Abstarct: Abstract Wettability indicates the tendency of one fluid to spread or adhere to the rock surface in the presence of another fluid, significantly affecting fluid distribution, capillary pressure, flooding, and residual saturation. Evaluating wettability in reservoirs poses a challenge for engineers because no direct measurement method exists. The primary objective of this thesis is to investigate the relationship between wettability and well log data in a field located in the Persian Gulf. The data from one of the wells in this field was examined, encompassing 10 core samples with nuclear magnetic resonance (NMR) data; 5 of these samples included mercury injection capillary pressure (MICP) data, and the remaining 5 were used for validation, which included U.S. Bureau of Mines (USBM) data. In this study, a novel method for qualitatively predicting reservoir wettability is introduced. This method is baxsed on the analysis of MICP laboratory data and the J function, utilizing NMR logs, as well as standard porosity and gamma logs to determine capillary pressure curves. Initially, NMR log data was cross-verified with MICP laboratory data, establishing relationships to determine capillary pressure using NMR logs. Subsequently, porosity and gamma log data were cross-verified with MICP laboratory data, resulting in additional relationships for determining capillary pressure using these common logs. To validate the derived relationships, they were applied to samples with USBM laboratory data. Ultimately, by examining two capillary pressure curves derived from NMR logs and porosity/gamma logs for each core sample, the wettability of these samples was estimated and compared with their USBM data. The results demonstrate that the estimated wettability is reliable, suggesting the viability of this method for industry applications in cases where laboratory information is limited and there is a need to ascertain wettability at various points.