Kumar, Abhash (National Energy Technology Laboratory) | Zorn, Erich (National Energy Technology Laboratory) | Hammack, Richard (National Energy Technology Laboratory) | Harbert, William (University of Pittsburgh) | Ampomah, William (New Mexico Institute of Mining and Technology) | Balch, Robert (New Mexico Institute of Mining and Technology) | Garcia, Leonard (New Mexico Institute of Mining and Technology)
A surface seismic network of five broadband seismometers was deployed in the vicinity of a CO2 injection well at an active enhanced oil recovery site in Farnsworth, Texas. We examined and characterized the data collected during the first three months of deployment. Data analysis identified 280 high-amplitude, regional events and a second set of 12 long period, low frequency events. The hypocenters of high-amplitude, regional events are distributed throughout central to western Oklahoma and are unrelated to CO2 injection in the Farnsworth field. The nearest cluster of events in western Oklahoma is >90 miles away from the injection well in Farnsworth. Long period low frequency seismic events observed in this study have emergent waveform characteristics that persist for 30-70 seconds. Spectral analyses of these events revealed a significant concentration of energy in the 0.8-3 Hz frequency range. A finite temporal moveout is observed in the arrival time of recorded long period events across the local seismic array in Farnsworth. These low frequency events have waveform characteristics significantly different from a short period earthquake and resemble long period, long duration (LPLD) events previously reported. The absence of time-correlative signal from the nearby stations of the Oklahoma seismic network and arrival time moveout recorded across the Farnsworth seismic network suggest a local source of slow slip deformation as the cause for long period events observed in this study.
Presentation Date: Wednesday, September 27, 2017
Start Time: 3:55 PM
Presentation Type: ORAL