Influence of fiber-optic cable structure, sand density, and acoustic frequency on DAS amplitude response: Preliminary results

Abstract

Distributed acoustic sensing (DAS) is an emerging fiber-optic technology that can turn tens of kilometers long fiber-optic cables into dense acoustic sensor arrays. This technology is expected to bring new opportunities for geologic hazard characterization and mitigation. The cable structure and installation method are two critical factors affecting the performance of a DAS system. Here, we report laboratory tests performed in a sandbox to evaluate the acoustic response of different types of cables at variable sand densities and acoustic frequencies. Our initial results indicated that complex cable packaging structures had unfavorable impacts on the DAS amplitude response whereas the influence of sand density was dependent on cable structure and acoustic frequency. Further tests with refined measurement setup will improve the understanding of the combined effects of cable type, medium density, and acoustic frequency on DAS recordings.