Prediction of Water Saturation from Well Log Data using Deep Learning Algorithms

Abstract

This study develops a surrogate model to predict water saturation from well log data using neural-network-based deep learning algorithms. The model performance is evaluated by comparing the water saturation estimates obtained using deep learning algorithms and Archie’s law. The surrogate model evaluates the water saturation of a target reservoir using four well-log data types (density, porosity, resistivity, and gamma ray). Long Short-Term Memory (LSTM) is employed as the deep neural network algorithm, and its performance is compared with that of a multi-layer artificial neural network. Prediction via the LSTM based model showed outstanding results with the coefficient of determination above 0.7. Sensitivity analysis is conducted through sequence tuning, switching of well type, and k-fold cross-validation. The applicability of the model has been validated for the Volve oilfield in the North Sea and an offshore oilfield in Vietnam. PU - The Korean Society of Mineral and Energy Resources Engineers