Different analytical techniques, including API gravity; sulfur-nickel-vanadium contents; liquid chromatographic separation; and gas chromatography, were utilized to investigate oil families of three crude oils collected from Bakr oilfield of middle-lower Miocene age and characterized by limestone facies at various depth locations in the central Gulf of Suez. These geochemical aspects were used to assess source input and maturation of oil families. The results showed that the studied oils indicate a close genetic relationship between studied crude oils, and classified as aromatic intermediate oils. These types of oils are characterized by mature sources derived mainly from marine inputs such as biomass from algae and plankton from different saline environments.