ESTIMATION OF COMPENSATION OF INFLUENCE OF LOCAL INHOMOGENEITIES OF THE UPPER PART OF THE SECTION ON A WAVE FIELD IN SEISMIC EXPLORATION

Abstract

. A scheme for operational quality control of seismic data processing at the stage of calculating long-period static corrections is proposed. Taking into account long-period velocity inhomogeneities in the upper part of the section by entering static corrections in seismic traces is a generally accepted means of improving the accuracy of structural constructions and is often used in the processing of seismic data. But not always calculated corrections can completely minimize the impact of the upper part of the section. This is primarily due to the fact that underreporting practically does not prevent in-phase summation of useful waves, or, in other words, it does not distort the hyperbolicity of the observed hodograph. The consequences of not taking into account the low-frequency component have a significant impact on the accuracy of determining the kinematic parameters of reflected waves and on further construction of deep surfaces. The proposed method allows you to quickly assess the quality of this compensation. The algorithm for evaluating the quality of accounting for long-period static corrections is based on identifying local deviations in the seismic section of the arrival times of reflected waves and their repeatability at several levels. The information accumulated in this way makes it possible to filter out random and select only regular inhomogeneities. The scheme was tested on several fields in the North of Western Siberia, studied by seismic exploration using the common depth point method and deep drilling. The effectiveness of the algorithm is indirectly confirmed by comparing the detected anomalies with the orohydrography of the research area and on the sedimentation sections of the wave field. The refined morphology of structural surfaces obtained after accounting for long-period distortions should increase the efficiency of seismic exploration.