Field trials of distributed acoustic sensing for geophysical monitoring

Abstract

Distributed Acoustic Sensing (DAS), a rapidly evolving fiber‐optic based technology for permanent in‐well and geophysical monitoring, was used to record VSP data in two field trials in Shell assets onshore Canada and USA. Useful in‐well velocity data were gathered from the entire length of the well from wellhead to TD (up to 4 km), which compared well with geophone recording and sonic log data. Walk‐away VSP data yield images that are nearly equivalent to images from conventional borehole geophones in terms of signal to noise ratio and resolution. Permanently installed fiber‐optic infrastructure will enable low‐cost non‐intrusive geophysical monitoring.