Method for constructing azimuth angle-apparent velocity radar map by using virtual seismic source scanning

Abstract

The invention discloses a method for constructing an azimuth angle-apparent velocity radar map by using virtual seismic source scanning. According to the method, on the theoretical basis that seismic waves incident at different vertical angles have different horizontal apparent velocities, seismic wave propagation time from a virtual seismic source to each detector in a receiving array under different apparent velocity conditions is calculated by setting the virtual seismic source in different directions of a plane circumference, seismic wave superposition energy in a corresponding time period is extracted, and a radar map capable of reflecting the plane propagation direction and the apparent velocity of the seismic waves is obtained. According to the method, the spatial distribution of various seismic waves can be intuitively reflected, a good data analysis means is provided for noise source analysis, detector combination parameter design and the like, and the seismic wave apparent velocity analysis precision can be greatly improved on the premise that the field production mode is not changed.

Description

technical field [0001] The invention relates to the field of seismic exploration, in particular to a method for establishing a virtual seismic source by analyzing shot points, then scanning and constructing an azimuth-apparent velocity radar map by using the virtual seismic source, and finally completing the analysis of interference waves. Background technique [0002] High-density square receiving array (also called box wave) is a commonly used field interference wave investigation method in artificial seismic exploration. Because it has a receiving density several times higher than the normal production receiving array, and there is no dead angle receiving data in 360° on the plane, it can High-density collection of various types of seismic waves propagating from all directions is generally carried out before formal seismic operations to determine the source of interference waves in the work area and assist in the design of geophone combination parameters. The existing box...

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Problems solved by technology

However, the existing methods still have the following defects: 1. Since the actual receiving arrangement is generally arranged at equal intervals in squares, the number of seismic traces in the gathers extracted by angular traces is not uniform, which reduces the accuracy of azimuth angle analysis; 2. Seismic waves Spherical rather than planar propagation in the formation, the nonlinear event shape in the seismic record reduces the accuracy of apparent velocity analysis; 3. Accompanied by spherical propagation, the energy received by different geophones in the array is inconsistent due to the distance from the shot point. As a result, the accuracy of overlay or correlation analysis is reduced

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