Effect of Salt on <i>Grewia Mollis</i> Gum as Biopolymer Drag Reducing Agent in Slickwater Fracturing

The search for lower-cost materials that reduce pressure drop in fluid transportation in hydraulic fracturing is of paramount importance. Polymers are known to reduce pressure drop in pipeline flows in a hydraulic fracturing process referred to as friction reducers (drag reducing agents). Drag reducing agents are usually synthetic or natural polymers such as partially hydrolyzed polyacrylamide, polyethylene oxide, Guar gum, xanthan gum. The performance of these polymers as drag reducing agents on pressure gradient (pressure drop; Δp) in pipes are significantly affected by high temperature and salinity. This work focused on the investigation of effects of salinity on a natural polymer - Grewia Mollis gum as a drag reducing agent in slickwater fracturing. The sample of Grewia gum was obtained and mucilage was extracted from the inner stem bark by maceration in distilled water at room temperature. XRF and FTIR were conducted to characterize the sample and then the percentage drag reduction of the polymer were determined in the flow loop setup.  To establish the baseline for this work, the percentage drag reduction was conducted first by dissolving the polymer in fresh water and then followed by dissolving in 1000 ppm and 5000 ppm of NaCl. Drag reduction results revealed that the drag reduction performance in freshwater is better with the value of 25% at minimum flow rate of 2.5 m3 / hr and 42.5 % at maximum flow rate of 4.5 m3 /hr in brine solution, the drag reduction performance of 21.25% at 200 ppm in brine solution of 1000 ppm was reduced to 20.60% and reduced to 20 % with increase in brine solution to 5000 ppm at flow rate of 4.5 m3 / hr. It can be concluded that the percentage drag reduction was affected when salts were introduced into flowing fluid.