Passive acoustic resonator for fiber optic cable tubing

摘要

A passive acoustic system and a method of utilizing the passive acoustic system in a subsurface borehole are discussed. The method includes disposing the passive acoustic system in the borehole, the passive acoustic system including at least one passive acoustic resonator, and monitoring a frequency of an acoustic signal at the at least one passive acoustic resonator. The passive acoustic system includes a protective tubing, a fiber optic cable disposed within the protective tubing, a fluid layer between the fiber optic cable and the protective tubing, and at least one passive acoustic resonator, the at least one passive acoustic resonator representing an area within the protective tubing having a known geometry, wherein the fluid layer affects a frequency of an acoustic signal obtained from the at least one passive acoustic resonator.

主权项

1. A method of utilizing a passive acoustic system in a subsurface borehole, the method comprising:
disposing the passive acoustic system in the borehole, the passive acoustic system including at least one passive acoustic resonator; monitoring a frequency of an acoustic signal at the at least one passive acoustic resonator and determining properties of wellbore fluid, the determining including identifying an ingress of the wellbore fluid into the passive acoustic system, based on the frequency of the acoustic signal and a known geometry of the at least one passive acoustic resonator.