The usage of Distributed Acoustic Sensing (DAS) in geophysics is rapidly gaining popularity due to its dense spatial sampling and low operation cost, and given that 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 purposefully-designed optical fibers. Such reconstruction uses multiple strain projections acquired by manipulating the geometry of the optical fiber. Similarly, using the same approach the reconstruction of the displacement vector is possible. The availability of the entire strain tensor opens the possibility for accurate elastic wavefield extrapolation, thus avoiding the generation of nonphysical wave modes that contaminate migrated images. This technology also enables high-quality estimation of reservoir properties, and accurate elastic parameter estimation.
Presentation Date: Thursday, October 18, 2018
Start Time: 8:30:00 AM
Location: 212A (Anaheim Convention Center)
Presentation Type: Oral