DOWNHOLE SPECIES SELECTIVE OPTICAL FIBER SENSOR SYSTEMS AND METHODS

摘要

A disclosed downhole optical sensor system includes at least one optical sensor (40) positioned in a borehole and coupled to an interface via a fiber optic cable (44). Each of the optical sensors (40) includes a waveguide (82) for conducting light, and a reagent region (88) positioned between the waveguide (82) and a fluid in the borehole to absorb a portion of the light from the waveguide (82), the portion being dependent upon a concentration of a chemical species in the fluid. A described method for operating a well includes deploying one or more downhole optical sensors in a fluid flow path in the well, probing the one or more downhole optical sensors (40) from a surface interface to detect concentrations of one or more chemical species, and deriving a rate of scale buildup or corrosion based at least in part on the detected concentrations.