|
|
Full Length Research
Paper
Geophysical mapping of the
occurrence of shallow oil sands in Idiopopo at Okitipupa
area, South-western Nigeria
R. K. Odunaike, J. A. Laoye, O. O. Fasunwon, G. C. Ijeoma and L. P. Akinyemi
Department of Physics, Olabisi Onabanjo University, Ago-Iwoye,
Ogun State, Nigeria.
*Corresponding author. E-mail:
kolaodunaike@yahoo.com.
Accepted
24 June, 2009 |
|
|
|
Oil sands are known to be an alternate source of energy and
of great economic value. To map the occurrence of shallow
oil sand deposits in Idiopopo, Okitipupa area in Ondo state
South-western Nigeria, vertical electric sounding (VES) in
11 stations along 3 profiles were carried out using the
Schlumberger configuration. Apparent resistivity value
obtained ranged from (135.7 ± 0.05)
ohm-m to
(4592.6 ± 0.05) ohm-m. The resistivity curves obtained for
each VES location were interpreted using partial
curve-matching and computer iterated techniques and it
revealed the presence of 4 and 5 geo-electric layers.
Interpretation of the geo-electric parameters obtained
indicates the possible presence of oil sand in the fourth
layer of VES 8 with a resistivity value of 164.9 ohm-m at a
depth of about (16.50 ± 0.05) m and thickness of (39.03 ±
0.05) m. Also, VES locations 5 to 8 (profile one) all
indicate the possible presence of oil sands in the fifth
layers with a resistivity value of less than (725.0 ± 0.05)
ohm-m at a mean depth of (39.05 ± 0.05) m. However, due to
the depth of probe more information about these layers could
not be ascertained. It is recommended that further
geophysical survey techniques like VES with increased
electrode spacing and/or 2D resistivity method should be
employed to effectively map the oil sands especially along
profile one.
Key words:
Geo-electric, oil sand, Idiopopo, South-western Nigeria,
vertical electric sounding, resistivity.
|
|
