A new prestack three-parameter amplitude variation with offset inversion method

Abstract

Prestack seismic inversion is an important method in reservoir prediction and fluid identification. In this paper, we develop a new strategy to carry out a prestack three-parameter AVO inversion to obtain P-wave velocity, S-wave velocity, and density. Using the Aki and Richards equation to calculate the PP reflection coefficients, which is the approximation to the Zoeppritz PP equation, we re-derive the relationship between reflection coefficients and their partial derivatives with respect to P-wave velocity, S-wave velocity, and density. We transform the objective function into the form of matrix multiplication and solve it using a damped least-squares method and Tikhonov regularization method. Then we directly obtain the inversion results, including P-wave velocity, S-wave velocity and density. To demonstrate the validity of the proposed prestack inversion method, we set up a 1D forward simulation model and add uniform noise into the synthetic seismic records. Then we test the proposed method on the overthrust model and field data. In order to demonstrate its high accuracy and the efficiency of the Tikhonov regularization method, we carry out a damped least-squares inversion method using the same models as a comparison. We find that the proposed prestack seismic data AVO inversion method has higher anti-noise capability, accuracy, and efficiency, both in synthetic records and field data using the Tikhonov regularization method.