Feasibility investigation and design study of optical well logging methods for high temperature geothermal wells. Final report

The results are reported of a one-year program designed to investigate the feasibility of optical techniques applied to well-logging, to extend measurement capabilities in high-temperature geothermal boreholes. The basic concept is shown schematically. It makes use of a special armored cable containing fiber optic wave guides, connected to passive, downhole optical transducers. The latter modulate an optical carrier in response to borehole parameters. The optical carrier is a beam of infrared light transmitted from an optical source at the surface over an optical fiber. The modulated beam from the transducer is then returned to the surface over a second fiber, where conventional optical communications techniques are used to detect and decode the down hole information. (MHR)