Synthesis and Evaluation of a New Polymeric Retarder for Enhanced Cement Slurry Stability in Oil Well Applications

ABSTRACT As global energy demand escalates, drilling activities extend to greater depths, necessitating the use of specialized cement additives to guarantee safe cementing operations, especially in challenging downhole environments. This study introduces a novel terpolymer, designated as AM‐IT‐AS, synthesized through free radical polymerization. It comprises 2‐acrylamido‐2‐methylpropane sulfonic acid, itaconic acid, and acrylamide monomers in a molar ratio of 1:0.2:0.2. The synthesis process was verified using Nuclear Magnetic Resonance (NMR) and Fourier‐Transform Infrared (FT‐IR) spectroscopy, while thermogravimetric analysis (TGA) was employed to assess thermal stability, revealing significant decomposition initiation above 200°C. The primary focus was to evaluate AM‐IT‐AS as a high‐temperature and high‐pressure (HTHP) retarder suitable for oil well cement applications. Results demonstrated that the terpolymer effectively retarded cement setting, achieving an 8.5‐h delay at 121°C (250°F) and 3000 psi with only 1% by weight of cement. Notably, incorporating AM‐IT‐AS reduced plastic viscosity by 24%, enhanced gel strength by 62%, and increased compressive strength by 57%, compared to cement without the additive. These findings highlight the potential of AM‐IT‐AS as a promising retarder for HTHP oil well cementing, offering improved performance and operational safety in demanding environments.