Low SNR seismicity detection using features of 3D particle motions of direct P-waves

Detection and analysis of seismicity is valuable for characterizing and better understanding of reservoirs. At the P-wave arrival, particle motion has a linear polarization and the direction of arrival is oriented to the source zone along the ray path. We extract these characteristics of direct P-wave arrivals by evaluating the 3D particle motions and use them for event detection purposes. Particle motion is evaluated using spectral matrix analysis in the time-frequency domain over the frequency band having the highest power. We also use information about reference events in a catalog such as moveout and inclination of direction of arrival to detect events within a particular seismogenic region. We apply our method to field seismicity data recorded at multiple wells each having multiple receivers located in the Groningen gas field The Netherlands. Our method detects previously undetected (buried) events that are not in the catalog.