Project Title: Large-Bore High-Pressure Precision Managed Pressure Drilling Equipment and Large-Scale Application

Participating Enterprises: Drilling & Production Engineering Technology Research Institute, CNPC Chuanqing Drilling Engineering Co., Ltd.

Award Received: Scientific and Technological Progress Award

Project Number: ECF-2026-SYE-1008

Main Participants: Zuo Xing, Tang Gui, Li Sai, Chen Ze, Xiao Jie, Chen Zhaoxi, Zhang Dongmei, Li Xin, Duan Hongzhi, Hu Biwen, Xu Yonghong, Ou Wenting, Huang Yalou, Jiang Lin, Lu Siyu

Expert Review Comments:

This achievement extends precision managed-pressure drilling to large-hole, high-flow operations, overcoming bore-size and circulation-capacity constraints in conventional equipment. A large-bore rotating control system, a 130-mm choke passage and dynamic pressure correction support flow rates up to 120 L/s across drilling, connections and tripping. Deployment in 250 well operations demonstrates the engineering maturity of the integrated package. Its value lies in maintaining bottomhole-pressure stability while supporting operational continuity and reducing kick/loss complications in large-hole sections. The solution is particularly relevant to deep and ultra-deep wells crossing multiple pressure regimes or formations with narrow operating windows.

Main Innovations:

A wellbore pressure prediction and dynamic correction model for large-bore wells was developed. The pressure calculation accuracy reached 95%. An automatic closed-loop controlled large-bore rotating control device and a large-bore automated choke control system were developed. The choke system bore was increased to 130 mm, and the applicable flow rate was increased to 120 L/s. A precision managed pressure drilling process for multiple operating conditions was established. Precise bottomhole pressure control, rapid kick and loss identification, and safe tripping operations were achieved for large-bore wells. The technology fills the technical gap in precision managed pressure drilling for large-bore wells.

Main Uses and Technical Principles:

The technology is mainly used for precise pressure control in large-bore sections of deep, ultra-deep, and unconventional oil and gas wells. It is suitable for multiple pressure systems, alternating high-and low-pressure formations, narrow drilling windows, and formations with frequent kicks and losses. Wellbore pressure is predicted and corrected with real-time data. A large-bore rotating control device and an automated choke control system are used to regulate surface backpressure. Bottomhole pressure is maintained within the safe drilling window. Kicks and losses are identified from inlet and outlet flow rates, standpipe pressure, and casing pressure. Automatic pressure compensation, formation gas drainage and pressure reduction, and continuous annular fluid-level monitoring are also applied. These functions enable safe managed pressure drilling under multiple operating conditions.