The Vibroseis system: A high‐frequency tool

Abstract

Exploration methods are extended to their limits as we continue the search for energy resources. Successful application of high‐frequency seismic method requires evaluating each element in the seismic acquisition system and ensuring that each part of the system contributes to the success of the method. This extends from seismic signal generation through data processing where good equipment performance and correct parameter selections are required. The Vibroseis® system depends upon the ability of vibrators to generate synchronous, repeatable sweeps over the frequency range of interest. To support our high‐frequency seismic efforts, Conoco, Inc., has developed and built a new high‐frequency vibrator. This paper includes some of the consideration used in building the vibrator, along with typical baseplate responses showing excellent drive levels to the design goal of 200 Hz. With an excellent source available, correct application is essential to assure retention of high‐frequency data. Recording offsets, array lengths, and array sampling must be selected for the sweep frequencies used. Also, approximate matching of the data acquisition system response to the spectral response of the earth reduces the dynamic range requirements for recording systems and subsequent data processing. Data are included showing the successful application of high‐frequency techniques to stratigraphic exploration problems.