Abstract
Research on the seismic nonlinearity of rocks began in Russia in the 1980s . The first stage of this experimental and theoretical research established that the geologic environment is seismically nonlinear and the nonlinearity sufficient to be recorded by existing systems. However, this initial research did not focus on solving practical problems of reservoir analysis
Consequently, the authors conducted field experiments using standard vibroseis equipment, that focused on using the nonlinear component of field records for discovering hydrocarbon reservoirs and determination of their properties. We believe this is one of the first such experiments to be done or published
Our results show that in porous, permeable, and oil-saturated rocks the following can be observed on the records of vibroseis surveys
The relationship of recorded wave amplitudes to source amplitudes is nonlinear
Several frequencies (harmonics) and combinational waves of subtractive and combined frequencies are present
Reservoirs are seismically active
We feel that, because of these properties, using seismic nonlinearity should allow creation of more accurate reservoir models