Directional analysis of high-frequency source using seismic physical modeling

Abstract:

High-resolution seismic exploration uses high-frequency source to acquire high-resolution seismic image. A high-frequency source does not transmit on the omni direction because of its directionality. Therefor, it is difficult to apply it to general seismic data processing. In order to apply data processing to the acquired high-frequency signals, the characteristics of directionality must be considered. In particular, directional analysis is essential for high-resolution 3D seismic exploration. The seismic physical modeling is an experiment in which the exploration area, exploration equipment, etc. are reduced to the laboratory scale. Because it acquires seismic wave that actually propagate, it has the advantage of simulating seismic exploration. This study analyzed directionality of a high-frequency source using seismic physical modeling as a preliminary study for performing high-resolution seismic data processing.

In order to analyze the directionality of a high-frequency source, signals according to angles and offsets were acquired in an isotropic medium. Signals were generated using pulser/receiver, and transducers of 1 MHz and 2.25 MHz were used as source and receivers. Signals were acquired using a digital oscilloscope. The receivers were arranged at intervals of 10° within the range of 0° to 180°. The signal acquired according to the angle was analyzed for directionality by extracting the maximum amplitude. As a result of the analysis, it was strongly radiated in the central axis(90°) direction. The direction according to offset was analyzed by fixing the source and moving the receivers. The higher the frequency, the more rapidly the amplitude varied with the offset.

In this study, the directionality of the high-frequency source was analyzed by acquiring the signals according to the angle and offset. The results of this study are considered to be used as basic data for the development of high-resolution seismic data processing algorithm.

Acknowledgement

This research was supported by the Basic Research Project(20-3312-1, 20-3313) of the Korea Institute of Geoscience and Mineral Resources(KIGAM) funded by the Ministry of Science, ICT and Future Planning of Korea.