Pioneering Well Logging: The Role of Fiber Optics in Modern Monitoring for Well Integrity Diagnosis

Maintaining well integrity is a critical aspect of safe, efficient, and economically viable oil and gas production. Traditional well diagnostic tools such as calipers and single-point acoustic and temperature logging have been used extensively to assess well conditions. However, these approaches often fall short when confronted with complex, intermittent, or distributed anomalies due to their inherent spatial and temporal limitations. These limitations can lead to ambiguous or inconclusive assessments, wasting valuable time and remediation costs. This study presents a comparative analysis between these conventional approaches and the latest distributed fiber-optic sensing (DFOS) technologies. Specifically, we highlight the diagnostic power of distributed temperature sensing (DTS) and distributed acoustic sensing (DAS) in two real-world field applications. In each case, traditional tools failed to isolate the source of tubing-to-annulus communication with precision. Fiber optics, on the other hand, provided comprehensive, real-time insights and enabled accurate localization of the anomalies within a fraction of the time (Johannessen et al., 2012; Silixa, 2022). The integration of fiber-optic sensing not only delivered superior diagnostic clarity but also reduced the diagnostic timeline by over 85%. These results demonstrate that fiber optics represents a paradigm shift in well integrity assessment, transitioning from interpretive and reactive methodologies to real-time, high-resolution, and proactive diagnostics.