Patent ID: 7946341
Filing Date: 2011-05-24
Classification: E21B,G01V,Y02C

Abstract:
1. A method for monitoring a wellbore, a reservoir or a pipeline for occurrences which generate acoustic perturbations therein, comprising: transmitting a monitoring signal through a fiber optic cable, wherein the monitoring signal comprises a pulse of a coherent beam of electromagnetic radiation and a coherence time of the coherent beam of electromagnetic radiation is equal to or longer than a 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; and processing the detected coherent Rayleigh noise to identify a said acoustic occurrence in the section of the wellbore, the reservoir or the pipeline.