Review of Research Advances in Full-Spectrum Fiber Optic Sensing Technologies for CO₂ Geological Storage

Fiber optic sensing technologies, owing to their intrinsic safety, immunity to electromagnetic interference, and distributed sensing capabilities, demonstrate unique applications in monitoring CO₂ geological storage. However, existing review studies often focus on a single sensor type or specific monitoring scenarios, lacking a systematic classification and scenario adaptation analysis of full-spectrum technologies from point and quasi-distributed to fully distributed sensing. To address this research gap, this paper systematically reviews the principles and performance characteristics of full-spectrum fiber optic sensing technologies, covering core mechanisms of distributed temperature, acoustic, and strain sensing, and establishes a technology-adaptation framework for typical monitoring scenarios including wellbore integrity, reservoir dynamics, caprock faults, and near-surface facilities while integrating the latest advances in machine learning and deep learning for fiber optic data processing. Based on systematic analysis, prioritized short-term and long-term recommendations are proposed, covering multitechnology integration, extreme-environment adaptability, intelligent data processing, and standardization. This work aims to provide theoretical support for the design of monitoring schemes in CCUS projects and to promote the large-scale application of fiber optic sensing technologies in carbon sequestration safety monitoring.