P-wave velocity and attenuation (1/Q) data of water-saturated sand pack (from dry to full saturation) at 10 kilohertz frequency measured using an acoustic pulse tube under 10 MPa effective pressure

The data comprise P-wave velocity and attenuation (1/Q) measurements of water-saturated sand packs (four samples) across saturation levels, from dry to fully saturated. Using an acoustic pulse tube, measurements were recorded in the sonic frequency range (1-20 kHz, centred at 10 kHz) under 10 MPa effective pressure with atmospheric pore pressure. Data were collected in the Pulse Tube Laboratories at the National Oceanography Centre (NOC), Southampton, between March 2022 and January 2023, funded by the Natural Environment Research Council (NERC Grant NE/J020753/1), and primarily collected and analysed by Hanif Sutiyoso (University of Southampton). The experiment aimed to fill gaps in sonic frequency measurements of sediments across saturation states, providing a spectrum of water/gas saturation rather than a single value. This dataset is valuable for researchers analysing saturated sediments and is directly comparable to sonic well-logging field data due to its frequency range. The full dataset has been published at https://doi.org/10.1111/1365-2478.13607.

The method involved measuring time series of signal amplitude from four samples (A to D) inside a 4.5 m water-filled acoustic pulse tube, which allows plane wave propagation in the sediment-jacketed samples. Time-domain data were transformed into the frequency domain using Fast Fourier Transform (FFT) and deconvolved with the chirp source signal to obtain the impulse response. Nonlinear inversion was used to minimize an objective function derived from initial time-domain estimates, determining the sample's complex velocity and attenuation (1/Q).