ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Assessment of two prop-2-enamide-based polyelectrolytes as property enhancers in aqueous bentonite mud

Robert D. Nagre, Lin Zhao, Isaac K. Frimpong, and Qing-Mei Zhao

College of Petroleum Engineering

E-mail: nagrerobert@yahoo.com

Abstract: Large amounts of hydrocarbons are located in deeper formations where higher temperatures are experienced, hence designing a proper drilling fluid to tolerate such conditions has represented a challenging task for researchers in the field. The current work is focused on evaluating the effectiveness of poly(prop-2-enamide-sodium 2-acrylamido-2-methyl propane sulphonate-ethenyl ethanoate), designated as CP4 and poly(prop-2-enamide-sodium-prop-2-enoate-N,Nʹ-dimethylprop-2-enamide- N-vinylpyrrolidone), denoted as CP5 as additives in water-based drilling fluids. The effect of temperature and salt on the copolymer-incorporated mud properties was examined. The reaction conditions were optimised for synthesis of the terpolymer and tetrapolymer. The chemical structures of copolymers were characterised by Fourier transform infrared (FTIR) spectroscopy. The thermal stability of the copolymers was assessed by thermogravimetric analysis (TGA). Both copolymers exhibited effectiveness in mud viscosity enhancement. The presence of the rigid pyrrole ring in CP5 and the bulky sulphonate side-group in CP4 provided thermal resistance and salt tolerance in their respective copolymer structures. CP4 demonstrated greater fluid-loss reduction by providing 7-fold American Petroleum Institute (API) fluid control and 8-fold high temperature high pressure (HTHP) fluid-loss control at 150°C while CP5 achieved 6-fold control in both parameters in comparison with the blank.

Keywords: HTHP fluid-loss – rheology – terpolymer – tetrapolymer – thermal stability – water-based mud

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0184

Chemical Papers 70 (2) 206–217 (2016)