Project Title: Key Technologies and Applications of Integrated Control for Wellbore Flow Safety in Drilling in Deep Complex Formations

Participating Enterprises: China University of Petroleum (East China)
China National Petroleum Corporation Engineering Technology Research Institute Co., Ltd.
International Drilling Company, GWDC

Award Received: Technological Invention Award

Project Number: ECF-2026-SYE-1009

Main Participants: Wang Jintang, Liao Bo, Wang Jianlong, Sun Jinsheng, Sun Xiaohui, Zhang Jianbo, Wang Ren, Lv Kaihe, Wang Qibing

Expert Review Comments:

A major strength of this achievement is its coordinated treatment of pressure prediction, formation integrity and kick/loss control. Multicomponent phase-change physics and physics-informed neural networks are combined with mechanical–chemical wellbore strengthening and dual-choke control, connecting prediction and early warning with operational response. Field validation shows pressure-prediction errors within 5%, and the technology has supported major projects including the Shendi Take-1 well. The overall technology is internationally advanced, with quantitative pressure prediction and wellbore strengthening internationally leading. Its originality and field experience make it a valuable integrated solution for high-pressure, high-temperature drilling within narrow operating windows.

Main Innovations:

To address the challenges of drilling in deep complex formations, a high-temperature and high-pressure acidic gas dissolution–exsolution analytical model and a PINN-based real-time pressure calculation method were developed, revealing phase transition anomalies and the hidden mechanisms of gas influx, and reducing prediction errors from over 13% to within 5%. Elastic plugging, microgel wall-strengthening, rheology regulation, and dual-throttle collaborative pressure stabilization technologies were developed to establish a lost-circulation control drilling fluid system for complex formations, increasing pressure-bearing capacity by 51.8% and reducing pressure fluctuations by 58%. A pattern-recognition-based diagnosis method and an integrated well-killing and plugging technology were developed, enabling kick/loss identification 10 min earlier and increasing the one-time well-killing success rate to 96%.

Main Uses and Technical Principles:

To address the challenges of inaccurate wellbore pressure prediction, narrow pressure windows prone to lost circulation, and difficult identification of complex kicks and losses during deep oil and gas drilling, an integrated technology system for precise pressure control and well-control assurance in deep complex formations has been developed. High-temperature and high-pressure experiments were conducted to reveal the phase transition and dissolution-exsolution mechanisms of acidic gases, establishing a multicomponent multiphase flow model and enabling real-time wellbore pressure prediction using physics-informed neural networks. Adaptive plugging agents, wall-strengthening agents, and dual-throttle pressure stabilization equipment were developed to enhance wellbore stability and expand the safe pressure window. By integrating multi-source monitoring data with intelligent diagnostic algorithms, accurate kick/loss identification, early warning, and integrated well-killing and plugging control were achieved. This technology improves the safety and efficiency of deep complex oil and gas resource development.