Method for suppressing multiple reflected refractive waves by vertical double vibration sources based on kinematics

Abstract

The invention discloses a method for suppressing multiple reflected refractive waves by vertical double vibration sources based on kinematics. According to the method, based on a propagation path of the multiple reflected refractive waves, a time curve of the multiple reflected refractive waves and target layer reflected waves is derived in the presence of an excitation well depth, and a verticaldouble vibration source combined excitation method is proposed on the basis of the curve. Combined double vibration sources are disposed at different depths of the same position on the ground, a vertical relative distance between the two vibration sources is controlled, the two vibration sources are stimulated at the same time, time difference interference between two columns of earthquake waves generated by the two vibration sources is canceled in a propagation process, and the purposes of suppressing the multiple reflected refractive waves and reducing the influence on the target layer reflected waves are achieved. The problems of low resolution and low signal to noise ratio of the target layer reflected waves in an earthquake record caused by low speed zone development in the earthquakeexploration work areas such as loess plateau, sandy land and the like are solved, the overall working efficiency of earthquake exploration is improved, and it is conducive to the refined interpretation of coal and coalbed methane reservoirs.

Description

technical field [0001] The invention relates to a kinematics-based method for suppressing multiple reflection and refraction waves with vertical double seismic sources, and belongs to the technical field of oil and gas seismic exploration. Background technique [0002] China is the country with the widest loess distribution and the largest thickness in the world. Under the loess cover, there are abundant energy resources, mainly coal, coal bed methane, and oil and natural gas. These fossil energy sources are mainly explored by means of artificial earthquakes. Due to the unique physical properties of the loess plateau, the pores are developed, loose and dry, the density is low, and the wave velocity is low, which leads to serious attenuation of seismic wave energy, serious high-frequency attenuation caused by low signal-to-noise ratio, and strong interference such as surface waves, ringing earthquakes, and multiple waves. And other issues. With the transformation of energy ...

AI Technical Summary

Problems solved by technology

[0033] In order to solve the deficiencies in the prior art, the present invention discloses a method for suppressing multiple reflection and refraction waves based on kinematics vertical double seismic sources. Due to the development of low-velocity zones in the exploration work area, the problem of low reflection wave resolution and signal-to-noise ratio in the seismic records of the target layer has improved the overall work efficiency of seismic exploration and is conducive to the fine interpretation of coal and coalbed methane reservoirs

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