BEAM FORMING WITH VIBRATOR ARRAYS

Abstract

Seismic field tests conducted near Tulsa, Oklahoma, and the Handy area in north‐central Texas used linear arrays of vibrators to concentrate sound waves into a beam, which is directed vertically when all vibrators operate in‐phase or at an angle from the vertical when relative time delays are introduced to each vibrator. The sound wave directivity was verified in the Tulsa area by recordings from subsurface seismometers, and at the same time reflection enhancement by wave beaming was exhibited from surface seismometers. Visual inspection and statistical analysis of reflection continuity indicated that it makes no difference in the Handy area whether beam‐forming techniques are used in the field or are applied later in processing. This result was anticipated, since previous seismic work in the Handy area indicated that the random noise level was low enough to minimize the theoretical advantage of field summing.