Crosswell versus surface ambient noise seismic interferometry: A numerical analysis

Document Type

Presentation

Publication Date

2017

Department

Department of Geological and Mining Engineering and Sciences

Abstract

Ambient noise seismic interferometry (ANSI) is a cost-effective method to study a reservoir through time-lapse surveys. Numerical modeling allows us to test a variety of acquisition strategies before employing them in the field. In this study, we compare crosswell and surface acquisition configurations to retrieve body waves using ambient noise seismic interferometry through forward modeling and subsequent processing of the model results. The area containing the noise point-sources is varied to examine whether the crosswell geometry can effectively utilize high-angle noise. Crosswell ANSI is found to be plausible, but the method of analysis using cross-correlation proves to be the limiting factor in this study. That is, cross-correlation is not an effective method for stacking of coherent reflection information if part of the crosswell array is close to the noise sources. This proximity causes reflection signals to be significantly different between geophones near the surface and those at depth, close to the noise sources. In addition, the repeatability of such surveys is poor, due to the strong effect that small changes in noise-source location can have on the signals observed at nearby receivers.

Publication Title

SEG Technical Program Expanded Abstracts 2017

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