Reducing noise is paramount when doing surface microseismic monitoring as the signal-to-noise ratio is usually lower than one. In fact denoising can significantly improve results since there are many more small microseismic events rather than large ones. It is shown here that efficient denoising can be obtained during the acquisition phase by deploying the geophones into small, dense arrays called patches. The patches ensure a 20dB noise reduction in all of the directions, while the traditional radial-shaped designs suppress noise only in the inline direction. This is particularly important as many noise sources are present in the monitored area, not only at the fraccing pumps whose noise is present only on about 1% of the network. Moreover, the patches are independent arrays. This indicates that non-permit areas can easily be avoided, and also that low-noise areas can be chosen in order to deploy the patches. This, combined with their intrinsic denoising capabilities, suggests that the overall signal-to-noise ratio can be greatly enhanced.

This content is only available via PDF.
You can access this article if you purchase or spend a download.