ASSESSMENT OF GEOTHERMAL POTENTIAL IN PARTS OF NIGER DELTA, NIGERIA, USING HIGH RESOLUTION AEROMAGNETIC DATA

Abstract

Geothermal potential in parts of Niger Delta region corresponding to Warri, Kwale, Burutu and Patari was assessed using spectral analysis of aeromagnetic data. The study area covers a total area of 12,100 km2 and it is bounded by latitudes 5°00ʹ and 6°00ʹN and longitudes 5°30ʹ and 6°30ʹE. The total magnetic data of the area was subjected to spectral analysis using Matlab, Oasis Montaj and Surfer 13 software’s. Regional/residual separation was applied on total magnetic intensity map and thereafter the residual map was divided into 16 overlapping blocks. Spectral analysis was done on the overlapping blocks and showed variations of high and low magnetic signatures. The Centroid depth and depth to top boundary were obtained from the plot of log of power spectrum against wavenumber. These two parameters were used to determine the Curie point depth (CPD). The Curie point depth obtained was then used to determine the geothermal gradient and the heat flow over the study area. The result of the study shows that the deepest depth of sedimentary thickness was found in the central region and ranges between 11 km and 13 km. From the same central region corresponding to Uvwie, Udu, north of Ughelli and Isoko, shallow Curie point depth vary between 16 km and 30 km. The corresponding geothermal gradient and the heat flow values varying from 19 to 36 o C/km and 28.00 to 88.00 mW/m2 respectively. Therefore, harnessing geothermal potential in this area is probable within the central region and would be an added advantage to power generation in Nigeria.