DETECTION AND OBSERVATION OF DISTINCTIVE FEATURES OF DEPOSIT FORMATION USING OPTICAL FIBER Russian patent published in 2024 - IPC G01H9/00 G01V1/22 G01V1/42 G01V1/44 

FIELD: geophysics.

SUBSTANCE: invention can be used for downhole acoustic surveys in oil and gas industry. Disclosed is a subsurface deposit characterization system comprising sound source (110) deployed in first borehole (116), and fiber-optic distributed sensor (102) deployed in second borehole (118). Both boreholes extend from earth surface (122) into deposit formation (120). Optical fiber (102) is configured to respond along its length to incident sound waves (130), generated by sound source (110) and propagating through first borehole (116), through deposit formation (120) and through second borehole (118). System further includes optical source (104) for emitting optical pulses inside fiber-optic distributed sensor (102), while sound waves (130) are incident on fiber-optic distributed sensor (102). System also includes data collection system (103) connected to fiber-optic distributed sensor (102), to detect temporal changes in coherent Rayleigh noise (CRN) generated in fiber-optic distributed sensor (102) in response to optical pulses and incident sound waves (130); and computer system (140) configured to receive data from data collection system (104).

EFFECT: high accuracy and information content of the obtained data.

14 cl, 7 dwg