Аннотация:Repeat downhole measurements of elastic properties would be extremely valuable for constraining 4D seismic inversion. However, intervention into wells to conduct such measurements is difficult and, in rarely used in practice. Distributed fiber optic sensing allows monitoring changes of formation properties, which could affect properties of the fiber-optic sensor: alter refractive index, cause physical deformation or the way the laser pulse is scattered. DAS is already often used to monitor production noise, microseismic activity and used as a sensor in 4D VSP surveys. In this presentation we demonstrate how distributed acoustic sensing could be used to monitor changes in elastic properties of the formation by monitoring local changes in seismic wave amplitude.