Automatic deployment of a 2-D geophone array for efficient ultra-shallow seismic imaging

Abstract

The cost of three-dimensional seismic-reflection surveys is approximately inversely proportional to the square of the target depth, which renders ultra-shallow 3-D surveys uneconomical when employing conventional acquisition methods. We developed instrumentation that automatically deploys an array of geophones for efficient acquisition of shallow 3-D seismic reflection data. The components of the instrumentation are: a rigid-steel platform used for positioning, planting, and transporting geophones; a hydraulically controlled mechanism for decoupling the geophones from the platform during seismic-data recording; and a 2-D array of 72 geophones. Tests of both automatically planted geophones and conventional hand-planted geophones resulted in comparable ultra-shallow seismic data. Field tests show automatic planting and moving of the geophone array is possible in three minutes by one or two field operators. Conceptually, the design could accommodate hundreds of geophones handled by a single operator. The instrumentation presented is a new approach to efficient ultra-shallow 3-D seismic acquisition.