The use of the Distributed Acoustic Sensing (DAS) technology is gaining traction as the scientific community values its versatility while benefiting ease of deployment. This technology has been applied in a wide range of geophysical applications. The distributed nature of the sensing coupled to the large aperture array enabled by long cable(s) provides robust passive seismic monitoring systems. We developed a simulator of DAS-acquired passive seismic data for Geothermal injection monitoring, which outputs data at real-time speed. The simulator serves for the verification of the acquisition geometry and the processing system when monitoring hydraulically-induced fracture network.