Conditioning Distributed Acoustic Sensing Measurements for Borehole Seismic Imaging

Abstract

Distributed acoustic sensing (DAS) differs from particle velocity measurements in both amplitude and frequency response. DAS data are affected by the apparent velocity of the incident energy relative to the fiber as well as the gauge-length at which the fiber is interrogated. We develop a generalized relationship for dependence of the DAS amplitude response on the incident elastic waves in terms of the angle of wave vector, angle of polarization, and phase velocity. Velocity and DAS sensor synthetic data are generated to comprehensively evaluate the conditioning methods needed to prepare DAS data for imaging. DAS sensor images, using data-driven and model-driven approaches, are shown to be consistent with the reference velocity sensor image.