendliness and reduced preflush requirements. Mass production of these agents could further enhance the economic feasibility. Therefore, this study reveals that careful cost-benefit analysis, the development of low-concentration formulations, and mass production of these chemical agents could facilitate the implementation of these alternatives, ensuring compliance with environmental regulations and enabling ASP flooding in challenging reservoir conditions.
ABSTRACT
Plant extracts have been shown to effectively inhibit metal corrosion. Using the Box-Behnken design, gravimetric, and electrochemical techniques, analyses were designed to investigate the anti-corrosion potential of okra in a 1M HCl medium. The inhibition performances derived from the various methods were in good agreement, demonstrating that physio-chemisorption was effective and adhered to the Langmuir isotherm model. The efficiency of okra mucilage extract was 96% at a much lower concentration compared to 91.2% and 88.4% for the unsieved extract and gelly-okra filtrate, respectively. FTIR results showed the presence of several functional groups in the okra mucilage extract that are associated with adsorption, and TGA analysis revealed that the extract has high thermal stability. FESEM analysis also supported evidence of adsorption. It was determined that corrosion inhibition by okra mucilage extract was primarily influenced by temperature, followed by extract concentration, with immersion time having the least effect. From the model optimization, it was observed that okra mucilage extract at 200 ppm, 60°C, and 24 h gave an inhibition efficiency of 89.98% and high desirability. These results demonstrate the high capacity of natural okra as an efficient biodegradable corrosion inhibitor.
Subject(s)
Abelmoschus , Steel , Corrosion , Acids , Plant Extracts , PolysaccharidesABSTRACT
Introduction: Natural plant polymers demonstrate effective corrosion inhibition abilities, because of their numerous binding sites and excellent adsorption abilities. Methodology: In this study, the Box-Behnken method, gravimetric and electrochemical analyses were used to design and investigate the corrosion inhibition potential of a modified graft polymer of okra for mild steel in a 1M HCl medium. The influence of inhibitor concentration, temperature, and time were also investigated. Qualitatively, the Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetric Analysis (TGA), and Field emission scanning electron microscopy (FESEM) were used to characterize the extracts and evaluate the metal's surface morphology. Results and discussion: The quantitative analyses showed that the modified natural polymer's inhibition efficiency (IE) increased with concentration and reached 73.5% at 800 ppm, with a mixed-type mode of inhibition. From the response surface methodology, it was revealed that temperature influences the IE more than concentration and immersion time. The optimized IE using the desirability function showed the possibility of attaining 88.2% inhibition with inhibitor concentration at 142.3 ppm, temperature at 60.4°C, and an immersion time of 22.4 h. The new functional groups in the hybrid polymer revealed by FTIR analysis shows that grafting improved the inhibitor's adsorption abilities. TGA analysis confirmed the extract's high thermal stability, which highlights the inhibitor's strong adsorption and efficiency for high temperatures. FESEM analysis indicated evidence of inhibitor adsorption onto the metal surface. Conclusion: These findings suggest that the grafting of okra with acrylamide enhances its inhibition properties and contributes to its functionality as a cost-effective plant-based alternative inhibitor against corrosion for mild steel facilities.
ABSTRACT
Combinatory flooding techniques evolved over the years to mitigate various limitations associated with unitary flooding techniques and to enhance their performance as well. This study investigates the potential of a combination of 1-hexadecyl-3-methyl imidazolium bromide (C16mimBr) and monoethanolamine (ETA) as an alkali-surfactant (AS) formulation for enhanced oil recovery. The study is conducted comparative to a conventional combination of cetyltrimethylammonium bromide (CTAB) and sodium metaborate (NaBO2). The study confirmed that C16mimBr and CTAB have similar aggregation behaviors and surface activities. The ETA-C16mimBr system proved to be compatible with brine containing an appreciable concentration of divalent cations. Studies on interfacial properties showed that the ETA-C16mimBr system exhibited an improved IFT reduction capability better than the NaBO2-CTAB system, attaining an ultra-low IFT of 7.6 × 10-3 mN/m. The IFT reduction performance of the ETA-C16mimBr system was improved in the presence of salt, attaining an ultra-low IFT of 2.3 × 10-3 mN/m. The system also maintained an ultra-low IFT even in high salinity conditions of 15 wt% NaCl concentration. Synergism was evident for the ETA-C16mimBr system also in altering the carbonate rock surface, while the wetting power of CTAB was not improved by the addition of NaBO2. Both the ETA-C16mimBr and NaBO2-CTAB systems proved to form stable emulsions even at elevated temperatures. This study, therefore, reveals that a combination of surface-active ionic liquid and organic alkali has excellent potential in enhancing the oil recovery in carbonate reservoirs at high salinity, high-temperature conditions in carbonate formations.
