Petroleum Research Petroleum Research 2019(October-November), Vol. 29, No. 107, 40-43 DOI: 10.22078/pr.2019.3256.2555 Synthesis and Characterization of Acrylamide-Based Homo-and Copolymers and Their Application in Water-Based Drilling Fluid Hossein Biazar 1 , Mahdi Abdollahi* 1 , and Alireza Nasiri 2 1. Polymer Reaction Engineering Department, Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, Iran 2. Petroleum Engineering Division, Research Insitute of Petroleum Indusry, Tehran, Iran abdollahim@modares.ac.ir DOI: 10.22078/pr.2019.3256.2555 Received: July/03/2018 Accepted: March/12/2019 INTRODUCTION Water-based drilling fuid (WBDF) is a colloidal dispersion containing matrix, solid and chemical phases, and its roles in during drilling process are transferring drilled cutng to surface, forming flter cake on the well, cooling and bit lubricatng [1]. Hydrophilic polymers are one of the most important polymers used in drilling fuid (DF), controlling the fuid viscosity and reducing the fuid loss. Among other hydrophilic polymers, partally hydrolyzed polyacrylamide (PHPA) is able to increase fuid viscosity at low concentratons due to its high hydrophilicity and high molecular weight. However, this polymer has not a good resistant against harsh operaton conditons such as high salinity and temperature. It has been shown in the previous works that incorporatng a small amount of hydrophobic monomers into the hydrophilic acrylamide (AM) chains results in the three-dimensional physical networks via hydrophobic associatons, leading to signifcant increase in the aqueous soluton viscosity [2]. In the present study, polyacrylamide homopoly- mer and acrylamide/styrene (AM/St) copolymer were synthesized via micellar copolymerizaton method and then characterized. Based on the lit- erature, copolymers synthesized via this method have a multblock structure as a hydrophobic blocks incorporated into the hydrophilic chains. Finally, efect of presence of synthesized poly- mers in the WBDF was investgated. EXPERIMENTAL PROCEDURE SYNTHESIS OF ACRYLAMIDE-BASED HOMO- AND COPOLYMERS First, 1.2 g AM, for synthesis of homopolymer (P1), and 1.1702 g AM and 0.0298 g St, for synthesis of copolymer (P2), were added to 40 ml distlled water. Afer dissoluton, 20 mg ammonium persulfate as an initator was added