This article is protected by copyright. All rights reserved 1 Article Hybrid Intelligent Modelling of the Viscoelastic Moduli of Coal Fly Ash Based Polymer Gel System for Water Shutoff Treatment in Oil and Gas Wells † Ahmad A. Adewunmi, 1,2 Suzylawati Ismail, 1,* Taoreed O. Owolabi, 3 Abdullah S. Sultan, 4 Sunday O. Olatunji, 5 Zulkifli Ahmad 6 1 School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang, Malaysia. 2 Center for Integrative Petroleum Research, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia. 3 Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia 4 College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia. 5 Computer Science Department, University of Dammam, Dammam, Kingdom of Saudi Arabia. 6 School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang, Malaysia. *Corresponding author email: chsuzy@usm.my † This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: [10.1002/cjce.23436] Received 7 June 2018; Revised 11 October 2018; Accepted 12 October 2018 The Canadian Journal of Chemical Engineering This article is protected by copyright. All rights reserved DOI 10.1002/cjce.23436