  Distributed acoustic sensing (DAS) fibers have enabled various geophysical
applications in unconventional reservoirs. Combined with perforation shots, a
DAS fiber can record valuable guided waves that propagate in the reservoir
formation and carry information about its properties. However, the
representation of perforation shots as seismic sources, needed to conduct
quantitative analysis, remains unknown. We model such sources using a
superposition of three mechanisms for which we derive the moment tensor
representation. Using field DAS data recorded in the same well where the
perforations are located, we establish a workflow to invert the resolvable
components of the total moment tensor for 100 different perforation shots. By
scrutinizing the inversion results, we conjecture that the moment tensor can
indicate how effectively a perforation shot creates micro-cracks in the
surrounding rock. Furthermore, our inverted moment tensors form the basis for a
subsequent elastic full-waveform inversion.
