Thomas Bianchi

Harmonic Noise Reduction Opens the Way For Array Size Reduction In VibroseisT Operations

To compensate for the reduced number of vibrators per shot point required by reductions in group interval and array size, either the recording time per surface unit must be increased or high order simultaneous recording techniques such as the slip sweep technique should be used. Yet these techniques suffer from distortion, which contaminates the data in proportion to the productivity increase generated. A method to significantly reduce this contamination is presented. . Introduction

V1: Implementation and application of single-vibrator acquisition

In land seismic operations, there is a strong drive to improve both quality and performance to meet the increasing demand for high-density and wide-azimuth recording.

Pseudo-random coded simultaneous vibroseismics

Simultaneous recording is coming back as a center of interest for acquisition teams, for productivity (Rozemond, 1996) or quality improvement (Baeten et al, 2000) or for multi-source monitoring (Meunier et al, 2001). Methods involving phase encoded sweeps are limited, due to harmonics and correlation side lobes. Such problems could be overcome using the ability to submit digital signals offered by new vibrator electronics.

Efficient Wave Field Sampling in Vibroseis Operations.

Summary It has been observed on multiple occasions that after full processing, residual organized noise depends on source and receiver line intervals. An explication of this observation is proposed and illustrated by a recent single vibrator experiment in Egypt.