Chemical enhanced oil recovery (EOR) processes are usually used as additives for hydrocarbon production due to its simplicity and relatively reasonable additional production costs. Polymer flooding uses polymer solutions to increase oil recovery by decreasing the water/oil mobility ratio by increasing the viscosity of the displacing water. The commonly used synthetic water-soluble polymer in EOR application is partially hydrolyzed polyacrylamide (HPAM). However, synthetic polymers in general are not attractive because of high cost, environmental concerns, limitation in high temperature, and high-salinity environment. Guar gum is an environmentally friendly natural water-soluble polymer available in large quantities in many countries and widely used in various applications in the oil and gas industry especially in drilling fluids and hydraulic fracturing operations; however, very limited studies investigated on guar as a polymer for EOR and no any study investigated on its uses in high-temperature and high -salinity reservoirs. The objective of this study is to confirm the use of guar gum as a natural polymer for EOR applications in sandstone reservoirs and investigate its applicability for high-temperature and high-salinity reservoirs. The study experimentally investigated rheological characteristics of a natural polymer obtained from guar gum with consideration of high temperature (up to 210 °F) and high salinity (up to 20% NaCl) and tested the guar solution as EOR polymer. The results of this study show that the guar solution can be used as an environmentally friendly polymer to enhance oil recovery. Based on the results, it can be concluded that guar gum shows shear-thinning behavior and strongly susceptible to microbial degradation but also shows a very good properties stability in high temperature and salinity, where in low shear rate case, about 100 cp viscosity can be achieved at 210 °F for polymer prepared in deionized water. Guar polymer shows good viscosity in the presence of 20% NaCl where the viscosity is acceptable for temperature less than 190 °F. Also, the flooding experiment shows that the recovery factor can be increased by 16%.

Cyclic Steam Stimulation (CSS) is a crucial thermal Enhanced Oil Recovery (EOR) technique for heavy crude oil. However, its effectiveness depends on precise parameter optimization and operational design, with CO₂ gas emissions during steam generation often overlooked. This study thoroughly evaluates CSS effectiveness in a heavy oil sandstone reservoir, focusing on eight selected CSS wells. Three of these wells were compared to three wells producing with primary recovery (cold wells), all from the same layer and sharing identical facies and heterogeneity systems. The investigation employs the Chan model to diagnose excessive water production and analyzes well bottom hole pressures using the hydrostatic pressure formula. A novel process is introduced to calculate CO₂ gas emissions from each CSS well's steam generator based on the total energy required for a CSS cycle, measured in Mega Joules (MJ). The comparative analysis reveals that, after five years, total oil production from the CSS wells is 13%, 25%, and 17% lower than that from the cold wells, despite an increase in the cumulative steam injection of 4%, 60%, and 44% for wells 2, 4, and 6, respectively. Additionally, cumulative water production (Wp) from the three CSS wells over the five years is 76% higher than from the cold wells. The combined financial gain from the three CSS wells is only 15.7% of the profit from the three cold wells. CO₂ gas emissions per oil barrel increased with each cycle for the CSS wells. In summary, the results highlight the substantial CO₂ gas emissions associated with CSS operations, underscoring the need for careful consideration in the CSS design process. Despite CSS's effectiveness in enhancing heavy oil recovery, potential drawbacks such as steam channeling and excessive water production necessitate caution. Therefore, continuous review of CSS implementation and exploration of alternative strategies, including a combination of EOR methods and steam additives, are recommended to improve long-term CSS efficiency.

This paper deals with on line viscosity measurements using integrated circuit technology, and is building on a previous paper on the use radio frequency identifier (RFID) technology for determining dielectric coefficients. It is asserted that the progress in RFID technology and integrated circuits, in particular in micro–electro–mechanical system (MEMS) makes it possible to combine them to perform physico-chemical property measurements using devices on centimeter scale. It can even be expected that these devices can be made increasingly smaller. An important property of interest is the viscosity, in this specific case, for the use of Arabic gum in enhanced oil recovery. Arabic gum, is an environmentally acceptable natural product. Natural-polymer solutions 1000 [ppm] are more viscous and therefore more efficient oil displacement agents. They require less invested exergy than non-viscosified water to recover oil. However, polymers, in particular environmentally acceptable natural-polymers (e.g., Guar–Arabic gum) available in large quantities in India and Sudan, are susceptible to microbial degradation. It is therefore important to monitor its quality at the injection and production side for real-time quality control. Natural-polymers based on plant products are promising EOR agents. They may have a lower environmental footprint because of the biodegradability. To provide a proof of concept, we use a state of the art acoustic wave sensor (AWS), which can determine acoustic viscosities. It is asserted that RFID technology can be used to record the acoustic wave signal (SenGenuity vismart acoustic wave Sensor AWS) to determine the viscosity at some distance (meters) away from the measurement device. A calibration with solutions of known viscosity behavior (i.e., Glycerol) can be used to relate the acoustic viscosity to the dynamic viscosity. We can calibrate the acoustic wave sensor using Guar–Arabic gum solutions to measurements with the Anton Paar viscometer (MCR-302). For the glycerol solution we also compare to reported literature data. The Newtonian viscosity measurements of the Paar density meter, and the literature values agree within a few percent. These favorable comparisons, are an important step in developing a methodology that allows cutting edge RFID-IC technology for real-time non-contact monitoring of viscosity degradation.