A study of a new polymeric retarder for enhanced rheology and its effects on properties of oil well cement

Increasing energy needs are driving the drilling of deep oil and gas wells, which require specific cement additives for slurry placement and strength development in challenging downhole environments. Among these, retarder is a critical component in the assurance of the safety of the cementing operation. In this study, a solution polymerization-based high-temperature polymeric retarder (named as NH5) including N-[3-(Dimethylamino)propyl]acrylamide/sodium styrene sulfonate/itaconic acid was produced. The synthesis of NH5 was validated through nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), and powder X-ray Diffraction (PXRD) analyses, with the polymer exhibiting a decomposition temperature of approximately 380 ℃. Following the preparation of four samples NH5, NH5S (polymer with silica flour), R (commercial retarder), and RS (commercial retarder with silica flour), the effects of these samples on rheological parameters, petrophysical and mechanical characteristics, and thickening time, were investigated. When compared with R, NH5 exhibited 63.4 % reduction in plastic viscosity, 94 % decrease in permeability, and 39.90 % enhancement in compressive strength. The thickening time of cement slurry containing NH5 was 450 min at 121°C (250 °F) and 10,000 psi. The findings suggest that NH5 could serve as a suitable alternative for traditional oil well cement.