Modeling Magnetic Basement in Relationship to Hydrocarbon Habitats in the Central Niger Delta, Nigeria
D. A. Obi *
Department of Geology, University of Calabar, Nigeria
A. J. Ilozobhie
Department of Physics, University of Calabar, Nigeria
S. E. Lebo
Department of Geology, University of Calabar, Nigeria
Evidence Zoogbara
Shell Exploration Company Ltd., Nigeria
*Author to whom correspondence should be addressed.
Abstract
Aeromagnetics has over the years been used as a reconnaissance tool for hydrocarbon exploration. Modeling of source of magnetic anomalies can also reveal basin depth and configuration of supposed hydrocarbon habitats. This study was done using (8) aeromagnetic maps on a scale of 1:100,000 covering the central Niger Delta states in Nigeria. The data was digitized and processed using the United States Geological Survey potential field software’s version 2.2 for map merging, reduction to pole, polynomial filtering, horizontal gradient magnitude (HGM), Wenner deconvolution, forward and inverse modeling (pdep and saki programs). The result indicates areas around Benin River, Warri, Kwale and Aboh with more dominant shallow depths (0.8 km-2.01 km) with minor areas reaching deeper sources (2.5 km-4.5 km) while areas around Forcados, Burutu and Ahoada have predominantly deeper sources (2.5 km-4.5 km). Generally, there is an agreement in all the depth-derived sources of an increase in sediment thickness accumulation from the onshore (Warri areas) towards the offshore (Burutu) with horst and graben structures as indicated from the saki models. The identified grabens are the recognized possible hydrocarbon habitat, which forms potential targets for hydrocarbon exploration prior to seismic exploration.
Keywords: Hdrocarbon, modeling, habitats, polynomial filtering, Wenner deconvolution, horst, graben