Using Spectral Attributes to Detect Seismic Tremor Sources - A Synthetic Study

摘要

A method is presented to detect subsurface seismic tremor sources by analyzing surface data. Spectral attributes of the recorded seismic wave-field at low frequencies are used to map the surface projection of the sources. We illustrate the concept on a synthetic data-set and show how spectral attributes can be used for detecting locations of seismic tremor sources. In a second part we apply the method to an example of hydrocarbon reservoir related tremors. The results show that increased complexity of the subsurface seismic properties and/or the presence of several tremor sources can strongly complicate the interpretation. In addition, the presence of dominant surface noise may mask the signals emitted by the subsurface tremor sources and make it impossible to detect them at the surface without additional processing. F-K filtering is successfully applied to noise-contaminated data and retrieves masked anomalies. Care has to be taken for using a proper data-set and proper processing parameters in order to avoid artifacts introduced by the F-K filter. Although we discuss an application for possible hydrocarbon reservoir related tremors, we believe that the methods can also be applied to any other type of seismic tremor signal.