Neural network architecture optimization using automated machine learning for borehole resistivity measurements

• Published in: Geophysical journal international Vol. 234; no. 3; pp. 2487 - 2500
• Main Authors: Shahriari, M, Pardo, D, Kargaran, S, Teijeiro, T
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01.09.2023
• Subjects: Neural networks, fuzzy logic; Wave propagation; Downhole method; Inverse theory; Machine learning
• ISSN: 0956-540X; 1365-246X
• DOI: 10.1093/gji/ggad249

SUMMARY Deep neural networks (DNNs) offer a real-time solution for the inversion of borehole resistivity measurements to approximate forward and inverse operators. Using extremely large DNNs to approximate the operators is possible, but it demands considerable training time. Moreover, evaluating the network after training also requires a significant amount of memory and processing power. In addition, we may overfit the model. In this work, we propose a scoring function that accounts for the accuracy and size of the DNNs compared to a reference DNNs that provides good approximations for the operators. Using this scoring function, we use DNN architecture search algorithms to obtain a quasi-optimal DNN smaller than the reference network; hence, it requires less computational effort during training and evaluation. The quasi-optimal DNN delivers comparable accuracy to the original large DNN.