Hydrocarbon potential evaluation of Middle Benue Basin, East Central Nigeria using high resolution aeromagnetic data

Abstract

Relatively cheap and non-intrusive magnetic geophysical technique has been employed to reduce the hydrocarbon exploration uncertainty in the Middle Benue Basin which straddles the northeastern and southeastern parts of Nigeria. Various derivatives and magnetic attributes extracted from the filtered, transformed and enhanced aeromagnetic data of the basin highlighted valuable information employed to appraise the hydrocarbon generating and preservation potentials of the basin, thus delineating the prospective regions where further search light of expensive and intrusive geophysical exploration tools could be focused. The trough delineated from the analyzed aeromagnetic data comprised of a massive 350 km NE-SW trending fan shaped sedimentary body bounded to the northwest and southeast by Basement Complex rocks. Active structural framework with dominant NE-SW fault systems which appeared to be the landward extension of the Chain and Charcot offshore fractures characterize the basement rocks that underlay the sediments. Sedimentary thickness of up to 3.68 km in some parts of the basin obtained from depth weighting analyses, indicate the possibility of hydrocarbon generation through the maturation of organic matter from available source rock(s). Analytic signal grids confirmed the occurrence of already documented volcanic intrusions in addition to newly delineated ones. These volcanics which are often renowned for compromising the hydrocarbon potential of a sedimentary basin are widespread in the western and southern parts the basin. Combination of adequately thick sedimentary units which overly structurally active basement rocks in regions of limited (very few/non) occurrence of volcanic intrusions delineate the north central region for further petroleum exploration prospect evaluation.