Study on excitation effect of different combination modes of shear wave vibroseis

In order to solve the problems of less earth capture energy and shallow depth of shear wave signal transmission during the operation of shear wave vibroseis, and improve the exploration quality, the influence of different combination methods on excitation effect is studied. Through numerical simulation, the vibrator-simulated finite element model of combined shear wave vibroseis is established. Taking the earth capture energy, particle displacement amplitude and shear stress as evaluation indexes, the influence of three parameters, namely arrangement mode, spacing and number, on the combined excitation effect of shear wave vibroseis is deeply studied. The results show that, in terms of arrangement, compared with two SHY arrangements, two SHX vibroseis capture more energy in the earth when excited, and the particle displacement amplitude increases by 82.8% on average compared with a single vibroseis, and the sine wave shape of the shear stress curve is more complete, and the attenuation degree is smaller with the increase of depth; in terms of vibroseis spacing, compared with the combined vibroseis with the spacing of 3 m, 9 m and 12 m, the combined vibroseis with the spacing of 6 m has more ground capture energy, the particle displacement amplitude is increased by 62.5% on average compared with the single vibroseis, the shear stress distortion is smaller, and the attenuation is slower with the increase of depth. In terms of vibroseis number, compared with 4, 6 and 8 combined vibroseis, the loss rate of earth capture energy is the lowest when the 2 combined vibroseis excite, which is only 6.06% compared with the single vibroseis, and the particle displacement amplitude is increased by 56.5% on average compared with the single vibroseis, and the shear stress amplitude is larger. The research results can provide guidance for improving the excitation effect of shear wave vibroseis, and also provide reference for the study of combined excitation design of shear wave vibroseis.