Vertical seismic profile surveys (VSP) provide a unique opportunity to obtain high-quality seismic images of the subsurface. Placing receivers downhole mitigates many near-surface and overburden challenges associated with surface seismic imaging and results in improved image quality. Unfortunately, these benefits are restricted by the limited area illuminated by the primary P-wave reflection wavefield (typically a relatively narrow cone that underlies the geophone array). The free-surface multiple wavefield recorded in a VSP survey illuminates a significantly larger area, both vertically and laterally, and so can provide an expanded imaging capability (Jiang et al, 2005; Jiang et al, 2007; Lou et al 2007). Subsurface imaging using the multiple wavefield has been demonstrated and is commonly used for imaging deep-water 3D node surveys, which are typically acquired using a sparse distribution of receivers. However, no case studies have been published yet, which present a critical analysis of the images provided by this technology when applied to VSP surveys.

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Seismic imaging during piling may reduce construction costs in sensitive areas, and combined with technology to look ahead of the pile tip, the risk of stopping the piling before reaching the bedrock may be reduced. Seismic images obtained during piling can give vital information about the subsurface structure in the vicinity of the pile. In this paper, we discuss how to produce seismic images as a part of the piling procedure without using any external seismic sources. Using surface and borehole synthetic data examples, we show that it is possible to use pressure (P) waves emitted from the pile tip for imaging purposes. A pilot field study was carried out to test the feasibility of this method. The field study revealed that high‐frequency pressure waves are emitted from the pile tip. However, they are masked by strong surface and shear waves, especially at the nearer offsets. The data processing approach allowed us to achieve reasonable signal‐to‐noise ratio for pressure waves at the further offsets, while the signal was not as well recovered at the nearer offsets. This study demonstrates that it is possible to acquire fair‐quality signals without using any seismic source other than the impact on the pile itself. More field data are needed and some acquisition procedures need to be optimized before the method can be applied for practical imaging.