Water saturation
assessment is recognized as one of the most critical
aspects of formation evaluation, reserve estimation, and prediction
of the production performance of any hydrocarbon reservoir. Water
saturation measurement in a core laboratory is a time-consuming and
expensive task. Many scientists have attempted to estimate water saturation
accurately using well-logging data, which provides a continuous record
without information loss. As a result, numerous models have been developed
to relate reservoir characteristics with water saturation. By expanding
the use and advancement of soft computing approaches in engineering
challenges, petroleum engineers applied them to estimate the petrophysical
parameters of the reservoir. In this paper, two techniques are developed
to estimate the water saturation in terms of porosity, permeability,
and formation resistivity index through the use of 383 data sets obtained
from carbonate core samples. These techniques are the nonlinear multiple
regression (NLMR) technique and the artificial neural network (ANN)
technique. The proposed ANN model achieved outstanding performance
and better accuracy for calculating the water saturation than the
empirical correlation using NLMR and Archie equation with a high coefficient
of determination (R
2) of 0.99, a low average
relative error of 1.92, a low average absolute relative error of 13.62,
and a low root mean square error of 0.066. To the best of our knowledge,
the current research establishes a novel foundation using the ANN
model in the estimation of water saturation.