Vol. 21 No. 3 (2026): September

Cover image by Mei-Chun Li on pages 247-268. The cover illustrates an integrated wellbore thermal-management strategy for deep and ultra-deep drilling. Four interconnected components, including temperature modelling and prediction, functional thermal-management materials, cooling technologies and equipment, and real-time temperature monitoring and updating, form a coordinated framework for wellbore temperature regulation. These components work together to regulate wellbore temperature, highlighting the potential of integrated thermal management to improve drilling fluid efficiency and ensure reliable performance under extreme downhole conditions.