Sedimentary thickness and basement depths of eastern Niger delta, Nigeria, from aeromagnetic data and implications for hydrocarbon prospects

Abstract

A knowledge of sedimentary thickness and basement depths of a basin is necessary in understanding the structural set up of formations and evaluation of the hydrocarbon potentials of a region. In this work aeromagnetic data, obtained from the Nigerian Geological Survey Agency (NGSA) Abuja, has been interpreted to obtain sedimentary thickness, structural faults and intrusions including the basement depths of the eastern Niger Delta, Nigeria with the implications for hydrocarbon prospecting. Results from magnetic attribute analysis, total horizontal derivative operations, spectral analysis and source parameter imaging reveal the following: the study area is magnetically heterogeneous; the magnetic intensities range for the region is from – 46.2 nT to 160.3 nT, with residual magnetic intensity values of -15 nT to 13 nT revealing sediments with low magnetic rocks in the southwestern and southeastern parts of the study area and magnetic rocks and basement intrusions in the northwestern, northeastern and central parts of the study area; sedimentary thickness range from 96.5 m to 6601.5 m hosting faulted anticline and syncline structural bodies good enough for hydrocarbon formation and trapping and a maximum depth to basement of 6601.5 m. The sedimentary thickness and structural types, influenced by the basement intrusions, make the region a hydrocarbon potential area and it is recommended that prospecting in the southern and northern parts of the study area should be intensified.