Multicomponent imaging with distributed acoustic sensing

The usage of Distributed Acoustic Sensing (DAS) in geophysics is rapidly gaining popularity due to its dense spatial sampling and low operation cost if the optical fiber is easily accessible. In the borehole environment, optical fibers for DAS are often readily available as a part of other sensing tools, such as for temperature and pressure. Although DAS provides single axial strain measurement along the fiber, the entire strain tensor can also be recovered through a combination of purposefullydesigned optical fiber system. Such reconstruction uses multiple strain projections acquired by manipulating the geometry of the optical fiber. The availability of the entire strain tensor opens the possibility for exact elastic wavefield extrapolation, thus avoiding the generation of nonphysical wave modes that contaminate migrated images.