FIBEROPTIC SYSTEMS AND METHODS FOR SUBSURFACE EM FIELD MONITORING

• Main Authors: DONDERICI, BURKAY, SAN MARTIN, LUIS E, SAMSON, ETIENNE M
• Format: Patent
• Language: English
• Published: 07.12.2019
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

A disclosed subsurface electromagnetic field monitoring system employs at least one fiberoptic cable (106) to optically communicate measurements from an array of electromagnetic field sensors (114) in a borehole (102). 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 (104) that serves as an electrode (122) for injecting a distributed current (202, 222) 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.