DETERMINATION OF THE SAFETY OF BURIED PIPELINES IN OLOGBO, EDO STATE USING SCHLUMBERGER ELECTRICAL RESISTIVITY METHOD

Electrical surveys are usually employed to determine the subsurface resistivity distribution by making measurements on the ground surface. From these measurements, the true resistivity of the subsurface can be estimated. The ground resistivity is related to various geological parameters such as the mineral and fluid content, porosity and degree of water saturation in the rock. In this article, Electrical resistivity measurement was carried out at the ELPS CS1site at Ologbo Edo State. The tests were conducted at six points on the project site based on the predetermined AB/2 spacing and Mn/2 spacing for Schlumberger method. The K factor was used to convert the resistance in Ω measured in the field to apparent resistivity in Ωm. The resulting apparent resistivity was subjected to an inversion process that turned the apparent resistivity to the true resistivity of the subsurface. The 1D resistivity models shows values are within the range of 55.2 Ωm to 9805 Ωm, within an investigated depths of 10 m while the 3D electrical resistivity contour for both the surface and 5 m depth, depicts the distribution of electrical resistivity within the investigated site. It shows area of low and high electrical resistivity values. 1D and 3D electrical resistivity models, gave a clear indication that majority of the determined electrical resistivity values from the surface, down to a depth of 5 m, are greater than5 Ωm.