Seismotech will present the following reports at the 3rd international geological and geophysical conference and exhibition: "GeoEurasia-2020. Advanced Exploration & Development Technologies" in Moscow, February 3-6, 2020.
1. "Signal enhancement - between processing and interpretation"
Shalashnikov* A., "Seismotech, Ltd."
2. "Influence of signal phase spectrum on robust deconvolution results"
Kunchenko* D., Shalashnikov A., Finikov D., "Seismotech, Ltd."
3. "Possibilities of distortion correction of seismic signals dynamic parameters during seismic processing on the basis of wave fields modeling"
Vlasov S. (“RN-BashNIPIneft”), Ovchinnikov* K., Shalashnikov A., "Seismotech, Ltd."
More details below:
The report deals with the ways of improving the quality of seismic images and obtaining a set of attributes required by interpretation.
These are the procedures of the final stage of processing, i.e. the part of the so-called "signal processing" which is executed on the results of migration - cubes and/or CIG (common image gathers).
In particular, we will also cover some questions about the suppression of artifacts due to the effects of observation geometry (the so-called footprints), spatial and temporal resolution improvement, traceability of reflections, etc. The application of the software at this stage is to improve the quality of the images and/or obtain new images to solve specific interpretation tasks. These tasks determine the choice of certain algorithms.
The key provision, declared and illustrated in the report, is that the criteria used to determine the quality of images (and the choice of ways of achieving this quality) should be different for different dynamic and structural tasks.
Deconvolution can significantly change both the form and amplitude of the signal which are the key characteristics used for dynamic interpretation.
However, high resolution of seismic data - restoration of the spectral characteristics in high and especially low frequencies - is a necessary condition for solving inversion problems.
Therefore, the robust deconvolution procedure is required at the final stages of processing. It is often included in the dynamic inversion algorithms as one of the stages of the procedure.
The question about the phase spectre of the signal is one of the key points affecting the reliability of the results. Some special aspects about the phase spectre of the signal in the procedure of robust deconvolution will be discussed in this report. The results are illustrated by examples on real and simulated data.
The report highlights the results of work on wave fields modeling to develop methods of processing and interpretation in specific seismological conditions. This work is a continuation of a major project that began to explore the possibilities of solving structural problems.
If in the previous project the usage of radial modeling was sufficient, then in this project it was necessary to use methods more accurately describing the dynamic characteristics of the signals. The method of layer-by-layer recalculation of wave fields was applied. Reflected, exchangeable and refracted waves of the specified code were calculated, and frequency-dependent absorption was also taken into account. The complex model was prepared on the basis of detailed geological information. The results of modeling were processed according to the standard graph and analyzed the distortions of dynamic parameters on the deep images (seismograms of the common image point in the angular sweeps). The questions of correctness of transformations, the suitability of processing results for solution of interpretation tasks are discussed.
Synthetic data can also serve as a basis in order to explore the possibilities of new processing algorithms aimed at preserving the dynamics of useful waves.