Abstract

Summary With the development of vibroseis technology, the requirements for vibroseis sweeping bandwidth have been continuously increased in recent years. Some users simply increase the high-frequency cutoff frequency, which causes many problems. Especially in loose surface areas such as pastures and farmland, high-frequency distortion occurs, seriously affecting the data quality. In the Chepaizi area of the Junggar Basin, broadband sweep signals of 1.5–150Hz are used for construction excitation. The high-frequency distortion is serious and the high-frequency energy is insufficient. To this end, starting from the high-frequency distortion phenomenon, we established vibroseis and surface vibration model, and conducted an in-depth study of the source vibration output force signal. The analysis shows that due to near-surface reasons, a large phase difference occurs between the high-frequency weight and the plate acceleration. This causes overloading of the vibroseis system resulting in high frequency distortion. Therefore, a method of high-frequency optimized energy compensation sweeping technology is further proposed to solve high-frequency distortion. Experimental comparison shows that this method can improve the stability of high-frequency output signals and reduce high-frequency distortion, and also provide help for solving similar problems in the future.