Sonic log data extracted from exploration wells in the ViDEPI project (offshore the Apulia, southern Italy)
Description
Twelve files have been obtained after the extraction of data from raster images (PDF format) of as many sonic log graphs of exploration wells. The files data refer to the exploration wells located in the Adriatic Sea offshore the Apulia, whose raster images of sonic logs are public within the ViDEPI Project (www.videpi.com) of the Ministry for the Economic Development of the Italian Government. Each file is composed of two columns of data A and B, that are interval transit time Δt [µs/ft] and depth [m], respectively. Therefore, a total of 18396 pairs of Δt-depth data have been extracted. The pair of Δt-depth values resulted in CSV file format for the sonic logs of each of the following exploration wells: Branzino-1, Chiara-1, Cristina-1, Famoso-1, Giove-1, Giove-2, Grazia-1, Grifone-1, Medusa-1, Sabrina-1, Simona-1, and Sparviero-1bis. As known, the sonic log is a Δt-depth diagram, where Δt is the interval transit time; the unit of measurement of Δt is µs/ft (µs = microseconds, ft = feet), and that of the depth is m (m = meters). For the interpretation of the seismic profiles, it is important to distinguish the net variations of Δt, that are related to sudden variations of acoustic impedance, which in turn depends by lithostratigraphic features. It is worth mentioning that for each lithostratigraphic succession the calculation of the (i) average interval transit time easily allows the obtaining of the (ii) seismic P-waves average velocity: the latter is the reverse of the first. The unit of measurement of seismic P-waves average velocity, which is thus ft/µs, can be converted in m/s (m = meters, s = seconds), taking into account that µs = 10-6 s, and ft = 0.3048 m. The data are important for geologists who interpret the reflection seismic profiles located in the Adriatic Sea, chiefly offshore the Apulia; the interpreters of the seismic profiles placed in the adjacent offshore areas, i.e., the Ionian Sea, can benefit from the data making appropriate correlations. Furthermore, the data can be helpful also for seismological purposes around the Apulia.
Files
Steps to reproduce
The data were picked using the free software WebPlotDigitizer© (Author: Ankit Rohatgi, Website: https://automeris.io/WebPlotDigitizer, Version: 4.6, Date: September, 2022, E-Mail: ankitrohatgi@hotmail.com, Location: Pacifica, California, USA). Each PDF file, representing the sonic log, has been loaded. Consequently, the default format 2D (X-Y) Plot has been selected. X-Y axes have been aligned to Δt-depth axes of the sonic log, fixing for X1 the minimum value of Δt, for X2 the maximum value of Δt, for Y1 the depth of the sea floor and for Y2 the depth of the exploration well bottom. Therefore, the digitization of the peaks of each sonic log sawtooth function manually occurred. Finally, the pair of Δt-depth values resulted in CSV file format for the sonic logs of each of the exploration wells. The data can be reproduced in Δt-depth diagrams by the using of those software able to construct 2D graphs from data in CSV files (e.g. Matlab©).