Comparison of regularization methods for full-waveform inversion

Regularization is an important way to alleviate the ill-posedness of inversion and the characteristics of constrained solutions. Tikhonov regularization and total variation (TV) regularization are two regularization methods commonly used in full-waveform inversion. They can suppress high wavenumbers and protect the formation edge respectively. Two-parameter shaping regularization, hybrid two-parameter regularization, and sparse structure constraint regularization are developed on the basis of the former two and have their advantages. To systematically demonstrate the characte-ristics of different regularization methods, this paper makes a comparative analysis of the full-waveform inversion methods constrained by the five regularization methods. The anticline-overlap model and Marmousi model tests show that diffe-rent regularization methods all improve the inversion results to various degrees. Two-parameter shaping regularization combines the advantages of Tikhonov regularization and TV regularization, which improves the deep accuracy. Hybrid two-parameter regularization further improves the accuracy of shallow inversion. Compared with other methods, sparse structure constraint regularization has obvious advantages in both stratigraphic continuity and the description of edge structure. © 2022, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.