THE GEOSEIS SYSTEM

Abstract

In the past decade the exploration industry developed and used many types of land seismic sources, some of which have been surface sources designed to overcome the problems associated with conventional drilling techniques.

Since its inception during 1966, the Geoseis* system has been used extensively as an exploration tool in many countries and has distinguished itself as a successful surface energy source system.

The Australian exploration industry has seen only a limited utilization of the Geoseis system due to the reduced level of activity and consequently has not had the opportunity of becoming familiar with its characteristics.

To obtain an evaluation of the system, it is necessary to compare its characteristics with those of other successful energy source systems in use today.

In designing a suitable field system, the geophysicist must consider a combination of variable factors which contribute to obtaining optimum seismogram quality. To achieve this quality, it is necessary to have an understanding of the basic theory associated with the system.

Variations of charge length, charge weight and charge separation are important factors in obtaining optimum frequency content, frequency response and acceptable signal -to -noise ratios, while calculation of recording offsets will enhance reflections from particular target horizons.

The Geoseis system is one of the most flexible energy source systems in use today and has the added advantage of incorporating explosives in a surface source system thereby retaining many of the advantages of the conventional dynamite technique.