Carbon capture, utilization, and storage (CCUS) is a core technology for achieving carbon neutrality. The safety of geological carbon storage is crucial for its large-scale application, and the response characteristics of surface water environments to CO2 leakage directly determine the effectiveness of safety early warning systems. This study, conducted in the CCUS demonstration area of Shengli Oilfield, employs a combination of laboratory simulation experiments and in situ field monitoring campaigns to systematically clarify the dynamic response patterns of multiple surface water environmental indicators under different leakage scenarios. Sensitive indicators are identified, and hierarchical early warning thresholds are established. Results indicate that CO2 concentration and pH exhibit the most stable and sensitive responses to leakage, making them ideal core discriminant indicators. Electrical conductivity and total dissolved solids exhibit significant increases during leakage events, making them suitable as auxiliary verification indicators. By comparison, the response characteristics of phosphate ions, chemical oxygen demand, and certain metal ions demonstrate strong environmental dependence. Additionally, a surface water monitoring system covering the "core-auxiliary-reference" three-level indicator framework was established. A critical threshold of CO2 concentration >1000 ppm and pH < 6 was proposed to diagnose leakage. This study provides a systematic theoretical basis and technical support for the safety assessment and risk early warning of surface water environments in CCUS project areas.
Zhen et al. (Tue,) studied this question.