Applying nonlinear properties of geological media containing hydrocarbons in seismic profiling

Abstract

and the lengths of the record and of the sweep signal were measured over different portions of the profile. During the period of the studies, the position of the seismic receivers didn’t change. This study was based on the fact that, from the theoretical point of view, complicated media saturated with fluids and featuring higher seismic nonlinearity should be distinguished in their difference and sum frequencies against the background of the main field. Therefore, the experiment was aimed at the separation of waves with combined frequencies from the seismic record. They were separated through a correlation of the vibrograms with different sweep signals: main f 1 ‐ f 2 , sum ( f 1 + f m ) ‐ ( f 2 + f m ), and difference ( f 1 ‐ f m ) ‐ ( f 2 ‐ f m ). The vibrograms were processed with the use of ProMax 2D/3D and MATHLAB software. As the goal of the study was the separation of waves with combined frequencies, the processing of the data included the compiling of three time sections with a common depth point: the basic, sum, and difference sections. All the processing parameters were similar for all the three types of sections. When compiling the common depth point sums, the main principle was the maximal possible retention of the dynamic characteristics of the wave field for its subsequent analysis, rather than the acquisition of patterns that were optimal for further structural images.