Multiple coverage refracted seismic surveys are used to track geological structures in areas with poor reflection image quality or to explore deep basement morphology and to study bedrock surfaces. Based on refracted wave theory, in refraction seismic records The refracted wave is used to image the subsurface refractive interface. The total depth refracting surface element superimposition imaging theory method is applied. The velocity analysis and dynamic correction calculation method for imaging the underground refraction interface by the common depth refracting surface element superimposition imaging technique are presented. The method of super-depth refraction point superposition imaging in the refracting wave developmental exploration area, and finally the correctness and practicability of the method are illustrated by the model and practical examples.
It is well known that when a seismic wave propagates downward to encounter a wave impedance interface, a reflected wave and a transmitted wave are generated. When the incident angle of the seismic wave reaches a critical angle, the transmitted wave glides along the transmission interface, which is called a sliding wave. The sliding wave is in the propagation. A new effect is generated, that is, new fluctuations are excited in the incident medium. This new wave is called a refracted wave, and its amplitude is not only stronger than the reflected wave, but also its attenuation is smaller than that of the reflected wave during propagation to the ground. Therefore, it shows a strong energy in the seismic record, and its signal-to-noise ratio is many times higher than that of the reflected wave. It has great credibility and high usable value.