Detecting long-period long-duration microseismic events during hydraulic fracturing in the Cline Shale Formation, West Texas: A Case Study

摘要

A reservoir's well production rates can be enhanced by hydraulic fracturing. Predicting a formation's response to this stimulation is of great importance to understanding the total deformation that results from hydraulic fracturing. Long-period long-duration (LPLD) waveforms are a dominant deformation mechanism during hydraulic stimulation (Zoback et al. 2012). If this assertion is correct, then it is important to detect and locate where these unusual events occur in order to better understand this slip mechanism. We evaluated microseismic data recorded by means of downhole and surface array acquisition during the hydraulic fracturing of a horizontal well located in Glasscock County in the Permian Basin to detect the presence of LPLD microseismic events. LPLD waveforms were detected in the downhole acquired data, but the examination of the data recorded on the surface geophones did not reveal the presence of slow slip motion most likely due to the low signal strength. Because of the long duration of these events, no distinct P or S arrivals, and the characteristic of being dominated by low frequencies, LPLDs are likely to go unnoticed in the analysis and interpretation methods applied to conventional microseismic events.