A proper slurry design is critical to cementing work success. In the present investigation, a ball mill method was utilized for preparing a nano powder from a cement dust material, supplied via Al-Kufa Cement Factory, to reinforce the oil well cement by utilizing it as a partial replacement of oil well cement class (G) using different weight percentages (0.25%, 0.5%, 0.75% and 1%). A mixture having water to cement ratio of (0.44) was produced. The produced samples characterizations were achieved via the Atomic Force Microscope (AFM), the X-Ray Diffraction (XRD) as well as the density and compressive strength. Results showed that the structural characteristics were enhanced with the phase formation of the calcium silicate hydration (C-S-H), and both density and compressive strength were improved. Accordingly, obtained results suggest that the modified cement is suitable for the oil well uses.