β‐Cyclodextrin‐functionalized copolymers based on multiple intermolecular forces for enhanced oil recovery

• Published in: Polymer engineering and science Vol. 60; no. 10; pp. 2581 - 2592
• Main Authors: Ren, Hao, Ding, Xiang‐Hua, Luo, Qiang, Yang, Lian‐Yu, Yong, Xiao‐Hua, Wei, Yun, Peng, Jian, Deng, Yong
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.10.2020; Blackwell Publishing Ltd
• Subjects: Acrylamide; Acrylic acid; Calcium ions; Chelation; Copolymers; Cyclodextrins; Enhanced oil recovery; EOR; flow behavior; Fourier transforms; Hydrogen bonding; hydrophobically associative copolymers; Hydrophobicity; Intermolecular forces; multiple intermolecular forces; NMR; Nuclear magnetic resonance; Oil field equipment; Oil fields; Polyacrylamide; Polymer flooding; rheological properties; Thickening; Thixotropy; Viscoelasticity
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.25496

As one of mature enhanced oil recovery (EOR) technologies, polymer flooding has been extensively applied in oilfield. In this study, new hydrophobically associative copolymers were synthesized by free‐radical polymerization of acrylamide (AM), acrylic acid (AA), vinyl‐modified β‐cyclodextrins, and a water‐soluble hydrophobic macromonomer (AA‐APE‐20). Fourier transform infrared, proton‐nuclear magnetic resonance, and scanning electron microscopy verified the structure of hydrophobically associative polymers (HDAPAMs). Compared with partially hydrolyzed polyacrylamide (HPAM), multiple intermolecular forces including chelation between ethoxyl (EO) group and Ca2+/Mg2+, electrostatic bridges between EO groups and carboxyl groups (COO−), hydrogen bonding between EO groups and AM groups (CONH2), hydrophobic association among nonyl phenol groups, and host‐guest inclusion interaction endowed HDAPAMs favorable temperature‐resistance, salt‐resistance, and displacement efficiency. It was found that HDAPAMs showed evident temperature‐response, salt thickening effect, favorable thixotropy, and viscoelasticity. Compared with HPAM, the core flooding experiments demonstrated that HDAPAMs could further enhance 6.97% to 8.43% oil recovery, even after HPAM flooding used. All the results revealed the EOR potential in HDAPAMs flooding.