A matched filter technique that uses cross-correlation and migration of the recorded waveforms has been successfully used to relatively locate microseismic events. In addition to producing consistent relative locations, the matched filter corrects for radiation pattern effects and near-surface structure. The relative locations produced using this methodology were compared with a proprietary, direct location method. The new results produce a solution set that reveals two parallel trends of microseismic events which are interpreted as 1500' long fracture zones approximately 100' wide. We observed asymmetric fracture growth and re-fracturing of the previously stimulated zones. Time correspondence of the observed evolution of seismic events with engineering pump curve data reveals approximate linear growth rates of several feet per minute and possible proppant placement along the induced fractures.

Keywords:
Upstream Oil & Gas, microseismic event, hydraulic fracturing, Slave event, Artificial Intelligence, direct location method, master event, Filter Technique, seismicity, surface array
Subjects:
Hydraulic Fracturing, Reservoir Characterization, Seismic processing and interpretation
Copyright 2009, Society of Petroleum Engineers
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