Advances in Vibroseis Technology Enhance Low Frequency Recording and Provide Significant Operational Benefits

Abstract

Introduction Advancements in source and receiver technology in recent years will have a dramatic impact on low frequency data. Substantial improvements have been made by modifying the vibroseis with the goal of eliminating generated noise and enhancing and understanding the force output of the vibroseis. Combining this technology with the low frequency performance characteristics of the digital sensors, high quality, low frequency results are possible in nearly any environment. Together these technologies provide a distinct added value to seismic acquisition. Using vibroseis technology to sweep smarter rather than harder can mean superior seismic data with no additional cost or effort. Innovations in Vibroseis Technology Vibroseis technology has undergone extensive improvement in recent years. Modern engineering methods have been systematically applied to meet the basics of mechanical constraints. By studying all the components of the Vibroseis system, it has been possible to improve low and high frequency performance, reduce harmonics, and increase the accuracy of sweeps in terms of fundamental ground force. In production shooting, the benefit of current technology combined with sweeps designed to meet low frequency requirements produces significant energy output as low as 1–3 Hz. The integration of multiple innovations makes this achievement possible. One result of Vibroseis technology development can be seen in the benefits possible with sweep design. Designing a vibroseis sweep based only on the desired outcome of the frequency content of the final data is a common practice. However, it can be shown that by designing a sweep with the desired frequencies filtered by the performance characteristics of the vibroseis, a better result can be obtained. This particularly applies to the low frequency portion of the frequency spectrum. Examples show one such case in point. The customer designed a linear sweep from 5–86 Hz. The low frequency portion of this sweep design is not consistent with performance characteristics of the vibroseis utilized, so an alternative sweep design was proposed. to limit the amplitude effort in the lower portion of the frequency spectrum to the vibroseis characteristics. Sweeping with the modified sweep and correlating, achieves a superior result. Most noticeably, there is a dramatic decrease in ground roll in the shot that is correlated with the modified sweep. The impact of the reduction in ground roll cannot be overstated.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015