For over one decade the Govt of Nigeria has spent huge sums of money in hydrocarbon exploration of the Nigerian sector of the Chad Basin without success, as no oil or gas discovery has been made in the region. Meanwhile, most researchers and scholars on petroleum potentials in Nigeria have concentrated mostly in the southern basins while little geophysical work has been carried out in the Chad Basin. The book utilizes the Well log data from 23 oil wells in Chad Basin Nigeria to analyze the basin prospect to generate liquid or gas hydrocarbon. The geothermal gradient map of the basin was constructed from bottom hole temperature data.The heat flow values of the various stratigraphic units were then evaluated. Average geothermal gradient of 3.4 oC/100 m within the range of 3.0 to 4.4 oC/100 m was obtained. The oil-generating zone in the basin is expected to occur within the depth range of 1273 m and 4100 m while the average depth to oil floor for the basin is 3626 m. Mean heat flow vary from 63.6 to 105.6 mWm-2, with an average of 80.6 mWm-2. The result serves as a learning guide for students and researchers in the academic and oil industry.