Interpretation of Aeromagnetic Data for Petroleum Reconnaissance Exploration Over the Eastern Part of the Nigerian Sector of the Chad Basin, Northeastern Nigeria

Abstract

This study was conducted to assess the petroleum potential of the eastern part of the Nigerian sector of the Chad Basin using high-resolution aeromagnetic data. The study area, situated within a Cretaceous-Tertiary intracratonic basin, forms part of the Central and West African Rift System (CWARS). The utilized data was obtained for the Nigerian Geological Survey Agency (NGSA) by Fugro Airborne Geophysical Surveys using a flight line spacing of 500 m and a tie line spacing of 5000 m, respectively, and a sensor mean terrain clearance of 80 m, with three Scintrex CS3 Caesium Vapour magnetometers. The data were subjected to a series of transformations including reduction to the equator, regional-residual field separation, analytic signal computation, and 3D Euler Deconvolution for depth-to-basement estimation. The results have identified three major sub-basins and irregular basement topography. The sub-basins are located in the western, central and northeastern parts of the study area. The prominent among the sub-basins, located in the western part of the area reaches a thickness of up to 5 km while the other two located at the central and eastern parts attain depths of up to 4 km in places. These sedimentary thicknesses fall within the critical range for the thermal maturation of organic matter, indicating a high potential for hydrocarbon generation and accumulation. The results provide valuable insight for early-stage petroleum reconnaissance and regional geological understanding of the Chad Basin.