Nano-suspension combined effect with polymer gels for enhanced oil recovery in low permeability reservoir

Since the last decades, the enhanced oil recovery (EOR) techniques have commonly been utilized to recover the residual oil from the reservoirs by applying primary and secondary recovery methods. However, due to reservoir complexity such techniques containing new materials and additives, the implementation of technology is challenging. In this experimental study, the nano-suspensions were combined with different polymers and their effective role in improving the oil recovery was investigated. Three different hydrolyzed poly-acrylamide (HPAM) polymers, i.e., HPAM-882, HPAM-60512, and HPAM-854, were incorporated, and two different types of nano-suspensions, i.e., KY-100 and KY-200, were taken, and then, the best polymer and nano-suspensions among them was selected. Then, further, the different combinations of slug injection were tested in low permeability sand pack models. After that, four different injection schemes were developed and their results were compared. In scheme A, two nano-suspensions (KY-100 and KY-200) and three polymers (HPAM-882, HPAM-60512, and HPAM-854) with 0.5 pore volume (PV) as a single slug were injected for flooding experiments in sand-pack. In Scheme B, the total 0.5 PV slug was injected in which 0.3PV was the front slug of nano-suspensions KY-100 and 0.2 PV was the back slug of polymer gel HPAM-60512. In scheme C, 0.3 PV was injected as front slug of polymer gel HPAM-60512 and 0.2 PV was he back slug of nano-suspensions KY-100. In scheme D, 0.5 PV mixed slug of nano-suspensions KY-100 and polymer gel HPAM-60512 was injected. Result revealed from this study that the nanoparticles suspended in water combined with polymer gel as different slug combinations is a promising method to improve the oil recovery from low permeability reservoirs. Scheme B was comparatively the best option than schemes A, C, and D. The combinations of nano-suspensions with polymers might provide a better platform for further investigations in low permeability reservoirs.