An Experimental Study of Tapioca Starch-Polyacrylamide Grafted Polymer in Enhanced Oil Recovery

The oil industry is currently facing pressing challenges to increase well productivity.
Both primary and secondary recovery methods can recover up to 30 to 50 % of original
oil in place. In this situation, a tertiary recovery is needed. Polymer flooding is able to
increase the oil production compared to water flooding techniques. Development of a
grafted polymer derived from starch in this research is an alternative to the conventional
polymer flooding. Polymers have been extensively used to solve enhanced oil recovery
(EOR) problems. However, starch as a base biopolymer is suggested as an alternative for
mobility ratio controls and also improvement of polymer properties. This study has been
based on biopolymers flooding and is expected to provide the highest level of oil
recovery. In this case, grafting method between polyacrylamide and starch is applied to
improve some properties ofthe polymer. After grafting, the relative permeability system
(RPS) for lab scale apparatus has been used to determine the percentage of oil production.
After its role in increasing oil displacement, the modified biopolymer is evaluated for its
biodegradation and weathering properties in an accelerated mode (ASTM D5071). We
have employed TGA, XRD, FTIR, FESEM, and DSC to characterize the polymer. Main
bonding has indicates the successful graft between starch and polyacrylamide found at
peak 1600 cm"1 for amide bond formation in biopolymer sample. For biodegradable
effect, the result showed acceleration peak decays of the carbon chain and some forming
carbonyl groups at 1650 cm"1 due to oxidative products formations evidencing
degradation. When this biopolymer compared in the lab scale water flood, it produced a
higher displacement of oil compared to the commercial HPAM and pure starch with
recovery of 16.67 %, 12.5 %, and 10.91 % respectively.