Frequency characteristics of perforation and fracturing induced microseismic events recorded by downhole and surface arrays

Surface microseismic monitoring of hydraulic fracturing is now becoming more and more popular in the production of unconventional hydrocarbons. The frequency analysis of surface detected microseismic event and comparison with perforation event and downhole recorded event may lead to deeper understanding of the frequency variations of microseismic events and contribute to the development of innovative filtering techniques. In this paper, two microseismic events detected by surface arrays, one microseismic event and one perforation event recorded by downhole geophones are presented. S-transform is used to derive the time frequency representations of these events. The frequency contents of these three types of microseismic events are characterized and compared with each other.