Fracture imaging using DAS-recorded microseismic reflections

Distributed acoustic sensing (DAS) is a rapidly developing technology that can be used for characterizing the geometry and propagation of hydraulic fractures. DAS provides observations of microseismic wavefields with high spatial resolution, which contain direct P- and S-arrivals as well as converted and reflected signals. In addition to traditional approaches for microseismic event location and source mechanism analysis, DAS recordings can be used to image induced fractures using reflections. The reflections may be generated by hydraulic fractures from earlier treatment stages. We use a simple method based on f-k filtering and ray-tracing to map reflections from the data domain to the model domain. Fracture images can then be integrated with low-frequency DAS and microseismic clouds to further characterize dynamic fracture propagation.