Sea-tunnel joint seismic detection method and system based on ocean noise

Abstract

The invention belongs to the technical field of marine seismic detection, in particular to a sea-tunnel joint seismic detection method and system based on marine noise. Wherein, the method includes synchronously collecting the first seismic signal, the second seismic signal and the third seismic signal, these signals are formed by ocean noise propagating to the tunnel wall, the sea surface and the sea respectively after encountering bad geological bodies; for the second seismic signal Carry out preliminary geological wave velocity inversion to obtain the initial geological wave velocity model, and then perform beamforming processing on the basis of the third seismic signal at the abnormal wave velocity position to invert and correct the initial geological wave velocity model; based on the corrected initial geological wave velocity model, invert the first seismic signal The seismic section in front of the working face of the tunnel boring machine was obtained by performing reverse time migration imaging.

Description

technical field [0001] The invention belongs to the technical field of marine seismic detection, in particular to a sea-tunnel joint seismic detection method and system based on marine noise. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Submarine tunnels are covered with seawater, and the cost of offshore exploration is high. It is difficult to ascertain the unfavorable geological conditions along the tunnel in the early stage of construction, especially under the construction conditions of tunnel boring machines, facing complex construction environments, and encountering unfavorable geological conditions such as fault fracture zones and weathered deep grooves Once it is not handled properly, it is easy to cause disasters such as water and mud inrush, landslides, etc., resulting in serious consequences. Compared with post-treatment, pr...

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Problems solved by technology

[0006] (1) Problems in the observation in the tunnel: the seismic detection data received by the receiving sensor in the tunnel rely on a relatively accurate initial geological wave velocity model in the imaging process, and it is difficult to realize the tunnel depth by only relying on the observation data in the tunnel. Accurate inversion of geological wave velocity in front of the face;

[0007] (2) Problems in ocean streamer observation: Ocean observation systems can provide an overview of seabed geological wave velocity, but different observation systems have their own emphasis. For example, the sea surface horizontal streamer seismic observation system is sensitive to horizontal layered geological structures, and the vertical cable Sensitive to steep geological structures, a single observation method cannot accurately measure the wave velocity information of various geological structures

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