Prediction of Compressional Wave Velocity and Formation Bulk Density from Electrical Resistivity in the Sub-surface of South-East and South-South Nigeria
U. K. Afegbua *
Centre for Geodesy and Geodynamics, Toro, Bauchi State, Nigeria
F. O. Ezomo
Department of Physics, University of Benin, Benin City, Edo State, Nigeria
O. D. Osahon
Department of Physics, University of Benin, Benin City, Edo State, Nigeria
J. Braimoh
Department of Science Laboratory Technology, Auchi Polytechnic, Auchi, Edo State, Nigeria
M. S. Tsalha
Centre for Geodesy and Geodynamics, Toro, Bauchi State, Nigeria
H. T. Sanni
Centre for Geodesy and Geodynamics, Toro, Bauchi State, Nigeria
D. Duncan
Centre for Geodesy and Geodynamics, Toro, Bauchi State, Nigeria
E. S. Usifoh
Centre for Geodesy and Geodynamics, Toro, Bauchi State, Nigeria
O. S. Abimaje
Centre for Geodesy and Geodynamics, Toro, Bauchi State, Nigeria
A. O. Biose
Energy Commission of Nigeria, Energy Centre, University of Benin, Benin City, Edo State, Nigeria
*Author to whom correspondence should be addressed.
Abstract
The aim of this study is essentially to predict compressional wave velocity (Vp) from electrical resistivity (R) observations in parts of the South-South and South-East Nigeria; and also to compute the formation density (p) of consolidated layers in the subsurface and subsequently establish a relationship between p and Vp for the entire region covered. The known formation and observed resistivity from field surveys formed the baseline data for this study. The methodology involved the collection of known and observed values of electrical resistivity in the study area. Using relevant empirical equations as initial models, the Vp and p were computed and a relationship between Vp and R was established using regression analysis. The predicted Vp and the corresponding p were correlated with results obtained from earlier studies in the area. The model linking the density (p) and compressional velocity (Vp) developed in this study would be useful for future Vp prediction and density computation in the South-South and South-East regions given resistivity values of interest. Findings from this research would also be useful for the estimation of some petrophysical parameters especially in the South-South region.
Keywords: Electrical resistivity, P-wave velocity, formation density, South-East and South-South Nigeria, petrophysical parameters