The oil and gas industry faces a great challenge and loss due to corrosion in the sweet aggressive medium. To overcome this effect addition of corrosion inhibitors, especially eco-friendly ones, are the prime additive. The description in this paper includes the synthesis of nano-sized novel polymeric composite material of SiO2, i.e., n-SiO2/P (ANA), and its application as a sweet corrosion inhibitor (3.5 wt% NaCl saturated with CO2) for J55 steel. The characterization of synthesized n-SiO2/P (ANA) was done via spectroscopic techniques. The chemical and electrochemical methods were used to evaluate the inhibitive performance. The surface texture of both protected and corroded samples was analyzed via scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). The results of EIS and PDP reveal the increase in Rct values with the rising amount of n-SiO2/P (ANA) and the anodic nature of n-SiO2/P (ANA) inhibiting action. The maximum inhibitive performance result is 92% at 400 mg/L. The Langmuir plot supports the best fitting experimental data. The surface study supports the n-SiO2/P (ANA) covering onto J55 steel.