This paper proposes a reflective fiber-optic sensor network for multiparameter state monitoring in oil and gas wells. The network is composed of a ground-based sensing signal demodulation system, a fault detection module, and an underground optical fiber sensing topology. Permanent downhole fiber-optic cables are critical infrastructure in wellbore monitoring systems, ensuring reliable transmission of data for applications such as distributed temperature, acoustic, and strain sensing (DTS, DAS, and DSS)—all with one 1/4-in control line. Unlike traditional single-point measurements that rely on discrete sensors measuring the data at. Paper presented at the SPE/ICoTA Well Intervention Conference and Exhibition, The Woodlands, Texas, USA, March 2020. The technology addressed in this course originated for oil and gas operations but are applicable for subsurface CCUS, geothermal. Suitable for oil wells, gas wells, coal mines or under high temperature conditions. 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. Chemistry searches match terms (trade names, IUPAC names, etc. ) Substructure (use SSS=) and similarity (use.