49 QUAL I TÉ GÉOPHYSIQUEAPPLIQUÉE 2 Well seismic surveying 4 J.-L. Mari, C. Vergniault, F. Coppens 2.1 Introduction Well seismic surveying, the most commonly used form of which is Vertical Seismic Profile or VSP (Hardage 1985, 1992; Mari et al., 1999, 2003), is a seismic method involving a signal that is emitted on the ground surface, which is then recorded by a seismic receiver located at various depths in the well. The earliest type of well seismic measurement is the check shot survey, which is used to measure propagation times between the surface and various well depths. VSP is a well seismic method for which the source and the receiver are considered to be on the same vertical. The VSP vertical resolution ranges from meters to tens of meters and its lateral range of investigation can reach a few tens of meters (Fresnel zone). VSP is based on the analysis of different wave trains recorded by the well receiver. The measurement of the arrival time of the first downgoing waves that propagate close to the near-normal incidence is used to provide a velocity distribution in the This chapter of Well seismic surveying and acoustic logging is published under Open Source Creative Commons License CC-BY-NC-ND allowing non-commercial use, distribution, reproduction of the text, via any medium, provided the source is cited. © EDP Sciences, 2018 DOI: 10.1051/978-2-7598-2263-8.c004
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