MICROSEISMIC EVENT LOCALIZATION USING BOTH DIRECT-PATH AND HEAD-WAVE ARRIVALS

摘要

The present invention relates to methods and apparatuses for using head waves to greatly improve microseismic event localization accuracy, particularly in the depth dimension, by analyzing them in addition to direct path arrivals whenever they are observed. Embodiments include techniques known as multipath analysis. According to certain aspects, new event localizations are examined as a function of proximity to internal physical structures found within a 3D seismic depth volume through calculation of interface curvature and seismic incoherence. The results indicate a correlation between the deteraiined event locations and computed seismic properties, indicating that the increase in event localization accuracy achieved may have been sufficient to enable observation of a relationship between the spatial distribution of induced microseismic activity and identified internal physical structures.