Abstract
Hydraulic fracturing enables hydrocarbon production from unconventional
reservoirs. Mapping induced seismicity around newly created fractures is
crucial for understanding the reservoir response and increasing the
efficiency of operations. Distributed acoustic sensing (DAS) provides a
large amount of high spatial resolution microseismic data acquired along
the entire length of horizontal wells. We focus on the observed
reflected S-waves and develop a new methodology to image induced
fractures acting as reflectors in the media surrounding the events and
monitoring fiber. The workflow consists of DAS data preprocessing, event
location, wavefield separation, raytracing-based imaging, and image
postprocessing. The comparison of the resulting fracture images with
low-frequency DAS signals with fracture hits corroborates that the
reflections are from fractures created by stimulation. The fracture
imaging algorithm can be used for real-time mapping of fractures and
tracking fracture changes in time. It leads to a better understanding of
the reservoir response to hydraulic fracturing stimulation.