Migration-based seismic trace interpolation of sparse converted phase micro-seismic data

Abstract

SUMMARYMulti-component elastic seismic data collected at large offsets have the potential to be used in micro seismic imaging and monitoring. However, types of receiver surface deployments used for micro-seismic monitoring are generally very sparse, and thus the data used for imaging from these receivers cause receiver-migration-operator artifacts that severely contaminate the shallow part of the image. In this study, we present a data-driven method that alleviates these imaging artifacts. The method is based on converted-phase elastic seismic migration and de-migration. We show that despite the spatial aliasing of the recorded data, we are able to suppress the receiver migration-operator artifacts and reconstruct the shallow part of the image. The merit of this approach is that it is elastic, fully data-driven (i.e, independent of source parameters), and does not suffer from migration operator source aliasing, when a small number of shots or micro-seismic events are used. We present a derivation of the method and test it with a synthetic model and a field data set from a geothermal reservoir with abundant natural and induced seismicity.

Converted-wave seismic imaging: Amplitude-balancing source-independent imaging conditions

“…The results with the Marmousi II model show that the SICW-ICs are robust with respect to variable V P ∕V S and density models. The result for the crosscorrelation SICW-IC with variable density only is presented by Shabelansky et al (2014).…”

“…Equivalent forms of the ICs in equations 9 and 10 can be derived in the frequency domain as in Claerbout (1985). By taking the numerator only, we obtain an explicit crosscorrelational SICW-IC form (Shabelansky et al, 2014):…”

“…However, when source information is not available, seismic images cannot be constructed using Claerbout's approach. An alternative approach is to use interference between different wave types propagated backward in time from receiver locations only (Nihei et al, 2001;Xiao and Leaney, 2010;Brytic et al, 2012;Shang et al, 2012;Shabelansky et al, 2013aShabelansky et al, , 2014. We call this imaging condition the source-independent converted-wave imaging condition (SICW-IC).…”

The sensitivity of converted-phase extended images to P- and S-wavespeed variations

“…Converted phase (CP) waves are an integrated part of the recorded elastic seismic signal and are investigated in numerous studies in the research areas of VSP data (e.g., Esmersoy, 1990;Stewart, 1991;Xiao and Leaney, 2010), surface reflection (e.g., Purnell, 1992;Stewart et al, 2003;Hardage et al, 2011) and transmission seismic data (e.g., Vinnik, 1977;Vinnik et al, 1983;Bostock et al, 2001;Rondenay et al, 2001;Shang et al, 2012;Brytic et al, 2012;Shabelansky et al, 2014). In particular, e.g., Xiao and Leaney (2010) and Shang et al (2012) show that converted phase seismic images can be calculated using one elastic wave propagation without using source information (i.e., location, mechanism, time-function), and may have higher resolution and fewer artifacts than reflection type imaging (Shabelansky et al, 2012).…”