TSP and VSP

Knowledge about rocks characteristics beyond the excavation face of tunnels or beneath the bottom hole of a well has always been part of underground engineering and geological research. The seismic reflection technique known as T.S.P. (Tunnel Seismic Prediction) used for exploration on the excavation face of tunnels, is the evolution of the original V.S.Pp. technique (Vertical Seismic Profile prediction), used in wells for hydrocarbons. The T.S.P technique reduces “geological surprises” to a minimum, allowing for detailed prior verification of critical zones, previously identified by standard geotechnical and geomechanical tunnel profiles. T.S.P method can provide advanced geological prediction for 100 meters ahead of the tunnel face and up to 150 m in hard rock masses. The V.S.P technique may forecast the presence of reflectors (lithological contacts) for hundreds of meters further beyond the well bottom.