Fiberoptic Systems and Methods for Subsurface EM Field Monitoring

Abstract

A disclosed subsurface electromagnetic field monitoring system employs at least one fiberoptic cable to optically communicate measurements from an array of electromagnetic field sensors in a borehole. A data processing system that receives the measurements and responsively models the subsurface electromagnetic field, which in at least some cases is generated by a controlled source such as a downhole electric or magnetic dipole source or a casing that serves as an electrode for injecting a distributed current into the formation. At least some disclosed method embodiments include: receiving measurements from an array of electromagnetic field sensors via a fiberoptic cable in a borehole; modeling a subsurface electromagnetic field based on estimated formation parameters to predict said measurements; adjusting the estimated formation parameters to improve a match between predicted measurements and received measurements; and displaying the estimated formation parameters after matching the predicted measurements to the received measurements.

Dependencies are inferred from the claim text.