Applications of highly salt and highly temperature resistance terpolymer of acrylamide/styrene/maleic anhydride monomers as a rheological modifier: Rheological and corrosion protection properties studies

Due to the weak performance of commercially affordable natural and synthetic polymeric thickeners in high temperatures and salinity, they fail to use in many applications especially in saline conditions with high temperatures. In this work, a new salt and temperature resistance acrylamide/styrene/maleic anhydride terpolymer (PASM-t) with self-associative properties was synthesized via a one-step inverse emulsion polymerization and its applicability as a rheological modifier and thickener was investigated. The characteristics of synthesized PASM-t (s-PASM-t) and its aqueous solutions were investigated using FT-IR, FE-SEM, GPC and rheometric mechanical spectrometry (RMS) analyses. The rheological investigations revealed that the shear viscosity of aqueous increases with the increment of temperature (from 30 °C to 80 °C) and salt concentration (from 5000 to ‌50000 ppm). High-temperature aging test at 150 °C for 12 h of terpolymer aqueous solutions was revealed the unique dramatical increment of rheological properties promoted in the presence of the salt. Rheological behavior and corrosion protection properties of bentonite-based drilling fluid containing s-PASM-t were investigated and results were compared with those of the neat mud and the mud containing commercial carboxymethyl cellulose (CMC). Presented results showed that the s-PASM-t modified mud and shows the better rheological and corrosion resistance performance.