Geophone Coupling Match and Attenuation Compensation in Near-Surface Seismic Exploration

Abstract

An effective geophone-to-ground couple is often difficult to achieve in loose sediment. Unconsolidated sediment can significantly attenuate the high-frequency component of seismic data. Consequently, the resolution and signal-to-noise (S∕N) ratio of seismic data are adversely affected. In order to minimize these effects, two approaches for enhancing seismic reflection data on the basis of ancillary measurements are demonstrated. A coupling match filter was derived by using single trace seismic data from a Seismic Wave Detect System (SWDS) and common receivers under equivalent conditions. The filter was applied to convert a common shot gather to a SWDS shot gather. The high-frequency loss components in stacked data were corrected by an attenuation compensatory inverse filter constructed from uphole seismic data. The results show that the resolution of seismic data from the coupling match filter is nearly equivalent to that of the SWDS data. In addition, the resolution and S∕N ratio were enhanced by the compensatory attenuation inverse filter. These filters can be applied separately or in combination to improve the data quality and compensate high frequency loss in the seismic data without significantly affecting low frequency content.