The quest for cleaner sources of energy in the world today has paved way for scientists and researchers to delve into renewable energies like the geothermal energy. Researches on the enormous potential that a geothermal reservoir could posses are currently underway. However, there is limited information on the quantity and quality of geothermal reserves in Nigeria. Extraction of this geothermal heat will improve power generation and the availability of scarce electricity in Nigeria. This work is aimed at using a mathematical model to estimate the quantity of recoverable heat by first estimating the total heat in place and then the heat losses associated with heat transfer in a wellbore. In this work, we were able to ascertain the heat in place as well as recoverable geothermal heat for geothermal regions in Nigeria having a temperature-at-a depth range of 50°C – 110°C and also a higher temperature-at-a depth range of 150°C – 250°C. Heat losses were considered for pipe tubings with 1 inch, 2 inches and, 3 inches diameter. A higher recoverable of 92% was gotten when the 1 inch pipe diameter was used. 87% and 76% recoverable were also gotten when the 2 inches and 3 inches diameters were used respectively. Nigeria has the potential of generating 74Megawatts of electricity from just one geothermal reservoir which could provide electricity for villages and small towns.