Nonlinear Filtering for Detection and Location of Microseismic Events: Generalization of Nonlinear Stacking Methods
A. Özbek, T. Probert and A. Gendrin
Event name: 80th EAGE Conference and Exhibition 2018
Session: Microseismic Waveform Detection And Inversion
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 1.65Mb )
Price: € 20
Reliable detection of weak signals is potentially a fundamental limitation for microseismic event detection and location, especially for sensors in the near-surface region, where large source distances and high noise levels affect the signal-to-noise ratio (SNR). Previously, a nonlinear stacking method was introduced that could increase the SNR for weak signals and included methods that are insensitive to changes in signal polarity. This paper introduces nonlinear filtering methods that are a generalization of the nonlinear stacking method where the stacking operation is replaced by a filtering operation. This method keeps the SNR and polarity benefits of the stacking methods, but we can now choose to modify the pass and reject bands. For instance, we can improve the SNR for weak signals, with polarity changes, and allow additional signal misalignment criteria to be included in the pass-band. We will show synthetic-signal and real-signal examples where the new method has clear benefits compared to conventional stacking or other nonlinear stacking methods.