Shallow resistivity measurement for cathodic protection of pipelines in the Niger Delta

The variation in the geo-electric resistivity of the superficial soils across the Niger Delta was investigated by running profiles spanning over 350 km and covering all the geomorphic zones of the Niger Delta, using a Schlumberger electrode configuration. The results indicate characteristic resistivity ranges. The spatial variation in resistivity was explained by differences in topographic elevation, depth to water table, soil type, and water quality. Based on the soil resistivities in the various geomorphic zones, the corrosivity of the soils were determined and methods of cathodic protection prescribed. A north–south traverse will generally experience a decreasing soil resistivity that is truncated at the beach ridges.