- © 2012 by The Society of Exploration Geophysicists
The proliferation of hydraulic fracturing (frac) stimulation and other enhanced oil recovery techniques in unconventional plays has spurred interest in microseismic monitoring. Changes in stress in the subsurface produced by hydrocarbon production may induce brittle failure events. Many enhanced oil recovery techniques such as hydraulic frac stimulation or cyclic steam stimulation involve injecting large volumes of fluid at high pressure into a reservoir. Microseismic events, hereafter events, may illuminate the reach and effectiveness of enhanced recovery techniques within a reservoir. When array configuration is favorable, advanced analysis of microseismic data may provide additional information. For instance, seismic moment tensor inversion (Eaton and Forouhideh, 2010) may estimate the failure mode of an event. The aforementioned failure modes may include fracture-opening, shear, or fracture-closing events. Knowledge of the failure modes allows a detailed analysis of the effects of changing parameters such as steam injection temperature or well spacing.