This paper reviews the sensing principle, structural design, and temperature measurement performance of fiber-optic high-temperature sensors, as well as recent significant progress in the transition of sensing solutions from glass to crystal fiber. Due to the influence of reservoir geological features and cementing quality, wellbore leakage and damage often occur. The traditional packer pressure test has many problems, such as complicated production process, long production period and low accuracy of leakage location, which have seriously. DTS allows the inference of an optical fiber's temperature at decimeter to meter resolution, depending on the design of the interrogator. The cables marked with Dry; They are a series of cables in which the typical water blocking the intermediate tubes (gelatin, water swelling tape or powder) is replaced with a solid foamed thermoplastic elastomer. Distributed fiber optic vibration signal logging is a technology that uses fiber optics to sense the vibration signals returned from different formations or well walls to analyze the surrounding formation characteristics or downhole events, which has the advantages of strong real-time monitoring. Paper presented at the SPE Offshore Europe Conference & Exhibition, Aberdeen, Scotland, UK, September 2023. Distributed Fiber Optic Sensing (DFOS) allowed us to continuously gather flow profile information from a high-temperature high-rate gas well. The objective of this case study is to. le length.