ROCK PROPERTIES FOR LITHO-FLUID DISCRIMINATION IN LOWER AGBADA RESERVOIR SAND NIGER DELTA, NIGERIA

Abstract

The exploration and exploitation of hydrocarbons are usually associated with many risks, particularly the potential drilling location in order to mitigate these risks, it is important to describe a reservoir in terms of its lithology and pore fluid content. A quantitative rock physics analysis has been carried out to remove the uncertainties that usually accompany the conventional approaches in determining lithology and discriminating pore fluids using well logs. Density, compressional wave velocity and shear wave velocity were used as inputs and applied in an integrated approach to identify and delineate hydrocarbon charged reservoirs in” Tolujobi” field, offshore, Niger Delta. Shear wave velocities were derived empirically using the Castagna’s mud rock line relationship. Cross plotting of the rock properties were used to discriminate lithology and pore fluids which responded in different ways by showing visible separation and identifiable cluster trends from the background trends. The crossplot also discriminated the fluids into gas and brine. This study has been able to discriminate hydrocarbon reservoirs using well logs in the field of study from which gas sands, brine sands and shales were successfully characterized.