Quantifying and Analyzing the Signal-to-Noise Ratio in Down-Hole Seismic Testing

Seismic traces are obtained during the seismic cone penetration test (SCPTu). These traces are compared to determine the propagation time, which is used to calculate seismic wave velocities. We present a method to quantify the quality of the trace by calculating the signal to noise ratio (SNR). We analyzed a set of 25 SCPTu profiles to investigate how SNR degrades with increased penetration depth. We show that signal-stacking repeated seismic tests can be used to mitigate the loss of signal to noise ratio without a significant penalty to the production rate of the seismic cone penetration test at typical test depths. Our work has implications in the development of best-practice down-hole seismic testing. This may improve the confidence in the reported shear wave velocities and lead to improved shear wave velocity applications.