Effective monitoring of reservoir-induced seismicity utilizing integrated surface and downhole seismic networks

摘要

Many injection processes are monitored through the use of microseismic monitoring at short distances by the detection and analysis of micro-earthquakes. Hydraulic fracturing and cyclic steaming are capable of generating thousands of micro-earthquakes with magnitudes typically ranging from –Mw4 to –Mw 1. The instrumentation and configuration of the microseismic monitoring networks are chosen with this magnitude range in mind, and the relatively high frequency signals are recorded with geophones with the bandwidth necessary for accurate spectral characterization. Also, the recording parameters typically trigger only short-time windows once an event has been detected. While these parameters may be acceptable for the characterization of such small magnitude events, they are not ideal for the characterization of larger magnitude events with Mw>0 to approximately Mw3 because the lower frequency signals emitted by these events will not faithfully be recorded and the pre-set time windows are too short to contain both P and S arrivals.