UC Berkeley

In this paper, we show that the location of microseismic events can be significantly improved by incorporating information on head wave arrival time. The traditional method of using direct arrival times and P-wave polarizations leads to increased error due to the large uncertainty in polarization. We integrated head wave arrival time to P- and S-wave arrival time to achieve better resolution in microseismic event location. To this end, we developed a Bayesian inference framework for joint event location and velocity model calibration. The developed method was applied for both microseismic event as well as perforation shot location in a project in Marcellus shale. Comparison with location results provided by contractor shows that the developed method can effectively improve the accuracy of microseismic event location. Based on the improvement, we propose a new acquisition geometry and strategy to reduce microseismic monitoring cost and improve event location accuracy.