Delineation of Prospective Hydrocarbon Zones in Parts of the Central Benue Trough, Nigeria, Using High-Resolution Aeromagnetic Data

Abstract

Aeromagnetic data from parts of the Central Benue Trough were interpreted to determine sedimentary thickness and temperature at depth across the study area, with implications for hydrocarbon accumulations. Three depth estimation methods (Source parameter imaging (SPI), Standard Euler deconvolution, and Spectral analysis) were used, and the results were compared. The Source parameter imaging (SPI) ranged from -119.23 to -6045.08 m, and Standard Euler deconvolution for the structural index (SI) of 3 ranged from 608.67 to -4741.70 m. Spectral depth analysis revealed depths of deep and shallow magnetic sources, with deep sources ranging from 1.03 to 5.09 km and an average depth of 3.15 km, while shallow magnetic sources ranged from 0.21 to 1.84 km and had an average depth of 0.6 km. The temperature at depth over the study area was calculated and the results revealed temperature values ranging from 79.9 to 387.42 °C, with an average value of 154.61 °C. The southwestern, northern, northeastern and central parts were delineated as potential hydrocarbon targets areas due to appropriate sedimentary thickness and temperature. These areas corresponds to Otobi, Otukpo, Taraku, Nov, Moi Igbo, Igbor, Aliade, Ndeel, Ito, Wannune, Obi, Giringwe, Azare, and Wuse due to appropriate sedimentary thickness and temperature. Furthermore, clusters of structures, as revealed by the total horizontal gradient and first vertical derivative maps, trend predominantly NE-SW, with a cross-cutting NW-SE structure, suggesting a favourable structural system that may enable migration and entrapment of hydrocarbons within the area.