Available with temperature ratings up to 300 degC [572 degF], WellWatcher BriteBlue HT high-temperature multimode DTS fiber has been used extensively for monitoring production and injection wells in heavy oil thermal recovery operations in various parts of the world. For example, it is used in SAGD injector wells to monitor the steam temperature and in the producer wells to ensure that the correct level of subcooling is maintained to avoid steam breakthrough from the injector above.