Oil Sands Exploration in Ijebu-Imushin using Magnetic and Electrical Resistivity Methods

There has been tremendous interest in the exploration and production activities of readily available alternatives to conventional oil. Oil seeps observed in Ijebu-Imushin, Ogun State, south-western Nigeria, served as an indication of the occurrence of oil sands – a non-conventional hydrocarbon resource – in the area. Electrical and ground magnetic geophysical survey techniques were thus employed to map the occurrence of the oil sand deposits in the study area as well as to determine the depth to the basement in order to obtain information on the subsurface for exploitation activities. Three vertical electrical soundings and 2-D electrical imaging along a single profile were carried out using the Schlumberger and Werner configurations, respectively. Modelling the likely subsurface structures from the measured magnetic profiles indicates a likely maximum depth to basement of 300m across the study area. The constructed strata from the electrical methods revealed that oil sands deposit are likely to be present and substantial in the south-western part of the study area. The deposit appears to commence from a depth of about 2 m, extending to a depth of approximately 40 m in this part of the study area.