The application of integrated geophysical methods in oil san | 16625
International Research Journals

The application of integrated geophysical methods in oil sand exploration in Agbabu area of Southwestern Nigeria


J. O. Amigun1, A. O. Adelusi and B. D. Ako

In this study, the occurrence and structural settings of the Agbabu tar sand deposit have been investigated because of the economic importance of bitumen as a readily available alternative source of energy. This investigation was carried out by employing integrated geophysical methods of magnetic and electrical resistivity (VES and dipole – dipole). Ten vertical electrical sounding (VES) points using Schlumberger array with maximum half way spread length (AB/2) of 225m, dipole - dipole with potential spacing of 50m and sixty three magnetic stations at 20m station interval were occupied along three established traverses across the study area. The resistivity curves obtained revealed up to a maximum of five geoelectric layers and the inversion of the geoelectric parameters of both the VES and 2D electrical resistivity (tomography) indicate the possible presence of oil sand in the fourth layer with relatively high apparent resistivity value ranging between 385 to 13,012 Ohm-m at a mean depth of 50m. This result was corroborated by boreholes drilled in the area. The interpretation of forward modeling of the ground magnetic shows the presence of thin dyke and fault, the nature of the basement topography and the indication that the tar sand in the study area is characterized by good lateral continuity. The results of this study have offered important geologic information that will aid the mine design and economic exploitation of the Agbabu tar sand deposit.

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