Geothermal energy potential from analysis of aeromagnetic data of part of the Niger-delta basin, southern Nigeria

Abstract

In the quest for alternative or renewable energy resource, attention is being focused on geothermal energy within some parts of the Niger Delta Basin of Nigeria with the aim of exploring/identifying its geothermal potentials. A MATLAB program was used to perform regional-residual separation and spectral analysis on composite-eight (8) aeromagnetic maps. Specifically, statistical spectral analysis was used to determine Curie point depth and heat flow values within this area. Results showed that the centroid depth varies between 14.4194 km (within Okigwe – Aba sector) and the 6.7482 km (within Aba-Ahoada region) while the depth to Curie temperature isotherm varies between 7.4644 km and 24.8600 km below the mean sea level. It was also found that the Curie temperature isotherm within the basin is not a horizontal level surface but an undulating surface with geothermal gradients and heat flow ranging between 12.0676 and 40.1910 °C/Km and 25.3419 and 84.4010 mW/m2 respectively. Thus the calculated average geothermal gradient and heat flow for this area are 22.4886 °C/Km and 52.6012 mW/m2 respectively. Since the value obtained from this work is below 100 mW/m2 which is the minimum standard, it then means that this area may not potential be viable as a geothermal source.