Patent ID: 8347958

Claim:
A method for monitoring fluid flows in a wellbore, a reservoir or a pipeline, comprising: transmitting a monitoring signal through a fiber optic cable, wherein the monitoring signal comprises a pulse of a coherent beam of electromagnetic radiation where a coherence time of the coherent beam of electromagnetic radiation is equal to or longer than a time duration of the pulse, and wherein the fiber optic cable is disposed along or is disposed appurtenant to at least a section of the wellbore, the reservoir or the pipeline; detecting coherent Rayleigh noise generated by the transmission of the coherent beam of radiation through the fiber optic; processing the detected coherent Rayleigh noise to identify one or more acoustic occurrences in the section of the wellbore, the reservoir or the pipeline; and determining one or more properties of a fluid flowing in the section of the wellbore, the reservoir or the pipeline from the identified acoustic occurrences.