Ultra-compact fiber optic sensor cable with superior crush resistance and operating temperatures down to -196°C. Available with 1 or 2 multimode fibers (MMF). It is a key technology for monitoring critical infrastructure such as LNG pipelines and tanks, oil and gas pipelines. For use in higher temperature ranges, all optical fibers based on Fused Silica can be optionally equipped with heat-resistant coating materials. This extends the potential field of application to a range from −190 °C to +385 °C. Distributed Fiber Optic Sensing (DFOS) allowed us to continuously gather flow profile information from a high-temperature high-rate gas well. The overall aim is to “Improve the accuracy of subsurface CO2 storage containment risk management to a level acceptable to both commercial and regulatory interests”.