The aim of this study was to investigate the surface free energy on the surface of calcite rock and also on the surface of aged calcite in Surfapore Nanofluid using a contact angle measurement. For this purpose, calcite surfaces were prepared by cutting to an approximate size of 3×3×0.4cm³ and grinded and polished to achieve different roughnesses. The purity and roughness of the samples were determined by X-ray diffraction and atomic force microscopy, respectively. Using the static contact angle on the surface of calcite and calcite aged in the Nanofluid, surface energy determined by three methods of geometric mean, arithmetic mean and Zisman plot showed surface free energy between 30-40mN/m, and polar forces overcome dispersion at calcite surface. After aging calcite surface in the Nanofluid, surface energy reached less than 12mN/m. This surface free energy reduction indicates an increase in the contact angle of the fluids on the aged calcite surface in the Nanofluid. The results of this study will help to better understand the surface properties of calcite in the presence of Nanofluid, as well as how to change its wettability to gas wet conditions, taking into account the static contact angle.