Project Title: Digital Monitoring Instrument and Early Warning System for Drilling Overflow and Leakage

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

Award Received: Technological Invention Award

Project Number: ECF-2026-SYE-1007

Main Participants: He Xianjie, Li Zhilin, Duan Mubai, Wei Qiang, Xue Qiulai, Qian Haodong, Li Zhongquan, Feng Yinxiang, Shen Minghua, Jin Liang

Expert Review Comments:

Reliable detection of weak signals is fundamental to effective kick and loss warning. This project advances continuous electromagnetic liquid-level measurement and quantitative outlet-flow measurement in partially filled pipes, linking downhole, wellbore and surface information through tiered warnings. Across 162 wells, warnings preceded existing methods by 3–9 minutes, with 94.7% accuracy, providing additional time for operational response. The technology is internationally advanced overall, with partially filled outlet-pipe flow measurement internationally leading. Its practical contribution is earlier recognition of well-control risks, particularly during lost returns and changing kick/loss conditions, making it relevant to both complex-well operations and digital wellsite development.

Main Innovations:

It pioneered downhole kick & loss risk identification tech, predicting kick signs via temperature-pressure variations and enabling timely data transmission. An electromagnetic continuous wellbore liquid level monitoring method with 8s step accurately detects lost returns and loss-to-kick transitions, solving real-time continuous monitoring challenges. A precise inlet-outlet microflow monitoring method upgrades flow detection from qualitative to quantitative. A three-tier early warning method covering bottomhole-wellbore-surface forms triple protection, securing a critical 3-minute response window.

Main Uses and Technical Principles:

Primary Purpose: This system is designed for the precise monitoring and early warning of overflow and leakage throughout the entire drilling process to ensure well control safety; The system consists of six pieces of equipment—a downhole overflow while-drilling measurement tool, a leak-zone monitoring tool while-drilling, an electromagnetic wellbore liquid level monitoring device, an automatic grouting and overflow & leakage early warning device of tripping, an inlet and outlet micro-flow monitoring device, and an electronic liquid level monitoring device—along with a set of intelligent warning software for drilling overflow and leakage, forming a comprehensive “downhole-wellbore-surface” overflow and leakage early warning system and digital technology. Technical Principle: Downhole overflow and leakage risk warning is realized based on downhole temperature-pressure and annulus flow rate monitoring. Wellbore overflow and leakage risk identification is achieved by combining continuous wellbore liquid-level measurement and accurate kick-loss monitoring during tripping. Accurate surface overflow and leakage alarming is implemented through precise inlet-outlet micro-flow monitoring and accurate measurement of circulating tank liquid level.