Abstract
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%.
Highlights
Chemical enhanced oil recovery (EOR) techniques are usually used as additives for hydrocarbon production due to its simplicity and relatively reasonable additional production costs (Wang 2003; Sheng 2010; Olajire 2014; Hassan et al 2017 and 2019)
This study experimentally investigated rheological properties of a natural polymer obtained from guar gum and salinity brine with consideration of high salinity and high temperature (20% NaCl and 210 °F), respectively, and tested the guar gum solution as promising EOR polymer in sandstone reservoirs
The results showed good stability of guar gum polymer even at high temperature where more than 100 cp viscosity can be achieved at 210° F at 7.34S−1 shear rate for polymer prepared in deionized water (Fig. 6)
Summary
Chemical EOR techniques are usually used as additives for hydrocarbon production due to its simplicity and relatively reasonable additional production costs (Wang 2003; Sheng 2010; Olajire 2014; Hassan et al 2017 and 2019). Water-soluble polymers are widely used in petroleum field operations like well-drilling, hydraulic fracturing fluids, and EOR processes (Huggins 1942; Nasr-El-Din and Noy 1992; Wei Yu et al 2014; Andrew et al 2016; Almansour et al 2017; Lee and Lee 2019). Guar gum is a seed endosperm portion gained from the cluster bean herbal. It generally comprises of high molecular weight polysaccharides of galactomannans ranges between 0.1 and 2.8 million which are a linear chain of (1 → 4)-linked β-D-mannopyranosyl units with (1 → 6)-linked α-D-galactopyranosyl remains as side chains (Mudgil et al 2014). The efficiency of polymer solutions highly depends on its rheological properties (NasrEl-Din et al 1991; Taylor et al 1998; Airey 2003; Kim et al 2010; Jang et al 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
